p. s m" j i»? I TEXflS HGRIGULTURHL EXPERIMENT STHTIONS. BULxhETIN No. s3. Veterinary Section-OCTOBER, 1899—I/ive Stock. TEXAS FEVER. POSTOFFICEZ COLLEGE STATION, BRAZOSICO“ TEXAS. J. J. PASTORIZA PRINTING s; LITHO. 00. HOUSTON, 1899. [531 TEXHS HGRIGULTURHL EXPERIMENT STHTIONS. OFFICERS. GOVERNING BOARD. (BOARD OF DIRECTORS A. at M. COLLEGE.) M. SANSOM, President . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..Alvarado. F. A. REIOHARDT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Houst0n. F. P. HOLLAND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..Dal1as. D. A. PAULUS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..Hallettsville. P. H. TOBIN . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . .Denison. A. P. SMYTH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Ma.rt. J 01m W. KOKERNOT . . . . . . . . . . . . . . . . . . . . . . . . . . . ..San Antonio. JEFFERsON JOHNSON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. Austin. STATION STAFF. THE PRESIDENT AND TREASURER OF THE COLLEGE. J. H. CONNELL, M. SO . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . Director. H. H. HARRINGTON, M. Sc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chemist. M. FRANCIS, 1). V. M ................................. . .Veterina.rian. R. H. PRICE, B. S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .» . . . . ..Horticulturist. B. C. PITTUOK, B. S. A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Agriculturist. P. S. TILSON, M. S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Associate Chemist. W. C. MARTIN, B. S. . .. . . . . . . . . . . . . . . . . . . . . . . . . . .. Assistant Chemist. H. C. KYLE, B. S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .F0reman of Farm. .1. G. HARRISON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. Bookkeeper. A. M. FERGUSON, M. SO. . . . . . . . . . . . . . . . . . .. Assistant Horticulturist SUPERINTENDENT OF BEEVILLE STATlONi S. A. MCHENRY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. Beeville, Bee County. NOTE.-The main station is located on the grounds of the Agricultural and Mechanical College in Brazos County. The postofice address is COLLEGE STATION, TEXAS. Reports are sent free of cost to farmers of the State upon application to the Director. I541 TEXAS FEVER. Experiments made by the Texas Experiment Station, in co-op- eration with the Missouri Experiment Station and the Missouri State Board of Agriculture, in im- munizing Northern breeding cattle against Texas Fever. BY M. FRANCIS, Veterinarian, Texas Experiment Station, AND J. W. CONNAWAY, Veterinarian, Missouri Experiment Station. For many years Texas Fever has been a serious obstacle to the growth of trade in blooded breeding cattle between the Northern breeders and the Southern cattle raisers. The losses from this malady, in cattle shipped from the North, are rarely less than 40 per cent, and frequently '70 per cent. or more. The pressing need for some practical method of preventing these losses has led the Experiment Stations of Missouri. and “Pexas and t-he Missouri State Board of Agriculture to undertake the experiments rc- ported herein. This co-operative work was begun in 1896, and is still in prog- ress. The interests of the cattle industry demand that the re- sults attained up to the present time be presented in official form. There is probably much work yet to be done before the methods that can now in careful hands be employed with a degree of suc- cess, reach the perfection that is desirable. The work reported herein includes: I. Experiments to determine whether sterile blood serum of immune Southern cattle contains any chemical substance of the nature of an antitoxin, or toxin that could be utilized practi- cally in stimulating at least a passive immunity in suscepti- ble cattle. ll. Experiments on immunizing cattle by infection with the microparasite of the disease by means of tick infestation. Ill. Experiments on immunizing cattle by infection with the microparasite of the disease through blood inoculation. These different lines of experiments will be discussed in the order named. Only a brief discussion of the first two lines of work will be given in this bulletin. The final results of the experiments on inoculation with sterile serum show that such. material possesses no protective properties. Immanizing by t/ich infestation can be employed with success, [55] 56 TEXAS AGRICULTURAL "EXPERIMENT STATIONS. but on account of maintaining a quarantined pasture, and the necessity of hand-feeding in the case of calves of non-immune cows; this method is not as desirable as that of blood inoculation. In the blood inoculation experiments over 400 pure bred cattle have been used. The losses from inoculation and from subse- quent exposure to infected pastures in Texas, have been less than 8 per cent. I. EXPERIMENTS ON INOCULATION OF NORTHERN CATTLE WITH STERILE SERUM FROM IM- MUNE SOUTHERN CATTLE. These experiments were made to determine whether the serum of the blood of immune Southern cattle contains any chemical substance, apart from the living organism of the disease, that might be used in a practical way in bringing about immunity in susceptible cattle. The value of such material would be that the danger of the development of an acute fever that attaches to other methods, as “tick infestation” and “blood inoculation,” would be avoided. Moreover, the material could be transported and used at any distance without the dangers from septicaemia that are liable to arise from the shipment to a distance of blood containing the living parasites. J The discovery of the protective properties of the serum of ani- mals made immune to a certain disease, as diphtheria and tetanus, led to the somewhat broad statement by Behring, one of the chief investigators of serum therapy, “that if an animal has acquired immunity against a disease-producing micro-organism, or its toxins, the serum from the blood of the immunized animal will prepent the disease in another susceptible animal.” While Texas fever is due to protozoon micro-parasites, instead of bacteria, as is the case of diphtheria, the immunity attained on recovery from an attack of the disease appears to be as great as in the latter malady. And it was not unreasonable to suppose that, in the physiological processes by means of which immunity is es- tablished against Texas fever, some new product should be formed which might stimulate in the cells of a susceptible animal a con- dition or metabolism like that of the cells of the immune animal, and thus establish at least a passive immunity that would tide the animal over the danger-period, following tick infestation. The first experiment with sterile serum inoculation was made in the fall of 1896 on an 8-year-old cow. 200 cc. of serum were inoculated subcutaneously during a couple of weeks previous to infesting her with ticks. This cow was inoculated with 80 cc. more of serum after the infestation. ‘This inoculation began September 2d; the infection was made September 16th, and the TEXAS FEVER. 5'7 animal was kept under observation until November 2d; morning and afternoon temperatures were taken. During this time there was no elevation of temperature, except on the afternoon of the 17th and 18th days following tick infestation; 103.8 F. and 106. F. Outwardly the animal appeared to be in perfect health throughout the experiment. ' The following spring, in conjunction with the Mississippi Ex- periment Station, a lot of young cattle and one cow were inocu- lated at Enterprise, Miss. These had all sickened from acci- dental tick infestation. Twelve other cattle had died, all but two of them being adult animals. All the inoculated animals lived. A full report appears in bulletin N o. 37 of the Missouri Experi- ment Station, where the method of preparing the serum is de- scribed. These experiments were not regarded as conclusive, since the season of the year at which the work was done and youthfulness v of most of the animals inoculated, might account for the result. ln order to give the matter a more decisive test, a larger experi- ment was planned for the following summer, and carried out in conjunction with the Mississippi Experiment Station in June and July, 1897. A full report of the results upon the cattle shipped to the Mississippi Station appears in bulletin N 0L 42 of that Sta- tion. Only a summary is here given. Eleven head were inoculated, eight of these at the Missouri Station before shipping, and three after their arrival in Missis- sippi. These cattle varied in age from 1 1-2 years to 11 years. They were inoculated daily with serum in doses of 4O to 60 cc., according to size of animal. _Tl1e minimum quantity injected into any one animal was 146 cc. ; the maximum quantity was 772 cc. After tick infestation, all of them suffered from acute at- tacks of the fever, and all except two of the younger animals (2- year-old) died. During the same summer five more head were inoculated at the Missouri Station, two mature cows and three yearling steers. The material used in this experiment came from difierent sources than that used in the Mississippi experiment-one lot was ob- tained from the Texas Station, and another from a ‘Texas animal in Kansas City. One cow received subcutaneously a total of 230 cc.; the other one 420 cc., in doses of 20 to 40 cc. over a period of two weeks or more immediately preceding tick infestation. Both died from acute attacks of the fever following tick infestation. Not the least mitigation in severity of the attack appears to have resulted from the use of serum. * The three yearling Jersey steers were inoculated with doses of 10 cc., to 40 cc., over a period of two weeks; one steer received 144 cc., another 320 cc., and the third 180 cc. All of these suf- 58 TEXAS AGRICULTURAL EXPERIMENT STATIONS. fered from attacks of the fever after tick infestation, but recov- ered. A check animal, not inoculated, appeared to suffer more severely; this animal, however, was somewhat younger and less vigorous. While the desired economic end of this experiment was not at- tained, the data supplied in regard to the effects of tick infesta- tion are valuable in the experiments that follow. It appears that so far ‘as experiments have yet shown, the only way of producing immunity is through an actual attack of the disease, induced either by tick infestation or by inoculation of in- fected blood. II. EXPERIMENTS ON IMMUNIZIN G BY TICK INFES- TATION OF YOUNG CATTLE. . _ _.._,__“_ The fact has long been known to stockmen that calves are more resistant to Texas fever than mature cattle. The same effect has been observed in all scientific investigations of this disease Where young and mature cattle were used. In the investigations of Smith and Kilbourne into the nature and means of transmitting Texas fever, a large per cent. of adult susceptible cattle used in their experiments died when exposed to infection, while only a small per cent of the young animals succumbed. The case of the dairy herd at Enterprise, Miss. (mentioned under “serum inocu- lation”), illustrates, in a marked manner, the greater resistance of the young animals as compared with those more mature. In this lot were eleven head of grown cattle, four yearlings and twelve calves. Out of this number, all of the grown cattle, ex- cept one, died; while two of the yearlings and all of the calves lived. Those that survived had been grossly infested with ticks and suffered more or less fro-m fever. In the serum experiments of the following summer, the same difference was noted between young and old cattle in resisting the disease. These observations led to the experiment to test the practica- bility of immunizing cattle on Northern stock farms by tick in- festation. This work was begun in 1897, and has been continued to the present time. The following animals were used in the experiments in 1897 : No. 1. “Jerry,” a yearling Jersey steer. No. 2. “Spot,” a yearling Jersey steer. No. 3. “Red,” a yearling Jersey steer. No. 4. “Fawnl,” Jersey steer 10 months old. No. 5. “Durham,” Shorthorn steer 14 months old. No. 6. “Estes,” grade Shorthorn bull 2 months old. No. '21. Jersey bull calf, 6 weeks old; dam “Alpha Elf.” No. 8. Jersey bull calf, 5 Weeks old; dam “College Nina.” TEXAS FEVER. 59 No. 9. Jersey bull calf; 3 weeks old; dam “May Bates.” No. 10. Jersey bull calf, 3 weeks old; dam “Mattit-uck.” N0. 11. Jersey bull calf, 3 weeks old; dam “Daisy Bates 3d.” No. 12. Jersey bull calf, 2 weeks old; dam “Daisy Bates.” In 1898 all the above, except Nos. 4-, 6, 11 and 12, were rein- fested, and the following animals were added to the experiment: No. 13. “Holstein heifer “Bessie,” 10 months old. No. 14. Holstein heifer “Beauty,” 10 months old. N o. 15. Jersey bull calf, 4 weeks old; dam “May Bates.” No. 16. Jersey bull calf, 2 weeks old; dam “Mattituek 2nd. No. 17. Jersey bull calf, 3 1-2 weeks old; dam “Daisy Bates No. 18. Jersey bull calf, 5 weeks old; dam “Mary Herbert.” No. 19. Jersey bull calf, 3 weeks old; dam “Alpha Elf.” No. 20. Jersey bull calf, 5 Weeks old; dam “Mattituck.” G l\1To. 21. Jersey bull calf, 3 1-2 Weeks old; dam “Bachelor 1r .” In 1899 six aniimals of the first group (Nos. 1, 2, 3, 5, '7 and 8) were reinfested for a third season. In. the second group N cs. 13, 15, 16, 19 and 21 were reinfested a second season. Certain individuals and groups in the above lot of animals were treated differently; some were grossly and continuously infested; while others were but slightly or intermittently infested. It will be of interest to notice briefly these individual cases and groups. No. 1, “Jerry,” was infested July 27th, 1897, with several hun- dred fever ticks. These had nearly all matured and fallen off by September 1st. The steer remained free from ticks about a month, and was on October 5th reinfested artificially with sev- eral hundred. In addition, the steer became infested with many more from the pasture. An acute attack of the fever resulted from the first infestation; the morning temperature on the twelfth day after infestation was 105 F, and continued high for four days, when it fell to nlormal. The afternoon temperature during this period ranged from 105 to 107 E The steer fell off some in flesh, became somewhat gaunt, but continued to graze. He made a good recovery, and at the time of the second infesta- tion was lively and apparently in perfect health. The second more gross infestation produced no fever. Temperature observa- tions were continued until November 1st. The animal went into winter quarters in excellent condition. He was grossly rein- fested the following summer and fall (1.898), but showed no evi- dence of fever. Through the spring, summer and fall of 1899 he was exposed to a presumably more severe infection in the quar- antine territory, at College Station, 'I‘e>1as. The animal remained in perfect health. The following group of Jersey steers, No. 2, “Spot ;” No. 3, 6O TEXAS AGRICULTURAL EXPERIMENT STATIONS. “Red,” and N0. 