Growth, reproduction and herbage utilization in Japanese Black and Brahman sired crossbred cow and their calves

点击翻译按钮获取中文摘要

This study was carried out to examine whether introduction of the germ plasm of Brahman breed was effective or not for increasing the grazing ability, herbage utilization and growth potential of Japanese beef cattle.l. Herbage utilization in grazing was evaluated for F_1 of Brahman(Z)* X Japanese black(B), Japanese Shorthorn(N)and Holstein(H)* and BB cows. F_1 exceeded BB in herbage intake per metabolic body weight. F, was larger in both intakes of NDF and TDN per body weight than BB, supporting from differences of their contents(%)within herbage in pasture before and after grazing.2. In milk yield estimated by weig-suckle-weigh method of calves, Z-H, ZN and NN were largest and BB was smallest, ZB and BN were intermediate. These indicated that effects of breed on milk yield were larger in dam breed than in sire breed. Average daily gains(ADG)of calves from dam groups were largest in ZH, ZN and NN and smallest in BB, ZB and BN were intermediate. ADG was corresponding to milk yield of dam.3. ADG, herbage utilization and behavior in grazing were evaluated for calves of 1/4 Z(BB* X ZB, ZN, ZH*)and BB. 1/4 Z was larger in both of ADG and herbage intake per metabolic body weight than BB. There were no differences in dry matter and protein digestibilities between two groups, but 1/4 Z tended to be, respectively, higher in fiber digestibility and longer in grazing time than BB. It was suggested from these results that 1/4 Z had more nutrient intakes during grazing than BB.These results demonstrated that(1)Brahman crossbred F, was superior to Japanese beef breeds, especialy Japanese Black in grazing ability, (2)these characteristics were existing in 1/4 Brahman crossbred calves.