DISEASE AND RELATED PHENOMENA IN ANIMAL BREEDING 531 



new breeds. The former manner of utilization is relatively simple 

 it requires merely that herds of both pure-bred cattle and zebus be main- 

 tained; the latter mode of employment necessitates long continued selec- 

 tion before stability of characters will have been reached. 



If zebu cattle are to be used for obtaining cross-bred commercial 

 stock, it is necessary that the immediate hybrids possess superior charac- 

 ters for such purposes. This matter appears to be in some doubt, but 

 discounting the opinion of those who are blind partisans of the Northern 

 breeds, it appears that zebu-Northern crosses unite many of the favorable 

 characters of both breeds. The cross is very easily made. Thus Pucci 



FIG. 206. An F i zebu-Hereford heifer. The Hereford characters appear to be predom- 

 inant. (From the Journal of Heredity.) 



reports upon the results of using a Gujarat bull on cows of the Maremma, 

 Romagnola, and Perugia breeds in experiments conducted at the Perugia 

 Institute of Animal Husbandry in Italy. Of 113 cows used only nine 

 failed to give calves, and these nine were also barren when mated with 

 bulls of their own breeds. 



With respect to the characters of the F\ offspring there seems to be a 

 considerable difference of opinion. Pucci who has apparently studied 

 the matter most thoroughly states that zebu characters are dominant 

 with respect to fineness of skeleton, abundance of dewlap, development 

 of ear, slope of rump, and general muscular development. It appears 

 to be generally agreed that the crosses are more vigorous and growthy 

 than the parents ; according to early reports, they exceeded either parent 

 by 50 per cent, in this respect. According to Nabours the predominant 

 appearance of zebu characters in the FI offspring occurs only when range 

 cattle are used. He ascribes this fact to the presence in range cattle of 

 a strong infusion of zebu blood. He found that when crossed with 