4, “Fawn,” ages given above, were infested August 28th, 1897, with about 200 ticks each. They had _also been placed a week before upon a pasture that proved to be gross- ly infested with ticks (from “single dipped” Texas cattle). Morning and evening temperatures were recorded from date of infestation until November 1st. A few mature ticks were found September 13th, twenty days after infestation. In a few days mature ticks were numerous, and continued so for a week. On September 28th, these steers were almost free from the ticks com- ing from the artificial infestation. This artificial infestation produced scarcely any elevation of temperature in No. 2 and No. 3. In No. 4 several high afternoon temperatures had been ob- served, but nothing indicating a continuous fever period. On Oc- tober 29th, it was observed that the animals were well infested with small ticks picked up from the pasture. From October 4th to 9th, No. 2, “Spot,” had a fever period, morning temperature ranging from 102.7 to 105.7 F., and even- ing temperatures for two weeks from 103.7 to 107.7 F. The ani- nial became gaunt, laid down much of the time, and had little appetite. On October 11th, the morning temperature was normal, and continued so until November 1st, when regular observations ceased. These animals were not free from ticks until well into the winter. A few immature ticks were found as late as J an-‘ uary 3d. _ No. 3, “Red,” showed no outward signs of fever until October 20th, but from October 7th to 16th the evening temperature had ranged from 103.5 to 106.4, and the morning temperature from 101 to 103. The calf had fallen off some in flesh. The morn- ing temperature, October 20th, as 1033; evening temperature 106.4, calf stupid. October 21st, morning 1.04, evening 106.2, calf sick. October 22d, morning 104, evening 105.9, calf dull and gaunt. October 23d, morning 101.5, evening 105.4. October ' 24th, temperature normal. Calf has been grossly and continu- ously infested with ticks. No. 4, “Fawn.” This calf showed but little signs of fever from the first infestation. From August 1st to September 25th, the morning temperature remained normal, and only an occasional high eveni-nwg temperature occurred. On September 26th, the evening temperature arose to 104, and from that date until Octo- ber 30th, the evening temperatures remained high, ranging from 103.7 to 106.3 F., only an occasional normal temperature being observed. From the 23rd to the 29th the temperature ranged from 103 to 103.6, but through the greater part of the experiment the morning temperature remained normal. The continuous and severe infestation to which these calves were subjected from running on grossly infested pasture caused TEXAS FEVER. 61 them to fall off greatly in flesh. They went into winter quarters in bad condition, with skin harsh and scurfy. ‘Dhis condition was, however, in part due to lack of nutrition; the pasture became dry and short. On December 31st, calf No. 4 died from accident, having been horned into the manger, probably by a Texas cow that was kept in the same pen. No. 2 and No. 3 improved during the winter, and were put on the grass in the spring in fair condition. In July, 1898, both were reinfested with Texas ticks. These matured, and the steers became grossly reinfested from the pas- tures. Neither of these animals showed any signs of sickness dur- ing the season. They were never odff food and were in good condi- tion at the end of the season. They had evidently become immune from the severe infestation of the previous year. These two steers were shipped with others to the Texas Experiment Station on December 28th, 1898, and have been on infested grounds since January 1st. No signs of fever have appeared. The temperature records and tests of the blood by means of haematokrit show that these steers were fully immuned by the tick infestation at the North. No. 5, “Durham,” shorthorn steer, 14c months old. This steer was used as a check on seven head of double dipped Texas cattle. He was exposed on the same grounds, a small pasture, from July 19th to October 27th, and during this time was observed almost daily forr ticks. The dipping proved so nearly perfect that during the summer and fall only five ticks were found on this animal, and but ten ticks on the seven head of Texas steers, as a result of in- fection of the pasture. No doubt many ticks escaped observation, but it is safe to say that during the entire season not more than twenty-five or fifty ticks infested this steer. This very mild nat- ural infestation gave rise to no serious symptoms, and the animal remained in good condition. This steer was infested the follow- ing year to determine whether so mild an infestation would prove protective against a somewhat severe infestation. On July 21st, 1898, several hundred Texas ticks were applied to this animal, and later in the season he became grossly infested from the pas- turet Ripe ticks were found on the steer 23 days after infesta- tion. The animal showed som.e high temperature and some de- pression on hot afternoons in July and August, but no serious ill- ness occurred. The steer did well through September. In Octo- ber he fell oif some on account of short pasturagge turd gross tick infestation. At the close if the season the steer was fed for awhile, and was shipped in fair condition, on December 28th to the Texas Experiment Station, where he has been exposed si-nce January 1, 1899, without showing any signs of fever. 62 TEXAS AGRICULTURAL EXPERIMENT STATIONS. TICK INFESTATION OF YOUNG GALVES. In the fall of 1897 six young Jersey bull calves two to six weeks old (Nos. 7, 8, 9, 10, 11, 12) were put in a quarantine pen and infested artificially with from twenty-five to fifty ticks. After these had matured and dropped off, the calves were infested again with from seventy-five to two hundred ticks. These also matured Some of the calves for a time were off feed and a little dull and gaunt, but at no time during the infestation period were any of them seriously sick. The thermometer showed some fever in each calf. This, however, was of short duration and of mild character. From fear of carrying the infection into the barns, these calves were kept in the quarantine pens somewhat late in the season, and were exposed to a few sharp winter storms, from which they all - suffered severly, and two (Nos. 11 and 12) died. The post mor- tem showed no indication of Texas fever. The four remaining Group of Young Calves, Two to Six Weeks Old. Infested Artificially with Ticks. calves were put i-n the barns December 12th, and in a few weeks were in excellent condition. These calves were infested again the following summer. July 28th, 1898, bull No. '7 was infested with about 400 ticks» July 7th, bull No. 8 was infested with 300 ticks, and :gain September 10th with 500. Bull No. 10 was infested July 28th with 200 ticks, and again on September 10th with 500. Up to the time of maturing the first crop of ticks, none of these bulls had shown any period of fever, only an occasional high temperature was noted on very warm days. On the 28th of August, N o. 10, after becoming quite free from ticks, appeared somewhat gaunt and had diarrhoea, but appeared quite well in a few days. In addition to the artificial infestatiorn, these bulls were quite grossly infested with ticks hatched on the pastures. As the re- sult of excessive tick infestation, and lack of proper nourishment from dry condition of pasture, these young bulls fell off consid- erably in flesh, and in September one of them, No. 10, developed TEXAS FEVER. 63 an acute attack of fever. The bull was found sick on September 30th, and died during the day. Thepost-mortem showed typical lesions of Texas fever. On June 21st, 1899, bull N0. 7 was artificially infested for the third season with several hundred ticks, and later became gross- ly infested from the pastures and was not free from ticks until October 1st. To test the immunity of this animal more severely, he was also inoculated with large doses of infected blood from a Texas cow. A dose of 7.5 co. was given June 15th, and a second dose of 10 cc. August 4th. Daily temperature records were kept, and during this time no rise of temperature indicating a fever period was shown. The blood was tested from time to time by means of the haematokrit to determine variation in the percent- age of corpuscles ; but little variation from normal was observed. The bull appeared to be in perfect health during the entire sea- son. The picture of this animal as he appeared at the close of the experiment is shown -on page 64. Bull No. 8 was shipped to Texas December 28th, 1898, and has been exposed to the ‘natural infection on a pasture at College Sta- tion since January 1st, 1899. The bull has remained in perfect health throughout the season. Temperature records and blood examinations were made twice a Week. Bull No. 9 was killed March 20th for a class demonstration, as the calf was infected with “Hoose.” The post-mortem showed the parasitic worms of the disease almost plugging many of the small bronchi. INFESTATIONS OF 1898 AND 1899. The group of animals from Nos. 13 to 21 was infested for the first time i-n 1898. The twfo Holstein heifers, Nos». 13 and 1-1, were infested August 13th, with 300 ticks each, and later they “became grossly infested from the pasture. The first infestation was made during the warmest part of the summer. The heifers showed high evening temperatures through the liot Weather. Heifer No. 14 suffered more severely, and in October developed an acute case of the fever, dying October 8th, fifty-six days after the first infestation. The post-mortem showed the usual lesions of Texas fever, such as bloody urine in the bladder, softened spleen, yellow liver, and bloodless condition of the flesh. This heifer was also found to be affected with “Hoose.” The small bronchi were badly infested with the parasitic worms of this disease, and pneumonic areas were found in the lungs. The long time that elapsed after the first infestation and be- fore the death of this animal, makes it probable that she would y have lived if she had not been subjected too soon to the gross 64 TEXAS AGRICULTURAL EXPERIMENT STATIONS. .Wv_U~..F SH?’ ciwawmouc- W..-fl0> UCOUOW wO Uimm HQ O-wwflnv M==O> m0 9.9-0 TEXAS FEVER. ‘ 65 tick infestation that occurred on the pasture, and had not been suffering from another disease. I The Holstein that survived (No. 13) did poorly through the winter, but improved when put on pasture in the spring, and was in fine condition June 21st, 1899, when she Was reinfested with several hundred ticks. In addition to the tick infestation this heifer was inoculated June 15th with 6.5 cc. infected blood from a Texas cow, and on August 4th with 8 cc. The heifer has been in the best of health throughout the season, and is no doubt well immunized. t (HISTORY or THE SEVEN JERSEY BULLS, NOS. 15 TO 21, INCLUSIVE.) The seven Jersey bulls, Nos. 15, 16, 1'7, 18, 19, 2O and 21, were infested with Texas fever ticks September 23d, 1898\ From 50 to 100 ticks were applied to each, and they matured on all the bulls. Four of them showed scarcely any rise in temperature, . while three showed more or less fever. All these had diarrhoea, no doubt in part due to change of food, from early weaning. One, No. 18, died from scours January 16, 1899, 115 days after the in- festation; the post-mortem showed no evidences of Texas fever. All the other calves passed the winter safely, and, with the excep- tion of No. 20, were well infested the following season, August 1st to November 1st, 1899. No. 20 died from u-nknown cause in the spring of 1899, after being put on pasture. As this death oc- curred before any of the calves had been reinfested and the pasture was shown to be free from ticks, the death could not have been due to Texas fever. In addition to the tick infestation, all the calves were inoculated with infected blood. June 15th, previous to the secornd period of I infestation, 3 cc. of blood from a Texas cow was injected subcu- i’. taneously into bulls Nos. 15, 16, 17 and 21. They were again in- .- oculated on August 4th with 5 cc. each from the same animal. j No. 19 was inoculated June 13th with cc. from a native re- 7 covered cow, and six days later infested with several hundred ticks. i, June 29th, sixteen days after the inoculation, the calf appeared to be in good health, the temperature was normal, and the percentage rof blood corpuscles from haematokrit readings was 36 per cent. (about normal). On July 6, twenty-third day after inoculation and fifteen daysafter tick infestation, the percentage of corpuscles ~had fallen to 2O per cent, the morning temperature was 104.9, and evening temperature 106.5 F. ; ticks in second moult, animal ijioif feed, sluggish and gaunt. This condition appears to have i arisen from the tick infestation rather than from the blood inocula- tion. No rise of fever was noted at the usual period after inocula- tion. This calf was a little dumpish all summer, but has fed well. 66 TEXAS AGRICULTURAL EXPERIMENT STATIONS. All the other calves showed no outward symptoms of illness ap- parent to the average observer; but all showed through the season some elevation of temperature and destruction of blood corpuscles, as determined by means of the haematokrit. Bull No. 15 showed a dimunition of corpuscles from 3'7 to l8 per cent; No. 1.6, from 44 to 2O per cent; No. 1'7 fell to 24 per cent; No. 21 shorwed but little destruction of corpuscles. The greatest destruction occurred not immediately following the inoculation and tick infestation, but in the fall after the pastures had become dry and grass scanty. Acute Case of Texas Fever Induced by Artificial Tick Infestation. SUMMARY AND CONCLUSIONS-—TICK INFESTATTON. It will be seen from the history of the above twenty-one head of young cattle that but one died from acute attack of the fever within the usual period of thirteen to twenty days following tick infestation, and that this one, No. 6, a Q-month-old calf, was pur- posely infested with an excessively large number of ticks. The first crop of ticks matured on all the other cattle, and but few of the animals showed any distressing symptoms of the fever from the first infestation. The yearlings that were mildly or intermit- tently infested the first season did not suffer profound nutritive disturbances noted in others that were grossly and continuously infested. (Contrast steers Nos. 1 and 5 with steers Nos. 2, 3 and 4, all infested in 1897.) Young calves, from 2 to 6 weeks TEXAS FEVER. 