【摘要】 分布于红原及其毗邻地区的牦牛具有较优良的产奶性能和乳质特性。该地区牦牛184天产奶量为211 30kg;乳脂率6 82%,乳蛋白5 60%,乳糖5 20%,均高于黑白花奶牛。暖季适当补饲可提高泌乳黑犏牛日产奶量0 77kg;冷季半舍饲+补饲可使泌乳黑犏牛全泌乳期产量平均提高1096kg,延长泌乳期109～137天。畜群结构调控和常规繁殖技术,可显著提高适龄母牛的群体比率和繁殖率,从而提高群体产奶水平。应用现代生物技术,有望解决牦牛种间杂交过程中存在的一些问题,如提高改良犏牛的繁殖成活率,扩大改良规模、实现改良犏牛繁殖改良犏牛等,可提高牦牛改良的经济效益。更多还原

【Abstract】 Yaks(Bos grunniens)distributed in and around Hongyuan County have a good milk performance and milking characteristics.The average of milk yield per lactation(184d)is 211.30kg.Milk content is 6.82% fat,5.6% protein,5.2% lactose.All of these contents are higher than those of Holstein milk.Supplementation during warm season can increase daily milk yield by 0.77kg in crosses(F1)of yak with Holstein(Bos taurus).House feeding and supplementation together during winter in crosses(F1)of yak with Holstein can increase milk yield per lactation by 1096kg,and prolong length of lactation to 109-137d.The proportion of breeding yak cows and reproductive performance can be significantly increased by manipulation of herd structure and reproductive technology,thus improve milk output.Fertility of crosses of yak with cattle could be possibly improved by biotechnology.This will increase the scale of crossbreeding and can efficiently use crosses.更多还原