Studies And Application Of Productive Technologies System On Full Scale Embryo Transfer In Meat Sheep

Productive technologies system on multiple ovulation and embryo transfer in meat sheep under practice conditions were studied and applied. Some associated factors and theories were discussed in this study. The results were as follows:1. Borderdale and Poll Dorset ewes from New Zealand were superovulated by the treatment with FSH﹢PMSG.The donors were treated with CIDR and the recipient ewes were treated with CIDR and vaginal sponges for sychronization. The time of onset of estrus after CIDR withdrawal were 20.12±2.95h and 18.70±2.47h in two dornor groups respectively. They were 46.32±18.96h and 51.04±22.03 h respectively(P>0.05) in recipient groups after CIDR and vaginal sponges withdrawal.The two breeds did not show significant differrence in their overall mean superovulatory response,while a great individual animal variation to superovulatory response and embryo yield was seen within each breed, with producing a range of 1 to 20 embryos in Boderdale and 1 to 26 embryos in Poll Dorset. Out of total Borderdale 52.73% yield 7 to 12 embryos and of total Poll Dorset 52.30% yield 1 to 6 embryos respectively.The first and second repeated superovulation treatments in Borderdale and Poll Dorset gave 7.00,5.62 and 8.00,9.08 embryos in average respectively, among which the usable embryos accounted for 61.90%,72.60% and 87.50%,88.11% respectively in two breeds.Embryos were collected on Day 7 post oestrus and two breeds ewes produced a much higher proportion of morula, they were 66.24% in Borderdale and 75.78% in Poll Dorset. The higher percentage of expending and hatched embryos were obtained (31.75% and 22.33% in Borderdale and 25.89% and 31.75% in Poll Dorset respectively) on day 8 post oestrus.The distribution of ovulation between the right and the left ovary was recorded. There were more ovulations on the right ovary (52.59%) compared to the left ovary (47.4%, p>0.05) in Borderdale, while...