67 old, infested mildly in the fall, suffered but little from the infes- tation, but were not fully immunized against the effects 0f gross infestation the following year, after being free from ticks for seven months. Bull No. 10 died from relapse in the fall of the second season (1899), and others in the 1899 group, while apparently in good health, showed considerable destruction of blood co-rpuscles. _ An acute fatal relapse occurred in two animals (Nos. 10 and 14) following second gross infestation; both had matured ticks earlier in the same season and one (No. 10, mentioned above) had car- ried ripe ticks the previous fall. Lack of proper nourishment and a concurrent disease are to be regarded as contributing largely to these relapses. Animals that had been well infested with the fever ticks at the North, proved immune when exposed to the more prolonged in- festation occuring in the South. Five head of the experiment animals died from other causes than Texas fever. Jersey bull calves from the dairy herd were mainly used in the experiments. They were taken from the mother quite young and fed by hand. Their care through the win- ter was such as given ordinary stock cattle, and not that which is given to breeding animals intended for sale. These losses, largely preventable, would probably not have been so great in calves of the beef breeds intended for sale, instead of experiment. A quarantine pasture has been maintained at the Missouri Sta- tion through four summers, and during this time no deaths have occurred in the farm cattle grazing in an adjacent pasture, sep- arated by a space of fifteen feet. From the above We may conclude that complete immunity is not acquired by the young animal through a single mild infestation with fever ticks, but that the immunizing process is a gradual one requiring several months for its completion. The preferable way of effecting immunity by this method would be to give a mild infestation as early in the season as possible, and reinfest at intervals with a gradually increased number of ticks; permitting the animal to be free from ticks for a short time before reinfestin-g and seeing that all fever from previous infestation had passed. Gross reinfestation from the pasture, before the animal is ready to bear it, may be prevented by one change to a clean pas- ture during the season. One of the most important requisites in immunizing is that the calf be well nourished throughout the immunizing period. Other- wise stunting of the animal will occur, and occasionally a fatal re- lapse. From the fact that exclusive hand-feeding is not desirable in rais- ing calves of the beef breeds, the tick infestation method cannot 68 TEXAS AGRICULTURAL EXPERIMENT STATIONS. come into large use in immunizing these animals, unless the breeder finds it profitable to maintaiin a herd of immune cows. There are no very serious difficulties in the way of maintaining infected pas- tures on Northern stock farms, and the animal that has stood the test of tick infestation at the North carries with him his own cer- tificate of immunity, namely, the ticks themselves or their ineiface- able scars. The blood inoculation method to be described may, however, meet all requirements. "Ran "JERRY" euu. No. a DURHAM" “sPoT Group of Five Steers After Eight Months Exposure to Infected Pasture in Texas. They have carried great numbers of Ticks, but have shown no signs of Texas Fever. In‘ order to make a practical test of the degree of immunity broughtabout by infestation with ticks, the following animals were shipped to the Texas Experiment Station in December, 1898, viz: Bull No. 8, “Jerry,” “Spot,” “Red” and “Durham.” They arrived at the station in good order on January 1st, 1.899. On January 3rd they were sent to the cattle pasture. This pas- ture lies directly west of the depot and contains about 600 acres. 1t is thickly wooded with trees and undergrowth. In the north and west portions of it small prairies occur. The water supply is from a branch which passes through it and from a large tank in the north corner. There are cattle in this pasture the whole year. At this time there were fifty or more wintering there. There were some considerable number of ticks on the native cat- tle at the time, so that these grounds seemed the most suitable on which to make the test. a January 21st.-—The cattle are losing flesh, evidently from lack of food. Arranged to have them fed cotton seed meal twice a week. TEXAS FEVER. , 69 January 28th.—Ticks found 0n all the steers except No. 8. N o fever or blood destruction present. February 3rd.—-Cold, wet weather set in today, which increased in severity until February 11th, by which time the temperature had fallen to zero. About twenty-five mature ticks found on the cattle during this cold spell. Fr-om January 28th until August 31st these cattle were fed twice a week and their temperature, the condition of their blood and the number of ticks (Boophilus bovis) ascertained and recorded. The gap in the blood record was due to an accident to the apparatus. The percentage of red blood corpuseles was determined by the haematokrit. The numbers of the ticks must be regarded as esti- mates. When there were but a few, say twenty-five or less, they were counted, but in those cases where there were hundreds present, the numbers given are to be regarded as guesses». No fever, blood-destruction or other evidence of Texas fever occurred among these cattle at any time during the season, though they were subjected to the most severe test possible. Tick Eggs and Young Ticks. 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EXPERIMENTS TO DIDTERMINE THE PRACTlF-- ABILITY OF IMMUNIZING SUSOEPTIBLE CATTLE AGAINST TEXAS FEVER BY INOOD-OLATION WITH INFECTED BLOOD. The investigations made by Smith and Kilbourne in.t0 the path ology of Texas fever have shown, among other things, that the disease may be produced by inoculation with infected blood; and that the mortality from such attacks is, as a rule, much lower than in those cases which have been induced by natural tick infestation. It is well known that a considerable piarcenitage of animals recover from the disease, anid that they subsequently resist the infection when exposed to it in its most viruheiit form. This shows that a considerable de ree of immunitv is brought about. in some wa -' b ~ ' . 1'5 the first attack. Moreover, certain oiiiiéers of the (‘Queensland (Australia) government, notably, C‘ J. Pound, director oi the a M, '-"""'ilillllllk Group of Aberdeen Angus Bulls After One Season's Exposure In South Texas. Inoculated with Immune Blood. Stock Institute, and J. Sidney Hunt, government pathologist, have shown that the disease known as “Red Water,” in Australia, is iden- tical in its nature with what we call “Texas Fever ;” and that if the inoculations be made with the bloeld “of animals which have recently recovered from the disease, the degree of immunity result- ing from it is suflicient to enable the animal to withstand the dis- ease in its most virulent form. With these facts before us, we have made the following experiments: , EXPERIMENT No. 1. BULLOOK.-—TEN HEAD or ABERDEEN ANGUS BULLS. This experiment was made to ascertain the practical value of inoculation with the blood of an immune Southern animal, to pre- TEXAS FEVER. 73 vent the fatal type of Texas fever. The cattle used consisted of ten Aberdeen-Angus bulls, 6 to 10 months of age, that were raised near Wichita, Kansas. The blood was drawn from the jugular vein of an immune cow in Brazos county, Texas, into a clean sterile vessel. To it wais added 10 per cent. of a saturated watery solution of tri-Kresol, to lessen the danger of putrefactioni The blood was immediately for- warded to Wichita. The inoculations were made by Dr. “far/i on November 19th, 1897, who gave each bull 8 cc. of the blood sub- cutaneously. After inoculation, the bulls were kept as quietly as possible in a lot during the day and in a warm barn at night. They were fed prairie hay and a mixture of equal parts of corn chops, oats and bran. p During the fever following the inoculation they showed a marked loss of flesh, but none refused food entirely. They were held in this lot for thirty days, and then shipped to the Brightside ranch in Brazoria county, Texas, where they arrived De- cember 24th, 1897. They were put with Southern cattle, no attempt being made to isolate them. They were grazed on oats and fed cot- ton seed and sorghum hay. 0n January 111th, 1898, one of them died suddenly. A post-mortem examination was made by the man- ager, who attributes the death to “dry murrain.” One or two others were sick but recovered. No other sickness occurred among them during the foillowing summer (1898), and they have grown fairly well. As to the present condition of these cattle, the manager writes: - “In the spring of 1899 they were turned in with the range cattle i-n the big pasture, being at that time 2 years old. They have taken their chances like Southern grown cattle, and have done good ser- vice and look well.” EXPERIMENT No. 2. RHEA.—TEN HEAD on REGISTERED sxromwixoaiss.’ This experiment differs from the preceding in that the inocula- - Lions were made with immune blood after the cattle had been taken south. Lot I consisted of four animals, two bulls about 8 months old, and two heifers about 12 months old. These cattle were pure bred Shorthorns, raised near Council Grove, Kansas. 'l‘lie_y were Slllp- ped south and arrived in Collin county, Texas, in February, 1898. They received subcutaneous injections of defibrinaiterl immune blood, prepared as in the preceding experiment, from a cow in Brazos county, Texas, as follows: The bulls received 4 cc. and the heifers 8 cc. In eight days one of the bulls and oneof the heifers refused their food, became gaunt, showed reeling gait, which con- 74‘ TEXAS AGRICULTURAL EXPERIMENT STATIONS. tinned for some days. They were eating again reasonably well by the expiration of two Weeks. '.I.‘he other bull and other heifer which received the same dose at the same time were not apparently af- feeted. After twenty days the four were inoculated as in the first in- stance. The two that were sickened by the first dose were not ap- parently affected by the second. The other two, on the ninth day refused to eat, anid were stupid for several days. On April 25th, each animal received a third inoculation, of 8 cc. of defibrinated blood; but no effects were apparent from it. Lot 11 consisted of six registered Shorthorns, raised in Cooper county, Missouri. They were shipped to Collin county, Texas, Where they arrived April 21st, 1898. The lot consisted of one bull '7 Registered Short-Horn Heifers at Close of First Season's Exposure in North Texas. Inoculated with Immune Blood. months old and five heifers from 8 to 12 months old. On April 25th each one received 4 cc. of defibrinated blood subcutaneously. » This blood, as in the former experiment, had been prepared at the Texas Experiment Station, from an immune cow. Eight d-(tys later four of the calves left their food untouched, but no other symptoms of an alarming character developed. May 25th, 1898, each calf received. a second inoculation of de- fibrinated blood of 4 cc. subcutaneously. Eight days later they all showed a lack of relish for their food, which continued three or four days. Nothing further was noticed until September 10th, 1898, when one of the heifers of lot 1 died. All of the remaining heifers produced good, healthy calves in the spring of 1899, and have all passed the summer of 1899 successfully, though they have been very ticky and have perhaps suffered from them. TEXAS FEVER. 75 EXPERIMENT No. 3. GREEN .-—ONE HUNDRED AND THIRTY-SIX HEAD OF REGISTERED SHORTHORNS. Lotgl consisted of ninety-four pure bred Shorthorns, whose ages ranged from 6 to 12 months. They were raised in New York, Ohio, Indiana, Illinois and Iowa, and had been bunchedon the owner’s farm in Ooles county, Ill. October 15th, 1898, each received 2.5 cc. of defibrinated blood subcutaneously. The blood used was from a 6-year-old ox which had bOODJ raised in Southern Texas and had been brought to Illi-nois in September, 1898. October 29th (fourteenth day) .——The smallest calves seem to be sick. Five or six have been stupid two or three days, and half of the bunch show symptoms of fever. The largest ones are not aifected apparently. November 2nd (seventeenth day).—One of the calves died yes- terday (sixteenth day). Two are very sick; others are in various stages. Nearly all are discharging mucous from the nose and mouth. They show staring coat, drawn and pinched appearance, drooping ears, panting, stiffness of the limbs, glassy eyes. In many the catarrhal symptoms, labored breathing and Weakness are severe. November 4th (nineteenth day).—No local "trace of. inoculation on any of the calves. Two of the smallest are sick. Some are get- ting better and some are just taking sick. The heifers seem to be less severely aifected than the bulls. The most pronounced symp- toms are drooping ears, nasal discharge which is bloody in some eases, rapid breathing, staggering gait; loss of appetite and flesh, pinched, drawn appearance of the whole body. Lot 11.—November filth-Inoculated forty-three more calves from Iowa, that have arrived since October 15th, giving each 2.5 cc. of blood taken from the mate to the ox whose blood was used on October 15th. Also reinioculated six of the first lot which showed no marked symptoms, using 2.5 co. of the same blood as lot ‘No. II. The majority oi the cattle are doing well, about twenty appear gaunt, but the most of them are eating well. One young bull re- fuses food and appears very sick. November 10th.—The young bull that has been so sick, died last night. November 19th.—On‘e calf of lot II is very sick (tenth day.) November 28th (fortjy-third day).