BMY牛提前产犊试验

目的]为提高母牛的利用年限、缩短后备母牛的培育时间、探索BMY青年牛的适配年龄（体重）和提前妊娠产犊对母畜和犊牛的影响。方法]对断乳母犊进行适当培育,使其早进入初情期,运用繁殖生物技术妊娠产犊。结果]经过培育后BMY青年牛的初情期平均为（270.8±20.8）d,此时的平均体重为（254±10.6）kg,发情周期...

Study on Early Calving of BMY Heifer

【Objective】The trial was conducted to enlarge the cow＇s utility duration,shorten the breeding period of heifer,explore the suitable mating age or body weight of heifers and the effect of early pregnant and calving on mother and calves.【Method】Biological breeding techniques and applicable nursing on BMY weaning female calves were used to achieve the forwardness of puberty,pregnancy and calving.【Result】The result showed that the puberty period of BMY heifer was 270.8±20.8 d and the puberty weight was 254±10.6 kg.The estrous cycle was 20.5±2.0 d and the duration estrus was 19.7±2.4 h.The suitable mating age was about 290～300 d（suitable mating weight was about 250～280kg）.The average gestation was 282d and the average birth-weight of calves was 33.52kg.The daily gain of calves was over 0.7 kg during lactation,and the development of cows was well after calving.【Conclusion】It demonstrated that the reproductive performance of one-years-old heifer was the same with the adult after applicable nursing on BMY weaning female calves,and more than 80% of BMY heifer could produce the first calf at the age of 20～24 months.Early calving had no harmful effects on female and calves;which could achieve good economic benefit and give full play to reproductive performance of female.