大额牛冻精在瘤牛超数排卵中的应用效果及F_1代的亲子鉴定

Application of Frozen Sperm of Mithun in Superovulation of Zebu and Parentage Identification of Crossbred F_1(Mithun×Brahman)

【目的】本研究旨在探讨大额牛(Bosfrontalis)冻精在瘤牛(Bosindicus)体内胚胎生产及杂交改良中的应用前景。【方法】对9头瘤牛(婆罗门牛)供体进行超排,发情后将供体分为试验组(n=5)和对照组(n=4),分别用大额牛和瘤牛(婆罗门牛)冻精人工授精(AI),以第1次AI之日为0天,在第7天回收胚胎;对试验组287号供体左侧子宫角回收胚胎,右侧子宫角使胚胎继续着床妊娠;对287号母牛所产F1代犊牛(大额牛×瘤牛)进行亲子鉴定;测定F1代牛的初生、6月龄和12龄的体重、体尺指标。【结果】试验组和对照组供体的受精率分别是90.5%和80.8%,头均获胚数分别是4.2±1.3枚和6.5±4.7枚,可用胚数分别是3.0±1.2枚和4.3±5.3枚,可用胚率分别是71.4%和65.4%,两者差异不显著(P>0.05);287号母牛左侧子宫角回收到2枚可用胚,右侧子宫角内胚胎继续发育,并成功产下1头母犊,妊娠期为288d;对F1代犊牛亲子鉴定显示,9个微卫星座位上犊牛与公牛、犊牛与母牛都具有共享的等位基因,父子关系相对机会(RCP)为99.9949%,证明此例亲子鉴定的确是一个三联体家庭,从而证实了种间杂交的真实;F1代牛的初生、6月龄和12月龄重分别为31.5kg、180.0kg和280.0kg;初生～12月龄平均日增重达680.8g。【结论】大额牛冻精在瘤牛超排中应用效果好;并获得国内首例大额牛(独龙牛)与瘤牛杂种牛犊;F1代牛生长较快,杂种优势明显。

[Objective] The objective of this paper was to discuss the application foreground of embryo production and crossbred improvement of zebu （Bos indicus） with frozen sperm of Mithun （Bos frontalis ）. [Method] Nine donors of zebu （Brahman） with estrous after superovulation were divided into experiment group （n=5） with frozen sperm of Mithun and control group （n=4）with frozen sperm of zebu （Brahman） for AI, respectively, And embryo was recovered on day 7 after AI. No. 287 of Brahman cow was from experiment group, whose embryo in the left uterine was flushed and another embryo in the right uterine was developing continuously on day 7 after AI. No. 287 cow gave birth to a crossbred calf （Mithun×Brahman） and parentage identification was carried out by collecting frozen semen of Mithun and the blood of No. 287 of Brahman cow and crossbred calf assaying 9 microsatellite loci. The body size and weight of the calf was mensurated at the ages of birth, six-month and twelve-month, [Result] The results of experiment group and control group were 90.5% and 80.8% in fertilized ova rates, 4.2±1.3 and 6.5±4.7 in average recovered embryos, 3.0±1.2 and 4.3±5.3 in average transferable embryos , and 71.4% and 65.4% in transferable embryo rates, respectively, of which were not significantly difference between the two groups （P〉0.05）. As a result, two transferable embryos recovered from the left uterine, embryo developing in the right uterine of No, 287 of Brahman cow was 288 days of pregnancy length and finally given birth to a calf cow. The results of parentage verification showed that the calf and the bull, the calf and the cow shared the 9 microsatellite loci, and relative chance of paternity （RCP） was 99.9949%, indicating the case was a triple family, and it＇s true that the potential of interspecies crossbreeding between Mithun and Brahman. The weights at the ages of birth, six-month and 12-month of F1 calf were 31.5 kg, 180. 0kg and 280.0 kg, respectively. And average daily weight gain of calf from birth to yearling was 680.8g. [Conclusion] An excellent effect was obtained when frozen sperm of Mithun was applied in the superovulation of zebu; the first interspecies crossbred calf from Dulong cattle （Mithun or Gayal）×zebu （Brahman） was obtained in China in January, 2006, and the calf grow faster and shows significant heterosis at present.