—The sick calf of lot I, which had a relapse (second reaction) is about well. December 3rd (forty-ninth day).—'I‘he calves are doing very well. Feeding them corn, oats, bran and hay’, and turn them into 76 TEXAS AGRICULTURAL EXPERIMENT STATIONS. the pasture on pleasant days. The second lot have not been so sick as at first. Some of the first have had relapse (second reaction). Three of the six which were reinoculated have shown the effects of it. All are in thriving condition except two or three of lot I. The probable cause of the cattle of the first lot not doing so well as the second is that they were exposed to a cold rain storm about the time of t11e primary fever period. December 18th.—Cattle shipped south. December 20th.—Cattle fed at Parsons, Kansas. December 23rd.—'l‘rain wrecked at Marques, Texas, at midnight. One car turned over. Ten calves killed outright and many crip- pied. December 24th.—Cattle arrive at San Antonio, Texas, and are put in yard. They appear badly fatigued and gaunt from long journey and shake up of wreck. Many of them have pink-eye. January 17th, 1899.—Cattle have been moved to the ranch in Dimmit county. Four or five have died of black-leg. Otherwise they are doing nicely. August 23rd.—No losses from fever among inoculated cattle up to July 10th. Not many ticks on them until then. Since that date have lost ten which were inoculated, and ten others have been sick but have recovered. They had been fed grain and hay or cane until June 1st, when grass was so abundant that they preferred it. They were doing as well as one could wish until July 10th. One red poll bull, which has carried ticks all spring amd summer has shown no signs of fever to date. September 20th.——Cattle all doing well. Have lost about ~10 per cent. of those that were not inoculated. EXPERIMENT No. 4. Toor-Trunrv HEAD or nnersrnnnn HEREFORD BULLS. This lot of bulls, consisting of thirty head off registered Here- fords, bred in Missouri and Illinois, was supplied by Captain John Tod, manager of the Laureles ranch, Corpus Christi, Texas. On their arrival at the Missouri‘ Station, November 1st, 1898, they varied in weight from about 2'75 pounds to 850 pounds. 'l.‘he weights of each at the beginning and end of the experiment, with gain or loss, are given at the head of the temperature tables. le- fore inoculating the bulls, they were given a weeks’ rest, to allow them to overcome the soreness and fatigue incident to shipment, changes of food and surroundings. On November 7th,¢fourteen head of the small and medium sized bulls were inoculated, each receiving subcutaneously 2.5 cc. defi- H TEXAS FEVER. 7 1 brinated blood from an immune Texas steer.* This lot of bulls is designated in: the temperature tables as “Group I,” and consisted of animals numbered as follows: Nos. 1,3, 2, 13,7, 14, 17, 12, 19, 15, 26, 4, 21 and 18. Bulls Nos. 4-, 21 and 18 were reinoculated De- cember 8th with 2.5 cc. of defibrinated blood from a “recovered” native. _ On November 15th ten more head were inoculated "from the Texas steer, 2.5 cc. blood being given. In this lot was included one of the larger bulls (No.23) weighing 680 pounds. In the temperature table this lot appears as Group II. The lot comprises bulls Nos. 8, 22, 20, 23, 24, 16, 10, 28, 25 anad 5. All these ex- cept the first four were reinoculated December 8th, dose cc., from the recovered native. Registered Hereford Bulls on the Laureles Ranch, in South Texas. Inoculated with Immune Blood. The remaining six bulls, Nos. 58, 11, 29, 9, 30 and 6, the larg- est ones of the shipment, were inoculated November 29th, an in- itial dose of 1 cc. being given from the Texas steer, and nine days later (December 8th) a second inoculation, of 2 cc. from the re- covered native was given. No reaction had appeared in this lot up to the time of the reinoculatioin. Most of thebulls that were reinoculated in groups I and II had shown no marked fever from the first inoculation, but a few animals that had shown fever were also reinoculated to determine the effect. ' Clinical notes in addition to the temperature tables, are given *This supply animal W351 received from College Station, Texas, in June, 1898; was one left over from “dipping experiments.” The ani- mal was kept on an infected pasture during the summer and was bearing a few mature ticks at the time the blood was used. 78 TEXAS AGRICULTURAL EXPERIMENT STATIONS. upon each animal. These notes show date of rise of fever, its duration and type, whether severe or mild, the condition of the animal when shipped, and the history of the bulls after shipment south. ~ A study of the temperature notes and records shows that, as a rule, the inoculation fever begins about the eighth or ninth day after the injection, but sometimes a little earlier and sometimes a little later, and that it usually continues from seven to eight days. In some cases it may not exceed more than four days, and in others it may be prolonged to fifteen days. The daily average of the temperature during the primary fever period, counting all that reacted distinctly, was about 104.5. A remarkable feature observed in quite a number of the ani- mals in this experiment was the occurrence of a distinct secondary fever period, beginning at about the twenty-fifth to thirtieth day after inoculation, and continuing from seven to eight days (in a few cases four or five days, and in a few from twelve to sixteen days). This secondary fever appeared to be not so severe as the primary. The graphic records, page 84, illustrate this matter of the primary and secondary fever periods. In some animals that received but one inoculation, no appreciable reaction appeared at the usual period of primary fever, but came up strongly at the secondary pGTiOdL These bulls were not kept under observation a sufficient length of time to determine whether a regular “periodi- city” occurs in this fever, as in malaria (the micro-organism of A which appears to be nearly related to~that of Texas fever). The suggestion arises that tertiary and succeeding recurrences of fever take place, each milder than the preceding, u-nitil finally immunity is attained. The matter of the occurrence of the marked secondary fever period has been confirmed in experiment No. 8, carried on during the succeeding summer at the Texas Experiment Station. In this latter experiment five animals were used; the temperature records were taken twice daily and in a more systematic manner than in the larger group of the above experiment. In addition, regular determinations of the decrease and increase of blood corpuscles during the experiment were made. The temperature records and clinical notes are given of each animal of this lot. These data give a more accurate knowledge of the effects of inoculation upon cattle of different ages than are supplied by the preceding experi- ments, of which we had no opportunity to make a close study. -w "o TEXAS FEVER. CLINICAL NOTES ON THE TOD BULLS. Group I. Inoculated November 7, 1898; dose 2.5 cc. each. Shipped to Corpus Christi, Texas, January 1, 1899. Arrived at destination January 6th, 1899. Bull No. 1.—Weight when received 272 pounds; gain in sixty days, 38 pounds. High fever on eighth day, continued from 105 to 106 F. for five days, with slighter fever for a few days longer. The maximum temperature during this period was 106.4 F. On the thirty-third day began a secondary fever period which continued four days. The temperature was about 104 during this period. Calf ate but little during the acute stage of the primary fever, was very sick, urine highly colored from urates; found- no haemaglobin in the urine. Fell off in flesh considerably, but ate well and improved in condition after the acute stage of the fever had passed. In fair conditiion when shipped. January 9th, third day after arrival, temperature 103.2. Died from snake bite May 28th; had carried ticks since February. Bull No. 3.——Weight when received 285 pounds; gain in sixty days, 25 pounds. Had fever on ninth day; continued four days, temperature ranging from 104 to 106 F. Secondary fever arose on the thirty-fourth day, continued four days, 104 to 105.9 F. Fell off some in flesh, but ate well and improved in condition. Shipped in fair condition. June 24th, temperature 102, carrying ticks. August 14th, having carried ticks through spring and summer, has shown no serious illness, is alive and in good health. Bull No. 2.—Weight 300 pounds when received; loss during experi- ments, 10 pounds. Primary fever began on eighth day, continued eleven days, 104 to 105.7 F. Was free from fever about thirteen days. Secondary fever period began on the thirty-third day and continued a week. at 104 to 105.8 F., was off feed at height of fever; got thin and suffered from cold, although well protected; in a barn.’ Was in poor condition when shipped. Calf appeared to be affected with “Hoose,” had husky cough when brought to Missouri Experiment Station. January 9th, temperature 104. June 24th, temperature 104; has some ticks. This bull died in the summer. From the description given the death was probably due to “Hoose,” or lung worms.. Norm-The above three calves had just been weaned before being sent to the Station, and were not in proper condition for inoculation. Bull No. 13.—Weight 382 pounds when inoculated; gained 18 pounds. Fever- appeared on ninth day and continued ten days. 103.9 to 108.4 F. A slight secondary fever the thirty-third day, continued four days; 103 to 104 F. During height of primary fever was off feed and dull, head drooped. After fever had passed he ate while at the Station. Was shipped in flair condition. January 9th, third day after arrival in Texas, temperature 104. January 11th, appeared well; was found infested with ticks early in February; no fever. April 24th, no sickness since recovery from the shipping fever. June 24th, temperature 104; has a few ticks, urine clear. July 22nd, doing well. August 14th, doing well. Bull No. 7.—Weight when inoculated 390 pounds; no gain. Fever on eighth day; continued four days, 104 to 105.8 F. An occasional high temperature from twelfth to thirtieth day. Secondary fever twenty-ninth to thirty-fifth day, 103.4 to 105.2 F. Did not thrive. fell off in flesh; somewhat thin when shipped. Temperature was not taken at Corpus Christi; condition not mentioned. Became infested with ticks in February; no sickness apparent. April 24th, has ‘done well. June 24th, temperature 102.4, and is extremely “ticky;” no depression apparent. August 15th, in good health. 80 A TEXAS AGRICULTURAL EXPERIMENT STATIONS. Bull No. 14.——Weight when inoculated 390 pounds; gained 10 pounds. Fever on tenth day, continued six days, 103.8 to 104.4. Slight recur- rence on twenty-fifth to twenty-seventh days. Animal ate well and showed outwardly but little signs of fever. . Shipped in fair condition. January 9th, temperature on third day after unloading in Texas was normal, 102 F. Was infested with ticks in February, and has carried more or less through the summer. On June 24th was very ticky, but showed no signs of illness. Temperature 102.4. In May and June was put for a while with heifers. August 15th, is in good health. Bull No. 17.—Weight 410 pounds when inoculated; gain 75 pounds. Fever on eighth day, continued eight days, 104 to 105.5 F. On the fortieth to forty-second, day temperature 104 to 104.7. Bull was off feed and dumpish during primary fever period. Made a good recovery and was shipped in excellent condition. The temperature was normal, 102.1, on the third day after reaching Texas. This animal carried ticks through the summer, but had no fever. June 24th, temperature 101.8; was carrying ticks. Was for a time with heifers in May and June- August 15th, in good health. Bull No. 12.——Weight 412 pounds when received; gain 18 pounds. Had not recovered from shipping fever when inoculated; temperature 104. Had a well marked primary reaction, maximum temperature of 107.4 F. on the tenth day, and fever ten days longer, ranging from 103 to 105 F. Secondary rise, 103.2 to 105.6 from thirty-fourth to thirty-eighth days. This bull was off feed occasionally, but ate well the greater part of the time. Was looking well when shipped. Tem- perature after reaching destination, 103. Has carried ticks since early in February. June 24th, was carrying ticks; temperature 101.4. August 15th, in good health. Did some service in May and June with heifers. Bull No. 19.—Weight 428 pounds. Fever on the fourth day. Con- tinued about; two weeks. 103.4 to 106 F. Slight secondary fever on twenty-ninth and thirtieth days. Made good recovery and was shipped South in fair condition. Ate well most of the time; lost some flesh during fever period, but regained his condition. Temperature normal. ‘102 F., on arrival in Texas. Ticks found on him on February 10th. April 24th, no fever to date. June 24th, temperature 103, very ticky. August 15th, in good health. Did some service in May and June. Bull No. 15.—.-Weight 455 pounds when received; gain, 20 pounds. From fourth to fourteenth day somewhat feverish, 103.5 to 106.4 F. (evening temperatures), but was not off feed. From twenty-third to twenty-seventh day calf appeared dumpish, laid down considerably, ate some, but appetite not good. Morning temperature 104.7 to 106.2; one evening temperature 106.5 F., on a cold stormy day, December 3rd, for twelve days succeeding this fever period, animal did well. A third period of fever began about the thirty-ninth day and continued eight days. 103.6 to 105 F. This calf had some fever when shipped. January 9th, three days after arrival in Texas, temperature 102.6. February 10th, had ticks. April 24th, no sickness to date. June 24th, temperature 103.7; very ticky. August 15th, good health; was with cows and heifers in May and June. - Bull No. 26.—Weight 480 pounds when received; gain 20 pounds. Through the usual primary fever the daily temperature was somewhat irregular, 103 to 104.5 F. Afternoon temperature on tenth day was 106.2. On the nineteenth day had a catarrhal discharge from nose. Was _not ofl! feed, and did not show outwardly any serious symptoms up to the fortieth day, when he appeared dumpish. Had a regular fever period from thirty-ninth to forty-third day. Temperature 103.8 to 106.8 F., the latter on the morning of the forty-second day, at 11 a. m. TEXAS FEVER. 