. GIFT OF KB, .-.: EVIDENCE OF ALTERNATIVE INHERITANCE IN THE F2 GENERATION FROM CROSSES OF BOS INDICUS ON BOS TAURUS DR. ROBERT K. NABOURS NEW YORK 1912 [Reprinted without change of paging, from the AMERICAN NATURALIST, 1912.] [Keprinteri from TH£ AMERICAN NATURALIST, Vol. XLVL, July. 1912. J KVIDENOE OF ALTERNATIVE INHEEITANCE IX THE F_ GENERATION FROM CROSSES OF BOS INDICUS ON BOS TAURUS DR. ROBERT K. NABOURS KAKSAS STATE AGRICULTURAL COLLEGE THE common domestic cattle of India appear to be a distinct §pecies (Bos iiidicus). They are mainly charac- terized by a large hump on the fore shoulders, short horns, large drooping ears, extensive dewlap and sheath (Fig. 1). There are several varieties, or breeds, but they are so commonly hybridized that it is exceedingly difficult to ascertain which are the pure strains and which hybrids. In this respect they are probably analogous to Bos taunts. In size they vary greatly, ranging from very diminutive breeds to those the largest individuals of which weigh upwards of 2,000 pounds. Th8 526789 129 •////•: .l.i//-.7//r.l.V NATURALIST [VOL. Xl.\'l Fi'.. 1. Imported bull (Bun im/iVi/.-- 1. When In good condition. this bull \V4>ij:hs U.^im imuUils. are used on the banana plantations. It is generally re- ported that the strong draught oxen of Spain have been derived from crosses between Indian cattle and the native Spanish cattle, but the evidence is at best only anecdotal and nothing whatsoever seems to have been recorded of Fio. 2. Cows and calves (Has intlii-u* i. Xo. 547] ALTI-:J!\.[?IVK IXIIERITANCE IN BOS 430 the inheritance behavior of the progeny of any of the crosses. The hump of some of the largest specimens may weigh as much as fifty pounds, and it is esteemed by English residents of India as a delicacy for the table. From the Persian province of Gilan, on the Caspian, the humps, smoked, of a small breed are shipped to parts of Russia where they are in much demand as a delicacy. The meat, products of these cattle, on the whole, are said to be unexcelled. Some of the breeds give milk that is ex- cessively rich in quality, but it does not appear that any of them produce it in large quantities. It appears that Brahma (Bos indicus) cattle were first brought to the United States in 1853 by Mr. Davis, of South Carolina. These cattle were subsequently taken westward and their progeny distributed throughout the southwest and parts of Mexico. In southern Texas and parts of Mexico there are many native cattle that are said to carry the blood of these cattle and other Indian stock which were secured from menageries and circuses. The common brindle cattle of these regions are said to be descendants of the Indian on native cattle. Wherever these part Indian cattle are found there is a general im- pression among stockmen that they are thriftier and larger than the native stock and more resistant to the ravages of diseases, ticks, and insect pests. .In 1906 Mr. A. P. Borden, of Pierce, Texas, imported about thirty head of Brahma cattle, mostly young bulls,, and since then he has been crossing them quite exten- sively on native Texas cattle and on grade Durhams and on grade Herefords. For an account of the experiences in importing these cattle and the beginning of the experi- ment, the reader is referred to Mr. Borden 's interesting paper, "Indian Cattle in the United States," The Ameri- can Breeder's Magazine, Vol. 1, No. 2. In September, 1911, Mr. Borden kindly permitted me to visit his herds for the purpose of studying them and making photographs. The following preliminary ac- 431 '////. .\Ml-:illc.\X NATURALISE [VOL. XLV1 count of three of the herds is -iven. hccause they tend to show definite inheritance results. The study of the herds and the work of making the photographs were greatly hampered l.y tlie absence of the head herdsman, the rain. I'li;. .". !•', hybrids from ISn* imlii-iiK mi Ileivi'ord. The heifer on Hie right • il l.Hcill pounds ;ll t \vrlve ninnllis "1 :ige. 'I'll.' lillll .ill the left weighed J.4.">i> JM, mids MI twein.v six iiinnllis of ;i(ie. riintii fiiniislu-il liy Mr. A. !'. llonleii. and the very short time at my disposal. I plan to make a further study of them at an early date. Whenever the Brahma cattle have heen crossed on irrade or pure I lerefords, the color characters of the latter are on the whole dominant in the F, progeny (Figs. I '!•; t. llytiriils from litts indicii* on Hereford :in«l I>urham. The bull in the center Is from Hereford mother and weighed about 1.40O pounds at 22 months of age. All nre tick-free. Xo. 547] ALTERNATIVE JM/l-:iilT. \.\CK IN BOS 432 3 and 4). The F, progeny from crosses on grade Dur- ham show the Durham color and other characters to be dominant. The progeny from crosses on native Texas cattle of unknown constitution are very variable. In some cases the F, progeny from the latter resemble the Brahma greatly. However, this apparent dominance ot the Brahma in many cases, when crossed on native cattle, is probably altogether due to the fact that a considerable proportion of the native cattle already have Brahma characters in them — their immunity to ticks and other de- sirable qualities having favored their perpetuation since the early 'introduction of the Davis and other Brahma stock. HEED No. 1 This herd consists of twenty-five or thirty Fl cows (Fig. 5, adults) from a white Brahma sire on grade Dur- l-'n:. .">. F! mothers from Bus intlicus on grade Durham and a few grade Here- fords. The white calf, urh.