. Genetics in relation to agriculture. Livestock; Heredity; Variation (Biology); Plant breeding. DISEASE AND RELATED PHENOMENA IN ANIMAL BREEDING 533 that in crossbreeding, namely of keeping pure-bred herds of both zebu and Northern cattle and continually crossing them. Central herds of zebus could easily be established to supply the demand for zebu bulls. Zebu bulls appear to be more prohfic than Northern bulls, for it is possible with them to count upon an average of about sixty calves per year from each bull. The utilization of the hybrids for the establishment of a new breed is another mat
. Genetics in relation to agriculture. Livestock; Heredity; Variation (Biology); Plant breeding. DISEASE AND RELATED PHENOMENA IN ANIMAL BREEDING 533 that in crossbreeding, namely of keeping pure-bred herds of both zebu and Northern cattle and continually crossing them. Central herds of zebus could easily be established to supply the demand for zebu bulls. Zebu bulls appear to be more prohfic than Northern bulls, for it is possible with them to count upon an average of about sixty calves per year from each bull. The utilization of the hybrids for the establishment of a new breed is another matter, and one requiring long time and careful attention. It should, however, be carried on under competent guidance such as might be afforded by experiment station Fig. 207.—Bison bull, Bison americanus. (Courtesy National Zoological Park, Wash- ington, D. C.) The other hybrid which gives some promise of use in American agriculture is that obtained by crossing the bison and domestic cattle. Reciprocal hybrids may be obtained, but apparently it is easier to get hybrids by using a bison bull on domestic cows. This hybrid represents a more violent cross than the zebu hybrid, inasmuch as considerable difficulty attends the production of hybrid progeny. Cows very often die while calving, apparently on account of the ph3'sical difficulties involved in giving birth to the hybrids, which possess a considerable hump like that on the bison. The hybrids are intermediate between the parents in respect to most characters. In vigor and size they are su- perior to either parent; from the market standpoint both with respect to flesh and coat they are very desirable animals. Practically all the animals which have been born have been females, and these are fertile. A Digitized by Microsoft®. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly
Size: 1993px × 1254px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksu, booksubjectplantbreeding