81 Except for a slight running at the nose was in good condition when shipped; was eating well. Temperature on arrival in Texas was about normal. Infested with ticks in February. April 24th, no sickness yet appeared. June 24th, animal ticky, but appeared well. August 15th, bull in good health; has done some service. Bull No. 4.-—Weight 380 pounds when inoculated; gain 45 pounds. Fever on eighth day, continued ten days, 103.4 to 105.8 F. Secondary fever began on the twenty-ninth day and continued eight days, 103.8 to 105.8 F. This bull ate well and except for some falling off in flesh following the fever period, no outward signs of the fever were notice- able, At the time if the shipment the animal was in fair condition. This bull was reinoculated by mistake on December 8th, the third d.ay of the secondary fever period. Temperature on arrival in Texas (102) normal. Has carried ticks during the summer. August 15th, is in good health. Bull No. 21.—Weight 415 pounds when inoculated; gain 30 pounds. Fever on fourth day, continued ten days; ranged from 103.6 to 104.4. Ate well and showed no marked outward signs of illness. Secondary rise on thirty-third day, continued five days, 104 to 104.6 F. Shipped in good condition. This animal was reinoculated December 8th with 2 cc. Temperature on arrival in Texas 103.6, slight fever. Beca.me tick infested in February. April 24th, reported in good health. June 24th, temperature 102.5, and carrying ticks. August 15th, bull is in good health; has done some service. Bull No. 18.—Weight 445 pounds when received; gain 85 pounds. No distinct fever period occurred at the usual time following inocula- tion, only a few isolated high temperatures. On the thirty-first day and for a few days following the temperature was up to 104. The bull at this time was somewhat dumpish and off feed. The animal was reinoculated at the beginning of this fever period. Was sent South in good condition. Had fever on arrival at Corpus Christi, Texas. Temperature January 9th, 104.2. Was off feed a few days—-probably a secondary reaction from the inoculation of December 8th. Animal carried ticks through the summer. June 24th, temperature 103.4, bear- ing ticks. Was put with cows and heifers for a while in May and June. August 15th, is in good health. Group IL-Inoculated November 15th, 1898, with 2.5 cc. defibrinated blood from Texas steer. Shipped to Corpus Christi, Texas, January 1st, 1899, arrived at destination January 6th. Bull No. 8.—Weight 370 pounds when received; gained 10 pounds. Had fever off and on during the sixty days at the Station. From twenty-fifth to thirty-fourth days a somewhat continuous fever, 104 to 105.6 F. Animal looked thin when shipped, although he had made a slight gain in weight. Temperature on arrival in Texas, 103. Carried ticks through the summer; showed no serious illness. August 15th, in good health. Bull No. 22.—Weight 435 pounds when received; gain 90 pounds. Had some fever when inoculated, probably from shipping. On tenth day was dull and off feed, afternoon temperature 106.3. From thirtieth to thirty-third days temperature 104 to 105 F; animal dumpish. The animal did well the greater part of the time, and was shipped in good condition. January 9th, three days after arrival in Texas, tem- perature 103 F. August 15th, in good health; has been well infested with ticks. Bull No. 20.—Weight when received 550 pounds; gained 60 pounds. Scarcely any elevation of temperature until the twenty-ninth day after inoculation. From the twenty-ninth to thirty-seventh days, 103.8 to 104.6 F. Was a little off. but did not refuse food. Did well and was 82 TEXAS AGRICULTURAL EXPERIMENT STATIONS. shipped to Texas January 1st, in good condition. January 9th, tem- perature 103. Reported well April 24th, June 24th and July 22nd. August 15th. is in good health. Has done service. _ Bull No. 23.—-Weight 680 pounds; gained 30 pounds. Fever on the eleventh day, continuing eight days. Temperature ranging from 104 to 107.6 F. Animal was off feed, dumpish, lay down much of the time, and appeared to be extremely sensitive to cold. Had no secon- dary reaction. Made a good recovery, and was shipped in fair condi- tion. Temperature January 9th, 103.2. August 15th, has carried ticks since early in February, and has shown no serious illness. Has done some service. _ Bull No. 24.—Weight 365 pounds; gained 50 pounds. Had no distinct reaction at the primary fever period, but a few isolated high tempera- tures——105.6 F. on the tenth day, 103.8 on the twelfth day. On the thirty-fifth day and following, a more continuous fever occurred, the temperature ranging from 103.7 to 107.1 F. This bull received a second dose of 2.5 cc. defibrinated blood from a recovered native on the twen- ty-third day after the first inoculation. January 9th, temperature 102.6. Was found to be infested with ticks in February. No illness resulted. Was in good health April 24th. June 24th, very ticky, tem- perature 103. No depression; in fair flesh. August 15th, is in good health. Bull No. 16.—Weight when inoculated 402 pounds; gained 88 pounds. This bull was inoculated twice, but during the entire sixty days that he remained at the Station only a few high temperatures were ob- served—on the eighth day, 103.8; seventeenth day, 103.9; twenty-first afternoon, 106; thirty-fourth day, 103.9; fortieth day, 103.6 F. No con- tinuous fever period occurred. This bull ate well and kept in excellent condition. Had some fever on arrival in Texas. 104 F. January 9th. A delayed reaction may have occurred. This animal became very ticky and on June 24th had some fever, 104 F.. but outwardly showed no marked signs of illness, and no depression. August 15th, no illness, was with cows and heifers a part of May and June. - Bull No. 10.——Weight, 480 pounds; gained 105 pounds. Showed but little rise of temperature from the first inoculation. Was reinoculated twenty-three days later (December 8th) with 2.5 cc. blood from a native made immune by artificial tick infestation. A marked fever period followed this second inoculation, beginning on the fifth day and continuing six days or longer. This fever period corresponds to the secondary reaction of the usual type, and it is possible that this may be a delayed response to the first inoculation. January 9th, tempera- ture 101.1; February 10th, had ticks. April 24th, no illness to date. June 24th. July 22nd and August 15th, in good health. Has done some service. Bull No. 28.—Weight when received, 498 pounds: gained 47 pounds. Had an occasional high temperature following the first inoculation, but no sustained fever period. A well marked period of fever followed the second inoculation, averaging 104.2 for nine days. In good condi- tion when shipped. January 9th, temperature 102.6 F. Reported in good health February 10th, though carrying ticks. Also on April 24th, June 24th, July 22nd and August 15th, in good health; has borne ticks. Has done service. Bull.No. 25.—Weight, 507 pounds when received; gained 38 pounds. No fever period occurred at the usual time following the first inocula- tion. but eleven days after the second inoculation the temperature rose to 105 and continued at about this point for five days. January 9th, temperature 102 F. August 15th, has carried ticks through the summer, and has shown no illness. Has done some service. TEXAS FEVER. 83 Bull No. 5.—Weight when received, 600 pounds; gained 80 pounds. Temperature normal for twenty-seven days following the first inocu- lation, except on twelfth day. 104.8 F. Reinoculated on the twenty- third day; five days later a well marked fever period began and con- tinued five days. Temperature 104 to 106.5 F. Was somewhat dump- ish, but continued to eat; was shipped in good condition. January 9th, temperature 102.2. June 24th, 102.2. August 15th, in good health after carrying ticks through the summer, and doing some service. Group IlI.—Inoculated November 29th, 1898, 1 cc.; and December 8th. 1898. 2 cc. v Bull No. 58.——Weight when received 505 pounds; gained 135 pounds. Had shown scarcely any signs of reaction up to the time of shipment, only two high temperatures, 104 F. on the eleventh day after the second inoculation, and 103.8 F. on the seventeenth day. This animal was never off feed. January 9th, temperature 103.6 F., a slight elevation. A secondary reaction of mild type may have occurred at about this time. January 20th, arrived at ranch twenty-five miles from railroad. February 10th, bearing ticks. June 24th, animal well and bearing ticks. August 15th, in good health. Has done some service. Registered Hereford Bulls Inoculated with Immune Blood. Now at Laureles Ranch. Bull No. 11.—Weight when received 620 pounds; gained 110 pounds. Fever arose on the sixth day after first inoculation, and continued for five days, varying from 104.2 to 106.3 F. During fever period was off feed, dumpish, back arched. Made a good recovery and was shipped in excellent condition. January 9th, temperature 103.1 F. Became in- fested with ticks in February. April 24th, no sickness to date. June 24th, carrying ticks; appears well. August 15th, in good health. Has done service. Bull No. 29.—Weight, 715 pounds when inoculated; gained 15 pounds. No fever period had occurred up to the date of shipment, and only one high temperature, 104.1 F. on the twenty-first day after first inocula- tion. This animal had some fever after arrival in Texas. 104.6 on Jan- unary 9th. This fever occurred at about the time for a secondary reaction following the inoculation on December 8th, but possibly may have been simply shipping fever; but did no-t thrive well for some. time. Arrived at ranch safely. February 10th, found ticks. May 13th, turned with cows; found sick June 7th, twenty-five days later; temperature 104. F. Was taken away from cows and kept quiet for a 84 TEXAS AGRICULTURAL EXPERIMENT STATIONS. GRAPHIC Rzcorw or Usu/zl COURSE arFb/En Hllawiue [n/ocul/ITION wiTH IMMUNEBLOOD, ’8”"”°”' 7 7 11 1315 17 11 .11 23161721” 1 a 5 7 <2 11 131x17 11 11 2a 3"?“ /_ 3 5 7 1 1/ 121517171-123 15171921 193243737 41/43 4Y4 106 105' Bull /oq ,4 10a B11 " I04: ~ If 111mm .11 1| H? 105' -, [Z jzinmfiflfiflmln I I UHIIHIHTMV % v 105' F [Aw 7 B1111 m“ ‘ » ‘Tqw J *- $111M WU x1 1 . 105 ‘ _ l 1 1111 2’ 1111111111111 11m 110.5 T ' 1 /05 l i 1oz l I I I - T _ VxflThLV 106‘ *1 22111111111111111111111111111 TEXAS FEVER. 85 couple of weeks and was then turned out to service again, and has kept well ever since. Bull No 9.-—Weight, 795 pouds when received; gained 95 pounds. Fever on thirteenth, fourteenth and fifteenth days following first in- oculation, 103.8 to 105.6 F. Animal kept in good condition, no pro- longed fever period. Shipped to Texas in good condition. Tempera- ture January 9th, 105.8; January 11th 105; appears to be a secondary reaction. from the inoculation. February 25th, had ticks; shows no sickness. April 24th, no sickness to date. August 15th, has carried ticks through the summer and has had considerable service. Bull No. 30.—Weight, 815 pounds; gained 135 pounds. Inoculated November 29th with 1 cc. blood from an immune, Texas steer, and re- inoculated December 8th with 2 cc. from a recovered native. No rise of temperature up to time of shipment. January 9th, three days after reaching Corpus Christi, had temperature of 103.4. Appeared sick on January 11th, temperature 104. This may be a delayed reaction from the inoculation brought out by shipping, or simply shipping fever. Registered HerefordfBulls, Inoculated with Immune Blood. January 20th. arrived at Laureles ranch, driven out twenty-five miles from Corpus Christi. February 10th, found ticks. February 15th, appears sick. February 25th, ticks on this bull, appears Well. April 24th, has done well. May 16th, turned into pasture-with cows. June 3rd, sick; temperature 108 F. 7:30 a. m. June 5th. died of Texas fever, passed red water before death. Post-mortem showed enlarged spleen and red water in bladder. Bull No. (i-Weight when inoculated, 823 pounds; gained 117 pounds before shipping. Had a slight reaction on seventh to tenth days fol- lowing second inoculation; had chill at beginning of attack. Was ofi food and dumpish. Recovered appetite in a few days, was shipped in good condition. This animal had fever on arrival in Corpus Christi; January 9th, temperature 104.6, either from shipping fever or secondary reaction from inoculation. January 20th, arrived at ranch twenty-five 86 TEXAS AGRICULTURAL EXPERIMENT STATIONS. miles from Corpus Christi. February 10th, found ticks. February 15th, this bull was sick. February 25th, has recovered and is carrying ticks; temperature at 4 p. m., 103. April 24th, appears to be free from ticks; no illness observable. May 13th, was put in pasture with cows, was in strong, vigorous condition; had been well infested with ticks. June 4th. died from acute attack of Texas fever. TABLE 2. Temperature Record 0f Group I. Bull Bull Bull Bull Bull Bull Bull R1111 Bull B1111 Bull Bnl1 Rull Bull 1 3 2 13 7 14 17 12 19 15 26 4 21 18 Weight NOV 1 272 285 300 382 390 390 410 412 428 455 480 380 415 445 Weight Jan.1. 310 310 290 400 390 400 485 430 475 475 500 425 445 530 Gain O1‘ LOSS 38 25 —10 18 .. 10 75 18 47 20 20 45 30 85 l NOV. 7.... ..102 103 103 102.5 10281025104 102 5103 102.5103.5 . “ 11. . . . 4 102.9 103.2 103.1 102.8 104 8103 102.9104 104.5 104 5 103.2 103.6104.4101.5 “ 15 8 106 4103.4 105 4103.2 104.8103 2104.2 105.4104 106 4103.3 104 2 104.1103 “ 16 9105 4104 104.4104 104 103 105.2107.2103.8 103 6103 5 104.1 104.2 “ 17....10105 6104 105 6 103.9 105.8 103.8 104 107.4104.1 103.5 106.2 104.5 103 ‘ 18 11106 2 106 103.9106 5104 4104 2105 105 8 105 103.8 103.4104 104 104.1 ‘ 19....12l053lC6 10561084 . 1037104 1073 .. .104 1035 1032 “ 20.. . 13103 5102 4 105 7107 2 103 6 104 104 5103 104.5103 4 104 4103 4103 6103.2 “ 21 14104 Z103 5 105 7104 103 3104 4105 5104 5 104.8104 410.5 71039104 2104.3 “ 23 .. 16 I03 4 103 3 104 6 102 1041103 8104 810491034102 104.4 103 810.2 8 102.6 “ 24 ..171031.....10511U45 ...1028104 .. .. “ 25.... 18 104 102 8104.6 104 8 105 8102 2 102 8 103 106 103 104.2105 8102 1 101.6 “ 26. .. 19 102 I03 104 104 1 103 4103.2 103 4 104 5 102.3102 8 103.5103 8 102 3 103.0 “ 27. . 20 102 2 105 101 101.2 103 4 101.6102 2 10 8 102 102 102 10.’. 2 104 102.4 “ 30 23 103 10.1 5 103.4 104.2 103 5 102 8 105 105 102 10w 103 4 I02 103 2 103 2 D81 2 25 . . 104 5 104.1 103 3103.5 103.8104 7 103 6103 0 103 5104 ‘ . 105 3 .....1033 -. 541020.... 02 10541042102 ~~ 12 s5 104 z 104 010s 4 103.6 104 2 10s s 10s 105 0 1oz 4 102 101.s 105 104 104 > “ 19. . . . 42 103.4 102 4104.4 105.4 103 4 102 4 104.7 103.7 102.4 104.8 106.8 102 8103.1 104 “ 20.... 