Dorper Sheep, Frozen Embryo Transfer Study

This paper investigated that the cryopreserved embryos of Dorper sheep imported from New Zealand were transferred into the recipients of Hu sheep and Han sheep in different seasons, and the efficiency of the frozen embryo transfer was analyzed and estimated. The results showed that the average of estrus synchronization ratio of total recipients was 72.56%, utilization ratio of lambs in estrus was 49.66%, pregnancy ratio was 57.05%, birth rate was 53.86%, birth weights of lambs were 4.33 kg (in male) and 4.27 kg (in female), and lamb weights of one month, three months and six months were 14.45 kg, 29.58 kg, and 46.54 kg respectively. 440 frozen embryos in total were transferred into 440 recipients in the 4-batch experiments, in which 251 lambs were born, and 231 lambs survived. There were also different results of embryo transfer experiments within batches or breeds of recipients. The efficiency of embryo transfer in Autumn and Winter is higher than in Spring. Hu Sheep is better than Han Sheep in each batch.It is concluded that the cryopreserved embryos of Dorper sheep transferred into the recipients of Hu Sheep in Autumn and Winter is more reliable and more effective. This result is expected to be applied widely to researcher and reproduction of animal husbandry field.