Studies And Application On The Techniques Of Estrus Synchronization And Artificial Insemination In Mutton Sheep

In order to make use of foreign introduced ram effectively, and to enlarge the breeding population, we carried out systemic studies on cmprehensive reproduction techniques of ram production including ewe synchronized estrus technique, ram breeding and management models, semen low-temperature preservation methods, semen cryopreservation diluents and artificial insemination methods.Three ewe synchronized estrus methods were studied to investigate their validity. Results showed that fertility efficiencies of using a vaginal plug and of sex hormone 1 are significantly higher than that of sex hormone 2 (P<0.01), while there is no significant difference between that of vaginal plug and of sex hormone 1 methods. Considering the simpleness in operation and low cost of the vaginal plug method , it is the best choice in ewe synchronized estrus treatment.Four breeding and management models were investigated to research their effects on ram semen quality. Results showed that breeding and management model plays great effect on ram semen low-temperature preservation quality. The model of feed supplementating plus grazing can improve ram semen quality.Three low-temperature preservation diluents were studied to compare their efficiencies. Results showed that the the sperm viability of using milk diluent is significant lower than that of using diluent A and C (P<0.01), while there is no significant difference between t diluent A and C. According to this experiment, ram semen can be preserved for 167 hours at low temperature in diluent A. The sperm viability after 77 hours is 70%. The living time of ram sperm at room temperature is about 72h, thus low-temperature preservation can greatly prolong the living time of ram sperm.Five semen cryopreservation diluents were screened in this experiment. Results showed that there are significant difference of these five diluents on the effect of frozen sperm (P<0.05). the post-thawed sperm viability of diluent 2, 3 and 4 is significantly higher than that of diluent1nd 5(P<0.05).In order to improve the conception rate of frozen semen, traditional insemination method was reformed. Results showed that the average conception rate of using the reform insemination method is 62.7%, which is significantly higher than that of the traditional method, which is only 32.3% P<0.01).