43102 101 2 103 101.2102 6 101 103 101.6 102 4 104 105 103 104 101.4 ' 32103.8 101.2>101.b 102.6102 6104 l103.2102.7101.6102 “ 22. 45103 104 103.6 101 61104.2 102 4 104 102 102 4 105 102 6 103.8 102 6102.2 “ 25. .. . 48 103.6 102.5 104.5103.8l102 103711034 103.8 102.2104 101.8 102 4 102 3104 TEXAS FEVER. ’ 87 I Temperatzwe Record 0f Group II. Bull Bull Bull Bull Bull Bull Bull Bull Bull Bull 8 22 20 23 24 16 10 28 25 Wt. before Inoculation .. 3701 435 550 680 365 402 480 498 507 600 680 Wt. after Inocuiationm. 380 525 610 710 415 490 585 545 545 Gain 0r loss . . . . . . . .. 10 90 60 30 50 88 105 47 38 80 106 | 103.4 . . . . .. 102.2 103.4 103 3 1036 102 104.6 103.2 104 104 104 104 s: 104' 105 1011011021; 104.6 103.3 105.1 102.6 10412 34 104 103.5 104 4 102.4 103.2 103 9 103.2 104 105 103 35 103 2 103 104.2 103 8 104.2 101.6 104.6 104 4 104.8 103.8 36 101.8 l02.6 104 102.8 103.9 102.2 1037 104 105.8 102.2 37 104 104.2 104 103 4 107.1 101.8 104 105 105 104.3 40 102 8 102.2 103 103 8 103.7 103 6 103.3 103.6 104.9 102 8 41 103.5 . . . . .. 103.3 103 104.2 . . . . . . . . .. .. 103.8 103.2 103 5 flkmperature Record 0f Group III. Bull Bull B1111 Bull Bull B1111 5s | 11 1 29 9 30 6 Weight before Inoculation . . . . . . . . . . . . . . . . . . . . 505 620 715 795 815 823 Weight after Inoculation . . . . . . . . . . . . . . . . . . . . . 640 730 730 890 950 940 Gain or Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 110 15 95 135 117 NOVember 11 . . . . . . . . . . .. .. .. .. , . . . . .. 102.8 102 5 ‘ 102.8 102.9 103 3 " 15 102.2 104 102.3 102.3 105.5 103 101.8 100.5 102.2 100.4 102.9 101.3 101 102 2 101.2 100.8 101.9 102 2 102.5 102 103 5 102.2 100.5 102.3 101.8 102.3 102.1 103.6 105 103 101 9 102.4 103 103 102.8 103.4 103 102.2 102.2 102 5 102.6 101.8 99.5 101 100.4 102 100.9 101.6 101.2 101 102.4 102 101.7 103.2 102 101.8 101.8 101.2 99.6 100 5 101.4 106. 3 103 102.6 103 101.3 106.1 . . 88 TEXAS AGRICULTURAL EXPERIMENT STATIONS. EXPERIMENT NO. 5. WASKOM—THREE HEAD OF REGISTERED HEREFORD BULLS. This lot consisted of three pure bred Hereford bulls that were raised in Missouri. N01. 534 was 2-year-old and Weighed 1.252 pounds. No. 540 weighed 1100 pounds. No. 3 weighed 550 pounds. They arrived at the Missouri Experiment Station Decem- ber 3, 1898, and were held until the effects of the inoculation had passed ofi, before sending them south. The experiment is of in- terest on account of the age of two of the individuals. The first inoculation was made December 8th. Each bull rc- Registered Hereford Bull No. 534; Weight I252. Inoculated with Immune Blood. Now in Harrison County, Texas. ceived 2 1-2 cc. of recovered blood from a steer that had been ren- dered immune to Texas fever by artificial tick infestations. Bull 534 took sick on the twelfth day following. On the thir- teenth day the fever was 105.2. The fever continued, thorugh not so high, until the eighteenth day, after which the temperature fell to the normal. During the fever the bull was off feed, gaunt and laid down the most of the time. Bull 540—Fever appeared on the thirteenth day, with a maxi- mum of104.8. It was of short duration; he continued eating and appeared to be not seriously sick. Bull No. 3——Fever appeared on the sixth day, and reached 104.3, TEXAS FEVER. 89 and continued six days, after which it fell and the animal’s ap- petite returned. The second inoculation was made January 2d, 1899. Each bull received 2 1-2 cc. of blood from a steer which had been raised in Texas. Bull 534 showed only a mild reaction from this inoculation. It is likely that it was really the secondary reaction from the first inoculation. Bull 540 showed fever on the fourth day. January 6th, fever 105.4 ; bull lies down much. January 7th, 106; bull oif feed. January 8th, 103.7 ; won’t eat. January 9th, 101.5 g eat hay only. January 12th, temperature 100, eats quite well. From this time the bull remained in good health. ~ Bull No. 3—Severe fever followed in this bull. January 7th, bull appears to have a chill. January 12th, fever 1.03.8. January 13th, fever 105.6 5, bull oil’ feed and has diarrhoea. January 14th, fever 104.6. January 15th, fever 104.5 ; urine clear. January 16th, fever.105.8. January 17th, 104.5 at 3 p. m. January 18th, fever 104.6 ; bull eating. January 19th, 104.8. January 21, ' 103.5 ; fever falling. From this time on this bull appeared quite well. During his stay at the Station he gained 65 pounds in weight. _ A third inoculation was given to these bulls. Each received 3 cc. of immune blood from a Texas steer on February 22d. The bulls were shipped south February 25th. They arrived in good condition at the ranch in Harrison county, Texas, March 2d. CLINICAL NOTES AFTER SHIPMENT. March 28th.——The bulls are in a fine condition. Found one tick on Nos. 534 and 540. None on No. 3. Feed them rran and oats twice a day, and allow them to run on a good pasture. April 3rd.——The bulls run daily with our native cattle. They are apparently well. April 10th.—-The bulls appear healthy. Found six ticks on Nos. 534 and 540. No ticks on No. 3. The bulls run freely with native cattle, but are housed and fed at night. April 24th.—The bulls are doing well. But "few ticks have been on them. May 30th.——The bulls appear in good health. June 14th.—-Bulls well infested with ticks. No. 534 has fever. tem- perature 104.5; gave salts. No. 540 has fever, temperature 106.5; gave salts. No. 3 has no fever. Well infested with ticks. June 1.6th.-~-Bulls recovering. No. 534, fever falling, temperature 102.5. (lesires food.‘ No. 540, fever falling, temperature 104.5, appears better. No. 3. no fever, appears normal. June 18th.—Bu1ls all doing well. No. 3 has no signs of fever. June 19th.——Bu1ls appear well. July, no report on theibulls. August 18th.—Bu1ls running with native cows. They all appear well. No. 3 has never shown any signs of fever. 90 TEXAS AGRICULTURAL EXPERIMENT STATIONS. EXPERIMENT NO. 6. OVERALL-——‘EIGHTY-FOUR HEAD OF REGISTERED HEREFORD BULLS. This lot consisted of eighty-four head of Registered Hereford bulls, all of which were natives of Missouri. Their ages ranged from '7 to l2 months. They had been shipped in the cars during very rough weather. So, when they arrived at the ranch in Cole- man county, TeXas, they were very tired and drawn. They were fed cotton seed, which caused a considerable number 01f them. to have scours. On December 22d, 1898, they were inoculated with defibrinated blood drawn from the jugular vein of a 2-year-old steer, bred and raised on the ranch. Sixty-four were given l cc. of the blood and the remaining twenty were given 2 cc. of the blood. These calves began getting sick in the usual time after inoculation (about ten day's), and about one-half of them were severely affected. Three of the number died. At this time the manager noticed that many of them had ticks on them. By April 24th, six of them had died, and the whole lot showed sickness. About June 1st they ivere turned into a "large pasture of 30,000 acres, among the range cattle, and have remained there the whole summer. The owner says they are doing very nicely (August 15th, 1899'), and up to this time seven have died of fever. -Six have died of black leg, and one frorm accident. He says that in his opinion they should have been kept up in a dry lot until the inoculation fever was over before exposing them to the ticks. EXPERIMENT NO 7. BITRGESS——SIXTY—EIGHT HEAD 0F REGISTERED SHORTHORNS. This lot consisted of sixty-eight pure bred Shorthorns, whose ages ranged from 8 to 12 months. They had been raised in Kentucky, and had arrived at the Blue Mound Ranch in Wise county, Texas, November 24th, 1898. On January 4th, 1899, each one received subcutaneously 1. cc. of defibrinated blood from the jugular vein of a 2-year-old steer that had been. raised on the ranch. The owner of these cattle reports (in substance), under date of March 4th, 1899, that four of the calves have died and that the remainder have become reduced in flesh, but‘ appear healthy otherwise. About June fever appeared among them and about cine-half of them showed severe symptoms; by July 24th twelve have died in all. TEXAS FEVER. 91 EXPERIMENT NO. 8. SUBER——SIX HEAD. This lot consisted of one pure bred Shorthorn bull and five graded Shorthorn heifers. They were about ten months of age, and-were raised in Cooper and Boone counties, Missouri. They were shipped south by rail and arrived on the grounds of the Texas Experiment Station in good condition on January 1st, 1899. On January 7th, each received subcutaneously 1 cc. of defibrin- ated immune blood, from the jugular vein of a grade Shorthorn cow on which were a considerable number of ticks (B. bovis) in various stages of development. The calves were kept in a dry lot, in which there were no ticks, and were not allowed to come in con- tact with Texas cattle, or tick infested grounds until April 11th. Grade Shorthorn-Hereford Heifers. Inoculated three times with Immune Blood; Described in Experiment No. 8. Now in Brazos County, Texas. They were examined regularly and carefully for ticks. In doing this each one was turned on its back to allow a thorough examina- tion. All the heifers had white skin along the belly, so that it was exceedingly improbable that any ticks were attached to them and escaped notice, until they were sent to the pasture in April. Their diet had consisted of hay, ground corn, oats and bran. This was gradually changed to cotton seed meal, bran and oats and cotton hulls. They were fed regularly all they would eab. From the first day, January 7th, until August 31st, their temperature was taken daily, and the record appears in this report. The changes in the blood were determined by the ‘hzematokritf’ The blood was ex- 92 TEXAS AGRICULTURAL EXPERIMENT STATIONS. amined two times per week. A gap occurs in the record, from March 22d to April 17th, on account of an accident to the appar- atus. All of the samples of blood for examination were taken from ear, and, as soon as possible, they were subjected to a very rapid centrifugal action. By comparison with other cattle’s blood, we may regard the normal percentage of red blood corpuscles to be from 35 per cent. to 4O per cent. No effects of the inoculation, either local or systemic, were noticed until January 14th, eight days after inoculation, when the haematokrit readings indicated a de- struction of the blood corpuscles. At the beginning of the experi- ment the average per cent of red corpu.scles in the blood was 38.3 per cent. On the eighth day of the experiment it had fallen to an average of 31.3 per cent. The increase in temperature was very abrupt, rapid and almost simultaneous. It appeared on the ninth and ‘mg-nth days after inoculation. We call this the primary fever part0 . The fever ranged from 103.6 the lowest, to 105.6 the high- est; in the mornings. This continued from seven to nine days and then returned to normal. The destruction of the blood corpuscles continued until the thirteenth day of the experiment, the average was 27.3 per cent; on the fifteenth day it was 23.3 per cent. By the nineteenth day (January 25th), the fever had ceased, and the blood gained a little, reading an average of 24.5 per cent. The symptoms of digestive disorder are worthy of mention. During the fever we noticed a lack of relish, though they con- tinued eating. The well ones crowded the sick ones aside. If the sick ones be fed separately, they Wlll consume a reasonable amount. We noticed among some calves bloating, and a disposi- tion to eat a quantity Olf dirt. In some cases there was diarrhoea, and. discharge of mucus from the nostrils, muscular weakness, trembling, and a desire to lie down for a considerable period. In no case was bloody or red urine noticed. By the eighteenth day, the fever of the primary reaction had entirely ceased. We some- times noticed even sub-normal temperatures. One individual had a temperature of 100.8 on the twenty-second day (January 28th). The lowest average per cent of blood corpusoles resulting from the primary reaction was 23.1 per cent., which occurred on the fifteenth day. From the eighteenth to the twenty-ninth day the calves ap- peared normal. Their appetite improved, their blood cocrpuscles increased in numbers. By the twenty-fifth day the average per cent had risen to 31. The secondary fever period began on the twenty-eighth or twen- ty-ninth day. It greatly resembled the primary one in its sever- ity, but differed from it in continuing longer, and in appearing in some animals on the twenty-eighth or twenty-ninth day, while in TEXAS FEVER. 93 others it appeared on the thirty-fourth or thirty-fifth day. The haematokrit readings also show a second fal.l in the blood corpus- cles. This reached its lowest average (21 per cent.) on the twen- ty-ninth day. The lowest inidivdual. on that day was 14 per cent., the highest 26 per cent. The secondary reaction must be regarded as due to the activity of the micro-organism in the blood, and not to a reinfection from without. Every calf was examined with great care for ticks until the ninetieth day, but none were found. The secondary fever period did not terminate so abruptly as the primary, but showed a tendency to an occasional high tempera- ture. For instance, we found No. 3 with a temperature of 105 on the morning of the forty-seventh day, and No. 1 with 1031.5 on the fifty-fourth day, and No. 4 with 103.8 on the fifty-ninth day. While these subsequent temperatures are interesting and very sug- gestive, we may say they were not of any practical importance. The calves gained in weight and growth, and their blood showed some improvement, which was slow but steady. Second Inoculattorw-“Pwo cc. of defibrinated blood was given on the seventy-seventh day (March 23d) subcutaneously to all except N o. 4. This produced a mild reaction in about eleven days; the highest morning temperature was 104 1. Calf No. 4 was not given the second dose of 2 cc. with the others and showed a morning tem- perature of 104.2 on the ninety-fourth day, which was near the same time the other calves were reacting from second inoculation. No record of blood changes was possible because the haematokrit was out of order at that time. The first re-examination of the blood occurred on the 106th day (April 20th), at which time the average was 33.5.». The lowest average reading found since that time was 30.5 per cent., which occurred on the 113th and 120th davs. A third i~n0cuZati0n was made on May 18th, the 132d day. This consisted of 2 cc. of immune defibrinated blood given subcutan- eously to Nos. 1, 2, 3 and 5. No. 4 received 1 cc. of the same material. (No. 6 had died of blackleg on April 10th.) The re- action from this was very feeble. The highest morning tempera- tures noticed were: Nor. 1, May 28th, 102; No. 2, May 20th and 23d, 103.3; No. 3, May 25th, 103.4; N0. 