-un. and the calves from these I'i cows hred hack to Has im/iYn*. ei|iial proportion. These Fl cows show the color char- acters of the Hereford and Durham quite distinctly, 1'n:. 7. The yearlings are from /;•,* iiiilirus x high-grade Hereford I"i hylirids hri-d back to Bon iinlii-iix. though there is slight evidence of the hump of the Brahma sire, and the dewlap is somewhat enlarged (Fig. No. 547] ALTEIIXATIVK IXJIEWTAXCE IX DOS 434 0, adult). (The brothers of these cows were not ob- served.) The F2 calves of this herd are from a Brahma sire on these Fj cows. My notes fail to show whether or not the sire of the F2 calves is the same as that of their F! mothers. The sire of the F2 calves appears to be in- termediate in color between the white and brown Brahma. The calves are of two distinct types, about one-half of them having the Brahma characters and the other half bearing the characters of their hybrid mothers (Fig. 6, calves). In the figure (Fig. 6) a good type of the hybrid resembling the mother is the sucking calf at the right, while several apparently pure Brahmas are shown in the foreground. HERD No. 3 The Fj cows of this herd are the progeny from a Brahma sire on high grade Hereford cows. The F2 calves and yearlings are from another Brahma sire on the Brahma-Hereford hybrid. On counting these thirty-two calves and yearlings, it was found that seventeen of them resemble mostly the sire and grandsiro Brahma while fifteen come nearer to the type of the hybrid mothers (Fig. 7, calves and yearlings). CONCLUSIONS CONCERNING THE INHERITANCE BEHAVIOR It appears that the color patterns of Herefords and Durhams are dominant in the Fl generation. However, the hump, large sheath and dewlap of the Brahma show slightly in the Brahma X Hereford or Durham F1 progeny. It is clear that in the F2 generation, pure Brahma and pure Durham are segregated. Indications are that when the parent strains are pure the segregation follows the simple law of alternative (Mendelian) in- heritance. However, the conditions of the experiment, the lack of full knowledge of the constitution of the parents and the inadequate observations prevent any positive conclusions as yet concerning the ratios. 435 •/•///•: AMERICAN NATU&ALIS1 [VOL. XLVI IM.MI-XITY TO THE TKXAS CATTI.I: TICKS I am able fully to confirm Mr. Borden's statements (foe. rit.) that the pure Brahma cattle and the hybrids are perfectly immune to the Texas cattle tick. Fig. 8 shows the ordinary conditions of the native Durham or HerelWd rattle, while Figs. '.), 1 and :! show the condi- Fio. 8. A tlck-ini'i'sti'il llerefnnl COW. Kir,. 0. A Bos indictts cow free from ticks. Karh of these cows has suckled a calf (lurini; HIM sumniMi- and hotli have been together in the same pasture. tions of the pure Brahma and hybrids all running together on the same range. I was not able to ascertain definitely the inheritance behavior of this character (im- munity to ticks) in the F2 progeny. However, it is ex- pected that data on this point will be available in the or summer of 191± SIZE AND PROLIFICNESS The statement by Mr. Borden (loc. cit.) that the hybrids running on the range average about 50 per cent. No. 547] ALTERNATIVE 1\HKU1'I'A.\ < !•: IX BOS 430 larger than the ordinary native range cattle is fully con- firmed by my observations. The hybrids shown in Fig. 4 (center), which had had no other advantage than the range conditions, weighed 1,400 pounds at two years old. The hybrid heifer, shown in Fig. 3 (at the right), which had run on the range, weighed 1,000 pounds at twelve months old. The bull, Fig. 3 (on the left), weighed 1,450 pounds at 26 months of age. These weights appeared to me to be more than 50 per cent, greater than the average of the native cattle at the same age kept under similar circumstances. A pure '-Brahma bull will put seventy-five to eighty cows with calf each season, while the native or even high- grade Hereford or Durham will impregnate only twenty- five or thirty cows. I desire to express my gratitude to Mr. Borden for courtesies shown me while studying and photographing the herds and for reading and correcting the manuscript, and to Professor T. J. Headlee for the arrangements which made the trip possible; I am further^ indebted to Professor Headlee for suggestions while writing the paper and arranging the illustrations. UNIVERSITY OF CALIFORNIA LIBRARY BERKELEY Return to desk from which borrowed. This book is DUE on the last date stamped below. 260ct'50B LD 21-100wi-ll,'49(B71468l6)476 •e o (inheritance r native .in th" F? ': v-'"'^' •$&& UNIVERSITY OF CALIFORNIA LIBRARY :V-;"=': ^ ' ':•'''• ' \ ••-. ': *.%*;. •f'^J:- --,;*::