Research On Reproductive Performance And GDF9 Gene Of Suffolk Sheep

This research was completed in an animal husbandry limited company in Shijiazhuang City,Hebei Province.The reproductive rate of Suffolk ewes,lambing interval,monthly distribution of lambs were measured and analyzed.The effect of semen collection frequency on semen quality of Suffolk rams was analyzed.The multiple candidate gene GDF9 of Suffolk sheep was also studied.The aim of the research is to provide a scientific basis for the reproduction and multiple breeding of the local Suffolk sheep,and to provide reference for the introduction and promotion of Suffolk sheep.The specific results are as follows:1.The average litter size of white Suffolk ewes is 1.66±0.58,and the average litter size of black Suffolk ewes is 1.52±0.53.The gestational period of white Suffolk ewes is 147.25±7.55 days,and the live lambing rate exceeds 90%.The gestational period of the black Suffolk ewes is 151.66±17.05 days.In summary: The reproductive performance of white Suffolk sheep is slightly higher than that of black Suffolk sheep.2.The pregnancy rates of artificial insemination of black and white Suffolk sheep were 160.58%,156.10%,and the average pregnancy rates were 85.58% and71.97%.It is believed that the effect of the artificial insemination of white Suffolk sheep is higher than that of black Suffolk sheep.3.From the perspective of semen volume,sperm motility and sperm density,the best semen collection frequency was 1 time/2 days,1time/2 days,1 time/ 2 days respectively.Comprehensive results suggest that the best suitable semen collection frequency for Suffolk rams is 1 times/2 days.4.An G→A mutation site(G1 mutation,c.260G>A)at the coding region 260 bp of the candidate gene GDF9 for multiple births in Suffolk sheep was identified,where there were two genotypes in the mutation site: GG and GA,and the average lambing size of GG and GA genotypes were 1.75±0.4 and 1.33±0.51,which showed an obvious difference.It is speculated that the G1 mutation of GDF9 gene has a certain regulatory effect on the reproductive performance of Suffolk sheep.Bioinformatics analysis shows that the mutation point G1 of GDF9 gene has a certain impact on the secondary structure of the protein,but it has no effect on the tertiary structure of the protein.