4, May 25th, 105.2; No. 5, May 28th, 103 degrees. . It appears from this that No. 4 showed some reaction, but it was of short duration. The others may be regarded as a very feeble reaction, if any. The haematokrit readings do not indicate any appreciable blood destruction, so that we may regard the third injection as producing no effect, and assume that immunity has been attained. These cattle were placed in the pasture April 11th. It remains to be shown that they were exposed to infec- tion. They were frequently oxaniiuted for ticks and at once be- 9* TEXAS LGRIOULTUBLL EXPERIMENT STATIONS. came infested with the lone star variety (Amblyomma unilpun- tata), which do not concern us in this report. The cattle were infested with young ticks (B. bovis) , on May 5th, May 6th and May 27th. During June and July they car- ried and matured a few ticks of this species. It was not until August that any considerable number of ticks were carried. There di.d not seem t0 be any constitutional disturbance due to their presence, as shown either by the thermometer or by haematokrit examinations of the blood. The experiment closed August 31, 1899. There was no fever among the cattle, nor had there been any. The average per cent of red corpuscles was 33.4 at that time. TABLE 3. Hoematokmt Record of Blood Changes. Eocpemment No. 8. Date 9gb“ No. 1 No. 2 No. 3 No. 4|‘No. 5 No. s Ave. January 7- 1 First Inoculation-l cc. Blood. “ 10 . 4 40 40 35 40 35 40 33.3 “ 14 s 33 33 30 29 33 30 31.3 “ 19 13 31 . 21 33 25 2s 29 27.3 “ 21 15 27 27 19 2s 20 1s 23.1 " 25.. 19 24 29 21 23 2s 24 m5 " 2s. . _ 22 32 21 29 2s 29 2s 2s.s " 31 25 3s 29 2s 31 33 27 31 February 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 30 28 27 26 29 27 27 .8 " 6 .......................... . . 31 36 29 1s 2s 32 21 2s.3 -* ..._ ....................... .. 34 2s 34 1s ls 24 2s 24.3 " 14 .......................... . . 39 21 24 19 22 2s 14 21 “ 1s. ........................ .. 43 23 19 26 23 21 19 2l.s ' 21 .......................... .. 46 25 2o 23 19 23 24 22.3 * 25 ......................... .. 50 23 2s 24 21 3o 2s 25 s " 2s. 53 1s 22 24 21 25 2s 22.6 March 4 ............................ .. 51 19 2s 29 2s 26 24 25.3 " 7 ......................... .. 60 20 2s 20 24 21 22 8 ~~ 11 ............................ .. 64 30 23 34 24 2s 22 26.1 " 14 ............................ .. 67 26 22 29 21 21 25.5 " ls ............................ .. 71 ' 22 27 32 20 32 25 23.3 " 21 ........................... . . 74 30 22 33 24 21 22 26-3 " 2-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 77 Second_Inoculation—2 cc. Blood. April 22 ........................... .. 106 32 33 35 33 35 .... .. 33.5 ~~ 9 ............................ .. 113 32 30 29 31 .... .. 30.5 May s ............................... .. 120 35 29 25 29 .... .. 30.5 " 13 .............................. .. 121 37 21 21 32 31.8 “ 18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 132 Third Inoculation—2 cc ;Blood. * 20 ............................. .. 134 36 43 2s .... .. 33 " 27 ............................... .. 141 33 32 34 35 29 .... .. 32.6 June 3 14s 34 31 40 21 34 .... .. 33.2 " 10 ............................. . . 155 30 30 40 2s 37 .... . . 33 " .............................. .. 162 31 32 3s 31 30 .... .. 33.6 “ - ............................. . . 1119 42 3s 3s 32 31 .... . . 35 .s July 1 ........................... .. 116 43 32 40 31 35.2 " s ............................. .. 193 40 33 3s 30 29 33 6 “ 15 ............................ .. 190 40 31 30 3o 32 .... .. 34.2 “ 2 .............................. .. 197 36 31 29 32 33 “ 29 .............................. .. 204 39 32 3s 2s 30 .. 33.2 August 5 .......................... .. 212 3s 32 30 31 .... .. 33 ' 1 ......................... .. 21s 37 31 3s 27 3s .... .. 35 " 19 .................... .. 225 36 33 39 26 34 .... .. 33.5 " 2s .......................... .. 232 30 34 1 3s 32 33 .... H1 “ 31 .......................... .. 237 35 32 31 30 33 .... I!‘ 33 4 Experiment closed. TEXAS FEVER. Llkmperature Record of Animals in Experiment N0. 8. 95 N0. 2 No. 1 No. 4 101.6 - 10 .8 -. 10.1 . . . . . . .. . 102-6. 103 l03.4 105.2 103.4 105.2 102.4 102.1 103.1 103.4 103.1 104.1 105 105.4 102.4 105.3 103.7 102,6 104 104.4 104.9 105.1 102.4 103.6 105.6 102 103.6 103.6 105 105.2 104.6 104.2 104 103 102.6 102.4 104.8 104 104 104.9 103 105 2.8 103 104.3 104 104.1 104.8 104.8 103 102.2 102.4 102.4 103 103.4 104.8 104.6 103.6 102.2 102.6 104 102.8 103.5 105 104 104 102.2 103.2 102.4 103.4 103.2 103.4 103.5 104.2 101.6 103.3 101.5 104 103.5 104.2 102.6 104.4 102 103 101.8 103.4 102.4 104 102.1 104.3 101.7 103.8 102.5 104 102.4 104.4 101.8 103.8 101.7 103.8 102.6 104 100.8 104 101.4 102.8 102.4 102.4 101.7 103.2 102.1 103.2 101.8 103.9 105 105.2 102.1 103.2 102.4 103.8 101.5 103.6 103 104 101.1 103.1 101 102.2 101.7 102.2 103 102.8 101.7 102.2 101.4 101.8 101.5 102.2 102.8 103 102.4 103 102.5 103 103.2 103 101.4 102.1 103 103.4 101.7 102 102.1 103.3 101.3 102.1 102 103.8 101.8 102.9 101.4 103.8 101.3 102.7 102.1 103.8 101.7 103.9 101 103.2 101 102.2 102.6 103.4 101.9 103 101.2 103.3 102 102.5 102.4 104 101.8 103 102.3 103.2 102 102.8 102.5 103.2 101.4 102.7 102.1 103.9 102.9 103 101.7 103.2 101.2 102.1 101.4 103.8 102.2 102.9 101.5 104.2 101.3 102.8 102.4 103.5 101.2 102 103.8 104.3 101.6 102 102.2 103.4 101.2 102 102.8 104.2 102 102.7 102.2 102.2 101.2 102 101.7 103.2 101.6 102.3 101.9 104 102 102.6 102.2 104.7 103.2 103.2 102.1 104.6 102.3 102.5 101.6 103 102.4 102.9 102.3 104.9 101.7 103.4 101.9 3 101.9 102.9 102 103.1 101.9 102.6 102.2 102.8 102.1 103.1 102.2 102.7 102.5 103.1 102.7 103.2 102.2 102 101.2 102 101.5 102 102.4 102.8 02 102.5 102 102.2 101.3 102 102 102.6 1018 102.5 101.7 102.3 101.4 102.3 101.8 102.8 101.4 102 101.9 103.5 101 102.2 101.9 103.5 101.7 101.8 101.8 103.4 101.4 103 102.2 103 102 102.7 1021 103 100.3 101.2 102.2 103.5 102.4 102.5 03 96 Tmus 46121001301141. nxrnnuumzw 311210123. Temperature Record 0f Animals in Experiment N0. 8.—C0n. Date No.1 No. 2 No. 3 No. 4 No. 5 No.6 1. . *- 31 ...... .. 101.1 102 1014 1024 1012 102 1112 1026 1017 1029 102 1034 Apr.1 ...... .. 101.6 1032 1016 102.9 1021 102.6 1006 1031 1014 1026 1013 1023 2 ...... .. 1012 103 101 103 1013 1032 1006 1023 1015 1024 101 103.3 ~~ 3 ...... .. 101.5 1022 1024 1025 1026 102.1 102.1 102s 1016 1023 101 1024 *~ 4 ...... .. 101.3 1024 1013 1035 1003 1022 100.4 103 1002 102 1012 1027 *1 5 ...... .. 101.6 103 103 1036 102s 102.2 1021 102s 1019 103 102 1021 *1 6 ...... .. 102.5 1026 103 1033 101s 101.3 1024 102s 102: 1022 1026 1020 *1 7 ...... .. 10 .1 . - . . . 103 . -- 23 ...... .. 101.6 102.3 103.3 103.1 102s 1032 ~~ 24 ...... .. 101.1 1034 101.4 1044 101.51 13.6 ~ 23 ...... .. 101.6 102s 102s. 103.3 103.41 103 . ~ 26 ...... .. 102.2 103 102.11 103.2‘ 102.3. 103.1 i -. 1 1 .... .. -~ 21 ...... .. 101.3 1022 102.1 102.61 102.3‘ 1113 1 102.41 103 102.61 102s ........... .. ~~ 2s ...... .. 102 102.4 102.6; 103.4‘ 102.6. 103 1 102.41 103.6 103 1 1036 .... .... .. *1 22 ...... .. 101.6 103 102.2 103 1 102.21 102.3: 102.6 102.s_ 102.41 103.4 . . . . . . . . . . .. *- 30 ...... .. 102 103.6. 102s 1034 102.4: 102.01 102.6 103.61 102.41, 103.3 . . . . . . . . . . .. TEXAS FEVER- 97 Zkmperature Record of A11 imals in Ewpewlqzzent N0. 8. ——C0n. Date No.2 No.3 No.4 No.5 No.6 ilyL RM. A P.M. 31w; P.M. AM. LP. . 1.11. 102-6 103.1 ]O§3.4 102.6 103 103.2 102 $102.5 . . . . . . . . . . H .2 104 1 103.6 102 6 ' 102 4‘ 103 I 98 TEXAS AGRICULTURAL EXPERIMENT STATIONS. Temperature Record of Animals in Experiment N0. 8.—C0n. Date No. 1 No. 2 No. 3 No. 4 N0. 5 N0. 6 1899 A.M. PM AM PM A.M. PM A.M.|1>M AM PM AM PM Augll . . . . . . .. 102.4 1034 101 6 103.1 102 1028 1026 102.8 101 8 1026 . . . . . . . . . . .. ' . . . . . . .. 101.8 034 102 103 101.6 1031 1028 103 1016 1028 . . . . . . . . . . .. “ 13 . . . . . . .. 102 1038 1018 1038 1016102610241044 1022 1026 . . . . . . . . . . .. “ 14 . . . . . . .. 101310381021 1034101410351022104610211038 . . . . . . . . . . .. “ 15 . . . . . . ..101710411016104z102 10331032104410221038 . . . . . . . . . . .. “ 16 . . . . . . .. 101 8 103 1014 1032 101 103 1016 1024 1032 1052 . . . . . . . . . . .. “ 17 . . . . . . .. 1023 103 1022 1032 101.8 102.8 102 1034 103 103 1 . . . . . . . . . . .. “ 18 . . . . . . .. 101 4 103 101 1032 101.1 103.8 101 8 1048 1026 1041 . . . . . . . . . . .. " 19 . . . . . . .. 1014 1036 101 6 1032 101.4 103 102 7 1036 1032 1052 ‘ 20 . . . . . . .. 102 1026 101 8 1038 101.2 103.2 1021 104 1024 1052 “ 21 . . . . . . .. 102 4 103 1022 102 8 101.4 102.6 1024 1032 103 “ 22 . . . . . . .. 1024 1032 1027 1027 101.5 102.6 1025 1023 1024 1034 " 23 . . . . . . .. 1026 1037 102 1035 101.3 103.4 1019 1031 1025 “ 24 . . . . . . .. 1022 1032 1021 1031 101.6 102.6 1016 1024 1024 1034 “ 25 . . . . . . .. 1022 1037 1024 1028 102.3 102.7 1021 1036 1024 1033 “ 2b . . . . . . .. 1022 1033 1018 1025 101.4 102.6 102 1026 1018 1038 . . . . . . . . . . .. “ 27 . . . . . . .. 101 3 1036 101 4 103 8 100.7 102.4 1024 104 101 5 1032 . . . . . . . . . . .. ‘ 28 . . . . . . .. 103 1021 1027 101.7 102.7 1022 1036 1023 1025 . . . . . . . . . . .. “ 29 . . . . . . .. 1024 1033 102 103 101.8 103.4 1033 1032 1017 103 . . . . . . . . . . .. “ 30 . . . . . . .. 1021 103 102 103.2 1022 1031 102.2 1031 1017 1034 . . . . . . . . . . .. “ 31 . . . . . . .. 102 1032 101 8 103.1 101.6 1028 102.4 1034 1021 1036 . . . . . . . . . . .. EXPERIMENT NO. 9. KRUEGER——SIX 1112.40, or REGISTERED HEREFORDS. This lot consisted or six pure bred Herefords, two bulls and four heifers, whose ages ranged from 6 to 12 months. They were raised near Emporia, Kansas, and had been shipped south, where they ar- rived December 7th, 1898, at the Carter Ranch in Bee county, Texas. » On December 17th, 1898, each received 1 cc. of defibrinted blood from the jugular vein of a 3-year-old cow on the ranch. This cow had a considerable number of ticks on her at this time. The calves were kept in a dry lot and fed bran and cactus, and watered from a cister-n.. January 23rd, 1899—Saw these calves. All have lost flesh, and there is marked looseness of the bowels. They are evidently in the secondary reaction fever period today. Their evening temperature is: Bull No. 1, 106 degrees; bull No. 2, 105 degrees; heifer No. 366, 105.8 degrees; heifer No. 51, 107 degrees; heifer No. 52, 106.5 degrees; heifer No. 57, 104.2 degrees. Februarg/ 6th, 1899—Temperature has fallen to the following: Bull No. 1, 104 degrees; bull No. 2, 104 degrees ; heifer No. 366, 103.5 degrees; heifer No. 51, 103 degrees; heifer No. 52, 102.5 de- grees; heifer No. 57, 104 degrees. _ June 27th, 1899.—Saw these cattle today. Heifer No. 366 is evi- dently pregnant. The cattle appear in good shape. _ _ September 15th, 1899—Bull No. 1 in good thriving condition. Bull No. 2, inoculation has caused arrest in development in this » "fpvwv" the heifers are safe in calf. TEXAS FEVER. 99 calf. He has been thin, but is doing well now. The heifers have done well; the oldest one dropped a calf recently. No deaths. EXPERIMENT NO. 1o. N UTT——N IN E HEAD 0F REGISTERED HEREFORDS This lot consisted of nine pure bred Herefords, raised in Hartley county, Texas. There was one bull and eight heifers. They had been shipped by rail, and arrived at the Nutt Ranch in Bee county, Texas, on January 17th, 1899. On January 23d, 1899, each received 1 cc. of defibrinatcd blood from the jugular vein of a 2-year-old heifer which had been raised on this ranch, and which had ticks on her at the time. They were fed bran and cactus daily. The inoculation did not cause much dis- turbance or loss of flesh. Saw these cattle June 27th, 1899. A.ll have considerable number of ticks on them and appear in good flesh. No deaths. EXPERIMENT No. 11. CooKiFIFTY-FIVE HEAD OF HEREFORDS. This lot consisted of fifty-five pure bred Herefords, forty-one heifers and fourteen bulls. Their ages ranged from one month to 22 months. Eight of them were raised in Illinois, and the re- mainder in Hartley county, Texas. They were shipped south by rail and reached Bee county, Texas, February 2d, 1899. On February 14th each individual received 1 cc. of defibrinated blood from a 2-year-old heifer. These inoculations were made by Dr. Stephens. This lot has done very Well. One death occurred from inoculation and one from blackleg. June 27th, 1899: Saw these cattle. All have a considerable number of ticks on them, yet they are all in good condition. EXPERIMENT N O. 12. RHEA—FIFTEEN HEAD or REGISTERED SHORTHORNS. This lot consisted of thirteen pure bred Sho-rthorn heifers, 8 to 15 months old, and two bulls 12 months old. All had been raised in Missouri. They were shipped south by rail and arrived in Collin county, Texas, April 9th, 1899. April 15th, each received subcu- taneously 1 cc. of defibrinated blood from a 6-year-old cow. No serious symptoms developed. June 24th, each received a second in- oculation of 1 cc. of blood from the same cow as the first dose. A letter from the owner of these cattle, dated August 29th, 1899, says that all of the above cattle have done well, and he thinks all No deaths. 