【摘要】 2 70头经产母黄牛分成 3组 ,每组 90头 ,分别在产后 13个月用 2mg(Th组 )或 1mg(Tl组 )精液抑制素和福氏完全佐剂进行主动免疫 ,34周后进行加强免疫。加强免疫所用抑制素剂量减半 ,佐剂为福氏不完全剂。另一组牛用不含抑制素生物活性的精液提取物和上述佐剂进行主动免疫和加强免疫 ,用作对照组 (C组 )。母牛发情时 ,间隔 8 12h用冷冻精液进行人工授精。在主动免疫和加强免疫后 812d采集颈静脉血 ,收集血清 ,分别用双扩散凝胶沉淀法和酶联免疫吸附测定法测定抗抑制素抗体的效价。根据记录完整的 2 4 7头牛资料 ,发现Th组 87头母牛中有 73头(83.9% )发情 ,其中 5 1头排单卵 ,19头排双卵。妊娠期末 ,15头产双胎 (孪生 2 6 .3% ,15 / 5 7)。而在T1组 (72头 )和C组 (88头 )中 ,分别只有 4 4头 (6 1.1% )和 5 5头 (6 2 .5 % )母牛发情 :其中排双卵的母牛分别为 4头和 0。妊娠期末 ,孪生率分别为 3.1% (1/ 32 )和 0 (0 / 34)。分析血清抗体水平 ,证明排双卵的母牛血清抗抑制素水平显著高于排单卵和不排卵的母牛 ,排卵数与抗抑制素抗体水平呈正相关 (r=0 .75 0 7,P <0 .0 1)。更多还原

【Abstract】 Two hundred and seventy multiparous Chinese Yellow cattle (beef) cows were selected at 1 to 3 months postpartum and divided into three groups (90 cows for each). Animals were given both a primary and a booster immunizations with a total dose of 3 mg (Group Th) or 1.5 mg (Group TI) of seminal preparation containing inhibin activity, emulsified with Freund’s complete adjuvant and incomplete adjuvant (for booster), at 3 or 4 weeks intervals. Other cows were treated with same volume of seminal preparation without inhibin activity as procedures mentioned above to serve as a control (Group C). Artificial inseminations were given twice at 8 to 12 h intervals when the cow was in heat. Jugular venous blood samples were collected from each cow and used to assay the presence of antibody against seminal preparation by double diffusion in agar precipitation test and to detect the titer of inhibin antibody by an ELISA method. Data from 247 cows showed that 83.9% (73/87) of cows were in estrus and ovulated 89 ova altogether, of which 19 cows ovulated twin ova and 15 cows produced twins in group Th (n=87). However, only 61.l % (44/72) of cows in group Tl (n=72) and 62.5% (55/88) of cows in Group C were in estrus and ovulated 46 and 52 ova altogether respectively. The ovulation rate (l.27±0.03), calving rate (126.3%) and twinning rate (26.3%) in Group Th were greater than those in groups TI or C (P<0.0 1). Furthermore, the ovulation rate was associated with antibody titer in sera of immunized animals (r=0.7507, P<0. 01). These results indicate that active immunization of postpartum cows against inhibin purified from porcine seminal plasma may increase the ovulation rate and induce twinning, suggesting the potential to develop a method to improve fertility in cows.更多还原