Studies On The Factors Influencing The Effects Of Superovulation And Embryo Transfer In Boer Goats

Factors influencing embryo tansfer are donor super-ovulation, recipient and embryo in Boer goats. Whist super-ovulation is effected by animal states (donor and its genetic differences, physiological and nutritional states, super-ovulation date and season, and many other environment factors which can affect animals) and hormone (half life of the hormones, FSH/LH rate in the medicaments, approach, dosage and frequency of injecting hormones). The aim of this present study is optimizing the technologies of synchronous estrus, super-ovulation and embryo transfer via using hormones to control the follicular and luteal development, estimating the effects of hormone treatments, trying to develop a better protocol which can increase Boer goat super-ovulation rate, so as to make embryo transfer technology serve the stockbreeding better.1 Factors influencing super-ovulation rateThis present study use Boer goats as experiment animals, the effects of superovulation methods, hormone dosages, super-ovulation time, donor corporeity, donor age and hybridization manner on donor super-ovulation effects were analyzed, at the same time, we record ,compare and analyze the reactivity and ovulation of both ovaries from donors.Results suggest the effect of super-ovulation methods on super-ovulation is significant (P＜0.01). The super-ovulation effect of synchronous estrus with one injection of PGF_2α is the best, and the number of average usable embryos is 18.00.The effect of FSH dosage on super-ovulation is also significant. With FSH dosage increasing, the luteal number of multiparous goats increases significantly, so the usable embryo number of multiparous goats do. Using 240IU FSH to make multiparous goats super-ovulation need one injection of PGF_2α. Good super-ovulation effect can be obtained with super-ovulation in any day of oestrus cycle, and the usable embryo number is 12.02-19.03.The effect of donor corporeity on super-ovulation is significant (P＜0.01). The effect of donor age on super-ovulation is also significant (P＜0.5). The usable embryos from multiparous goats are more than from primiparous goats .Hybridization manners have no significant effects on donor super-ovulation effects (P＞0.05). The reactivity of both ovaries from super-ovulation donors has no significant differences (P＞0.05).2 Effect of recipients on embryo transferSelecting suitable recipients is vital to Boer goat embryo transfer. This present study is using Boer goat hybridized F1 goats, Xuhuai white goats and Changjiang delta white goats as experiment animals to determine the degree of oestrus synxhronization between the donors and the recipients, and to estimate the effects of the recipient luteal state and breed and nutrition on the rate of recipient pregnancy. Results suggest recipient oestrus synxhronization has significant effects on its pregnancy rate (P＜0.05). The recipients with the same synxhronization oestrus as donors have the highest success rate of embryo transfer (76.67%). The luteal number and primary follicles have no significant effects on pregnancy rate (P＞0.05).Recipient breed has significant effects on its pregnancy rate (P＜0. 05). Boer goat hybridized F1 goats and Xuhuai white goats are more suitable as recipients than Changjiang delta white goats.3 Effect of embryos on embryo transferThough donors, recipients, season have an important effects on embryo transfer, embryos quality also effect success of embryo transfer. This present study determine the effects of the embryo development stages and the embryo conversation time in vitro and the number of transfer embryos on the embryo transfer. Results suggest the days of embryo development have no significant effects on the accept pregnancy rate (P＞0.05), but the pregnancy rate of 8-16 cell embryos transfered is a little higher than that of 2-4 cell ones (68.42 % vs 63.64 %).The embryo conversation time within 60 minutes has no significant effect on pregnancy rate, but the embryos transfered within 6 minutes have the highest pregnancy rate (64.71%).The recipients with three embryos transfered have higher pregnancy rate than that with one and that with two.(71.43% vs 64.52% vs 52.50 %).