Studies On The Estrous Synchronization, Superovulation And Embryos Freezing Conservation In Qinchuan Cattle

To preserve the local cattle breeds, founding embryos collection is one of the most effective and economical method. In this experiment, 20 Qinchuan catties were used for estrous synchronization and superovulation. The embryos obtained from Qinchuan catties were used for freezing conservation. The objective of this paper was conducted to establish an optimum method for estrous synchronization, superovulation and embryo freezing conservation of Qinchuan cattle, and some affect factors were also investigated, the results as follows:1. The Qinchuan cattle were treated for estrous synchronization by using 4 different methods: Use CIDR only (method â… ); CIDR + PG (method â…¡); Inject PG only (method â…¢); Inject PG twice, with the interval 11 days (method â…£). The result shows that the estrous synchronization rates were 60.0%, 75.0%,53.3% and 79.3% respectively, the estrous synchronization rate of method â…£(79.3%) was significantly higher than method â…¢(53.3%)(P<0.05).2. 20 Qinchuan cattle were treated with injecting PG twice, with the interval 11 days, for estrous synchronization, totaling 84 treatments. The result shows that there was no significant different between the estrous synchronization rate treated in summer, autumn (form May to October) (82.5%) and treated in witer, spring (from November to April) (75.0%)(P>0.05).3. 20 Qinchuan cattle were superovulated with FSH produced in Canada, totaling 31 treatments, 20 treatments were effective with the rate 64.5%, and 6.45 embryos were obtained on average. Among them, 4.20 embryos were transformable.4. 20 Qinchuan cattle were superovulated by different FSH dose: 240mg, 300mg and 340mg. The average number of corpus luteum per cattle of three groups were not significantly different (P>0.05). The embryos obtained from each cattle (9.20) and useful embryos (7.00) of the 300mg FSH group were significantly higher than groups that treated with FSH 280mg and 320mg per cattle (P<0.05).5. 20 treatments of superovulation were carrid out. There was not any significant different between the average number of corpus luteum per cattle superovulated in summer, autumn (from May to October) (12.82) and treated in witer, spring (from...