黄牛双胎素的研究

黄牛为单胎动物，对豫西７５０００头秦川及秦川杂种母牛连续两年（１９９０～１９９１）的调查资料表明，黄牛的自然双胎率为０．００７８％。１９９０～１９９２年，我们利用超数排卵原理，在豫西地区对５１８头秦川及秦川杂种母牛进行试验，研究出了一种复合激素配方。将该复合激素于发情周期第１７～１８天注射于２０７头母牛的左臀部肌肉，待发情后配种，使母牛每个情期双卵发育率达到７５．８４％，双卵排放率达到７０．０４％，受双胎率达到４３．３１％，活产双犊率达到２２．９２％。试验证明，使用该双胎素可大大提高母牛双胎率，为加速养牛业的发展开辟了一条新途径。

STUDIES ON COMPOUND HORMONES LEADING To CATTLE TWINNING

Cattl belongs to monotocous animal species. The data based on 75000 Qinchuan cows in western part ofHenan province in two consecutive years(1990～199l)had shown that the twinning rate was 0.0078%, During1990～1992, according to the principle of superovulation, we carried on a series of experiments on 518 Qinchuancows in western part of Henan province and developed a hormone complex which was injected into the left buttockof 207 Qinchuan cows on the 17～18th day of their heat cycle, the double-follicle development rate in each estrouscycle was waised to 75. 84%; doubleovulation rate to 70.04%; twin-pregnancy rate to 43. 31% and twin-born rateto 22. 92%. These experiments have shown that the application of this hormone complex can greatly increase thereproductive effciency of cows and providc a new way to speed up the development of cattle production.