100 TEXAS AGRICULTURAL EXPERIMENT srxrrorvs. DISOUS-SION OF EXPERIMENTS. From the experiments reported in the preceding pages, it will be seen that immunity against Texas fever may be brought about in two ways. It is our purpose at this time to review only those ex~ . periments in which the infection was introduced by inoculation with infected blood) The practical application of this method requires some explanation as to the details of management and attention to the animals, that are necessary to insure satisfactory results. The matter may be accomplished by either of two: methods of proceedure. - I. The first may be called the Northern plant In this instance the cattle are confined in suitable quarters until the dangerous effects of the innoculation have passed, before sending them south. The Inost suitable time for this Work is in the early fall. This allows sufficient time for the animals to recover from the more severe fea- tures of the disease before the rough weather of xvinter sets in; which is very trying on young animals infected with Texas fever. The best attention to diet and comfort of the cattle is necessary. We have been feeding a hay of mixed timothy and clover and a grain ration composed of equal parts of crushed corn, oats and bran. These details are mentioned because the success of innoculation is, in a great measure, dependent upon the skill displayed in keeping the animals properly nourished. At this season of the year sorme grass is available, which is greatly appreciated by fevered cattle, as they often refuse all other food. The time required for recovery from the effects of innoculation varies in different animals. As a general rule, fifty’ to sixty days are sufficient ; but in the practical handling of a lot of cattle there will be some individuals that will not have recovered their strength by the expiration of the time mentioned; and there will probably be others that have failed to react sufficiently to the first innoculation, and thus require a second dose; thereby causing some delay in ship- ping the whole lot at one time. It would be inadvisable for such cattle to arrive in the infected district in Texas before December 1st, because of the danger of gross tick infestation before winter. II. THE SECOND PLAN of management may be called the South- ern plan. In this instance the cattle are taken south before innoc- ulation. This should be done in winter, after there have been sev- eral severe frosts. In Texas this would be about January 1st, as a rule. A suitable place should be prepared, some months previously, to receive and hold the cattle. To do this, the best plan seems to be to enclose a small pasture, about the previous July, and allow no Texas cattle in it after that time. About December 1st burn the grass off and erect suitable sheds for shelter. Very few ticks will survive such measures. TEXAS FEVER. 101 The cattle should be put in the above described enclosure immed- iately on their arrival, and allowed some time to recover from the effects of their journey; say ten to fifteen days, before being innoc- ulated They will require some time to adjust themselves‘ to a new diet. It will be seen from examination of experiment N o. 8 that this may be done gradually w"ithout any marked digestive disturb- ance. We have noticed some calves contract a very troublesome di- arrhoea from having access to cotton seed in large quantities. As a rule, however, they may in a few weeks be taught to eat cotton seed hulls and a mixture of bran, oats and cotton meal without marked digestive disorder. In many parts of the state the cactus is abund- ant. This is a very suitable food for cattle during the inoculation fever, as it contains a mucilaginous substance which has a laxative effect. If this be not available, a few acres planted in oats furnishes an excellent winter pasture. The cattle should be kept from tick infested grounds until the inoculation fever has entirely passed away. Putting this period at sixty days, it would be March 1st be- fore it would be reasonably safe to expose them to ticks. AGE OF ANIMALS. The most suitable subjects for inoculation are young cattle from 8 to 12 months of age, and in good condition as to flesh. They should weigh from 500 to 800 pounds. Younger animals bear the inoculation quite well, but they are usually somewhat hard to man- age orn account of not having learned to thrive on a grain and hay rati-ocn. In some experiments yet under way, we find that young calves, yet nursing their mothers, recover from inoculation prompt- ly; but as their mothers cannot be inoculated with safety, or be taken to the infected district without great danger, the use of calves so young is not desirable from the business point of view of a South- ern buyer. SOURCE OF BLOOD FOR INOCULATION. In all the experiments reported in. this bulletin, except No. 5, the blood was taken from immune Southern cattle. In experiment No. 5 the first dose was taken from a Missouri steer that had been rendered immune by tick infestations. Our knowledge of the quality of immune blood is yet very meagre. The most we can say is that the safe course to pursue is to test the quality of the blood from each individual supply animal. SIZE OF DOSE. The initial dose of infected blood should be small. A study of the experiments shows that it varied from ]. to 2 1-2 cc. of fresh 102 TEXAS AGRICULTURAL EXPERIMENT STATIONS. blood. In experiments 1 and 2 larger quantities were used because the blood could not be used for one or more days after being drawn, and in these instances certain antiseptics were added which probably destroyed the vitality of some of the Texas fever germs. Since the initial dose of 1 cc. of fresh blood is capable of producing a high fever and marked destruction of the blood corpuscles, it must be unsafe to give a much larger quantity (see experiment NOa 8). At the present state of our knowledge, we must regard a first dose of 1 to 2 cc. within the limits of safety, for calves 8 to 12 momths o" age. IN OOULATION FEVER. The fever resulting from inoculation appears about the tenth day. In some instances it was a day or two earlier, and in others a few days later. This is the primary reaction. It usually ap- pears suddenly, with a morning temperature of 104 or more, and rises to about 106. In experiment No. 4, bull No. 12 had a tem- perature of 107.4 on the tenth day; and bull No. 13, 108.4 on the twelfth day. These high temperatures are unusual. The fever of the primary reaction continues several days; then falls rapidly, and has ceased about the twentieth day. A glance at the graphic rec- ord of a part of the animals in experiment No. 4, will make this feature of Texas fever readily understood. The sudden fall in the temperature is a critical time with the animal. Some sub-normal temperatures are recorded, and the deaths that occur are usually at this time, from collapse. If the temperature soon rises to nor- mal, the chances for recovery are favorable. Bloody urine was not noticed in any of the experiments under consideration. The de- struction of the red blood corpuscles during the primary reaction is rapid. In experiment No. 8 we found that the average per cent had fallen to 23.1 by the close of the primary fever period. This destruction of the blood corpuscles causes the blood to become thin and watery, and to contain the broken down material of which the corpuscles were composed. This implies that new corpuscles must be rapidly formed to perform the functions of those destroyed, and that the broken down material must be eliminated in some w-ay from the system. There seems to be considerable evidence that the new corpuscles are formed in the red marrow of the bones, in certain types of connective tissue, and possibly in such circum- stances, in some of the so-called “blood glands.” Therefore, whatever immunity be acquired by animals which have had the disease in question, it seems, for the best we know, to be brought about by the ability of the cells and tissues of the calf’s body to supply the demands made upon it for new corpuscles, and to eliminate the waste products. The latter duty falls to the TEXAS FEVER. 103 liver and kidneys. It is apparent then, that in the practical man- agement of inoculation fever, the animal’ s strength should be main- tained by proper nourishment, and that the eliminative organs be kept active. The bowels and kidneys must be kept active. This can best be managed by suitable feeding. If these measures fail, salts may be given in doses of twelve ounces. A small pasture of winter oats will provide suitable grazing. In the north, a mixture of equal parts of corn meal, bran, ground oats with a small quantity of old process linseed meal added, and clover hay. If po-ssible, let the animal have some green grass. In the South, use a mixture of equal parts of cotton seed meal, bran and oats, with hulls for roughness. When the cactus is available, it may be used to ad- vantage when cut to suitable size and sprinkled with bran. SECONDARY REACTION. The secondary fever period begins about the thirtieth day after inoculation. In experiment No. 8 it appeared on the tvsrenty-ninth day. It resembles the primary one in a general way, but differs from it in being somewhat irregular in its course. An examina- tion of the graphic record accompanying experiment No. 4 will show the variations met with. In bulls 1, 3, 15, 12 and 13 the sec- ondary fever was lower than the primary. In bull 26 it was higher. In .bulls 14, 18, 21, 2, 7 and 19p the difference was not so great. The remarks in regard to attention and care during the primary reaction apply to the secondary as well, and need not be repeated. In experiment No. 8 it will be noticed that a second fall in the percentage of blood corpuscles occurred duricng the secondary re- action. The lowest average for the six animals, reading 21 per cent., occurred on the thirty-ninth day. The lowest individual at this time was 14 per cent. The secondary reaction, in Experiment No. 8, terminated on the forty-third day. In Experiment No. 4, bull 19 had passed through it by the thirty-sixth day; bull No. 14 on the fortieth day; bull 26 on the forty-sixth day. Bull 2 was evidently fevered when the experiment closed. These cases are cited to show the variations encountered. From the data before us at this time, we find that the time re- . quired for cattle to recover from inoculation fever is about fifty days. They should not, therefore, be exposed to ticks before the expiration of the time mentioned. SECOND AND THIRD INOCULATIONIS. A study of Experiment No. 3 shows that the cattle were inocu- lated in October, and that they did not become infested with any considerable number of ticks until the following July, when some twenty or moreof them became sick and ten of the number died. 104 runs AGRICULTURAL EXPERIMENT STATIONS. It seems from this that whatever immunity may have been brought ' aborut by the inoculation in October, was either 10st, or was too fee- ble to prevent deaths during the following July. It would seem . that these cattle should have received a second dose, perhaps in February or March. There is no satisfactory way of ascertaining in such cases, the condition of the animal except by centrifugal analysis of the blood. If this should show a low percentage of the red blood corpuscles, say 25 per cent. or less, and especially should an inspection of the individual show chronic blood destruction, then a second inoculation would probably not be necessary. On the contrary, as a second inoculation causes little or no dis- turbance in those which possess immunity, and as it causes fever in those which do not possess it; the practical thing to do in such cases is to make a second inoculation. Moreover, if the primary reaction has been mild, say below 105, and there is no marked evidence of blood destruction, it would seem reasonable to give the second dose, say sixty days after the first one. A THIRD INOCULATION was given in experiments 2, 5 and 8. While but one death occurred among these animals, a study of the clinical notes in Experiment 5 shows that two of the animals (bulls 534 and 540) contracted Texas fever, though they recovered. Evi- dently three inoculations failed to produce a perfect immunity in these bulls. This matter, then, must await further study. EFFECTS OF INOCULATION. The fever and changes that result from inoculation with infected blood are the same in nature as those that occur when the disease has been contracted in the natural way. Among these, we find: 1st. Recovery with immunity; this is the result desired, and re- quires no further notice at this time. 2nd. Partial recovery with chronic blood destruction; this type occurs in a small percentage of cases. They require prolonged care and the very best of food and attention to prevent an arrest in de- velopment. This occurs especially in pampered animals of high breeding, and often results in a failure of the animals to develop into the individual that it was reasonable to expect from his breeding. 3rd. Death from inoculation fever; two deaths occurred from inoculation in Experiment No. 3. No data are available as to the details. Several deaths occurred in Experiment 6 soon after inocu- lation. It is possible that the latter were, in some considerable measure, due to the infestation with ticks which occurred at the time. EFFECTS ON REPRODUCTION. No evil effects of inoculation on the powers of reproduction have been observed in these experiments. I TEXAS FEVER. 105 In Experiment N0. 1, “The bulls have done good service.” In Experiment No. 2, “All the heifers produced good healthy calves the following spring.” In Experiment No. 4-, “The bulls have sired 200 calves.” In Experiment No. 8, “All heifers appear to be pregnant.” In Experiment No. 9, “The oldest heifer produced a good calf 9 1-2 months after inoculation.” In Experiment No. 12, “All the heifers appear tobe pregnant, five months after inoculation.” We have no data as to the dangers of abortion following inocula- tion. On this point J. S. Hunt (Pathologist to the Department of Agriculture, Queensland, in annual report for 1897-98, page 87) says: “The risk is also greater in cows that are in calf; abor- tion frequently follows inoculation when considerable fever occurs.” Immunity to Texas fever then, is not absolute. It depends upon the ability of the cells of the aniimal to resist the germs of the dis- ease. Whatever operates to reduce this power of resistance, whether it be the fatigue of a long journey on the cars; the exposure of in- oculated cattle to the rough Weather of a Northern winter; the lack of suflicient food during the droughts of summer; the enervating influences of a warm climate; excessive tick infestation; these things, singly or im combination have a tendency to bring on a re- lapse. It is therefore important that inoculated animals be not subjected to extreme conditions, for a year or more. From the experiments before us, we conclude that in careful hands and with proper management, preventive inoculation is a reasonably safe and practical measure against the fatal type of Texas fever. October, 1899. Young Fever Ticks —“Boophltus Bovis”—and Eggs-Highly Magnified. 106 TEXAS AGRICULTURAL EXPERIMENT STLTIONS. $53“. oz . .. . . . . .118 mfmwmww ...... :21 mwmmfi 5:8 mmmmw E2522 m2: w. 8w. 2w 5.5.5.5 ml.....fi5m fl ..@=§2. o5. 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