| Obective:To study the effect of estrus synchronization,the difference of conception rate and the change of main reproductive hormone levels in different FecB genotypes of Dolang sheep,so as to lay a foundation for the propagation of Dolang sheep by using new breeding techniques in the future.Materials:In this study,Dolang ewes were selected for FecB genotyping by PCR-RFLP.The estrus induced by sponge thrombus PMSG h CG was divided into two groups.The estrus rate was counted and the estrus rate was counted.60 days later,the pregnancy of estrus was examined by B-ultrasound and the conception rate was counted.The concentrations of E2,FSH,LH and P4 in serum of FecB different genotypes polywave sheep during withdrawal of suppository,estrus 0 h,estrus 12 h and estrus 24 h were detected by ELISA.Result:The estrus rates of type B and type multi-wave sheep within 60 hours after thrombus removal were 83.67%and 85.60%,respectively.There was no significant difference between the two groups（P>0.05）.The estrus rate of B+-type multi-wave sheep was found to be oestrus within 60 hours after the withdrawal of the bolt,while 99%of the B++-type multi-wave sheep showed oestrus within 48 hours after the withdrawal of the bolt,the oestrus rate was 84.80%,the pregnancy rate of the B+-type multi-wave sheep was 65.85%,the pregnancy rate of the B++-type multi-wave sheep was 67.65%,and the difference was not significant（P>0.05）.The concentrations of FSH,LH,E2 and P4 were measured by collecting serum samples from 0 h estrus,12 h estrus and 24 h estrus.The results showed that the concentrations of FSH and LH in type B were higher than those in type B at four time points in the observation period,but the difference was not significant（P>0.05）.The E2 concentration in the B+-type serum was significantly higher than that of the B++-type in four time points（P<0.01）,and the E2 concentration in the B+-type serum was significantly higher than that of the B++-type（P<0.01）,and the E2 concentration in the B+-type serum was significantly higher than that of the B++-type in the estrus of 0 h（P<0.05）.The concentration of P4 in type B was higher than that in type B at four time points,and the concentration of P4 in type B was significantly higher than that in type B at the time of thrombus removal（P<0.01）.It was also found that the concentration of E2 in serum of Dolang ewes at 0 h was higher than that in other time points of estrus and estrus cycle,and the concentration of P4 in serum was lower than that at 0 h in estrus and other time points in estrus cycle.Conclusion:There was no difference in estrus rate and conception rate between type B and type multi-wave sheep.Type B multi-wave sheep had longer estrus and estrus within 60 hours after thrombus removal,while 99%of type multi-wave sheep showed estrus within 48 hours.There was no difference in the levels of the secretion of FSH and LH in the B+and++-type,but the levels of FSH and LH in the B+-type ewes were slightly higher than that of the++-type.The secretion levels of E2 and P4 in serum of type B Dolang sheep were significantly higher than those of type B,which was beneficial to the production of more mature follicles in individuals carrying FecB gene.The changes of E2 and P4 were the same as those of the two hormones in the oestrus mechanism of the ewes when the oestrus was 0 h higher or lower than the other time points of the withdrawal and estrous cycle.The above results provide a reference for reducing the number of ejaculation tests and regular indoctrination,and also provide a theoretical basis for the scientific breeding of Dolang sheep by using the new breeding technology. |
