The Effect Of Sexed Sperm On Pregnancy Rates And Offspring Growth And Development Of Holstein Cows

This study was aim at how to improve the Pregnancy rates of Holstein cows artificial inseminationed with sexed sperm,compared the Pregnancy rates and calves upgrowth between sexed sperm and routine sperm,and carried out the Popularization and Application of sexed sperm .combining sexed sperm with inducing Double-Calving to produce twinning heifers.Reaserch the effect of bulk insemination site (shallow part of uterine horn/deep part of uterine horn),old (heifers/delivered cows), the season (spring/autumn/winter) on Pregnancy rates of sexed sperm. Results shows that Pregnancy rates of sexed sperm separated from different bull were different significantly (P<0.05); pregnancy rates after artificial insemination in shallow part of uterine horn and deep part of uterine horn were 62.50% and 63.33% respectively,there were no differences (P>0.05);pregnancy rates of delivered cow were 43.24%, significantly lower then heifers's 74.19% (P<0.05); pregnancy rates of heifers artificial insemination in spring> autumn and winter were 74.19%,65.71% and 50% respectively,There were no differences (P>0.05).Heifers and cows were artificial inseminationed with sexed sperm and conventional sperm produced by the same bull,at the same condition of insemination does, insemination site,insemination time and insemination personnel. the results showed that pregnancy rate of the treatment group(sexed sperm group) and the control group(routine sperm group) of heifers were 80.00% and 60.00% respectively,there were no differences (P>0.05); pregnancy rate of the treatment group(sexed sperm group) and the control group(routine sperm group) of cows were 33.33% and 57.14% respectively,there were no differences (P>0.05).compared the female rate,abortion rate,calves livability rate, weight and body measurements of neonatal, 3 months , 6 months and 12 months of calves born from sexed sperm and routine sperm. the results showed that The female rate of treatment group(sexed calf) and the control group(routine calf) were 95.45% and 47.37% respectively, difference was extremely significant (P<0.01) .Abortion rate of two groups were 2.94% and 5.00% respectively,there were no differences (P>0.05); calves livability rate of two groups were 92.42% and 92.11% respectively,there were no differences (P>0.05); There were no differences in weight and body measurements of neonatal, 3 months , 6 months and one year of calves born from sexed sperm and routine sperm (P>0.05) .combining sexed sperm with inducing Double-Calving, in estrus synchronization process,the cows were randomly divided into three groups, and intramuscular injection PMSG 1500IU,1200IU and800IU,respectively, 48h before remove the sponge suppository.after oestrus carries on artificial insemination with sexed sperm base on the follicle growth. pregnancy detection with bultrasound 60d later, statistics pregnant rates and twinning rates. Delivered and statistics abortion rates, twinning rates. Results shows pregnant rates that 60d after artificial insemination of three groups were 44. 4%, 37. 5% and 72. 7% respectively,and twinning rate were 50. 0%, 33. 3% and 12. 5% respectively. Total four twin pregnancies cows, one was abortion,both were twinning heifers. The other three twin pregnancies cows calving six heifers, one was dead fetus,and the other five develop normally.The results of Popularization and Application of sexed sperm in Handan,Tangshanqianan and Baodingrongcheng shows that the pregnant rate, abortion rate and female calf rate were 52.1%, 4.5% and 94.0% respectively.