Investigation the effect of using sex-sorted Xsperm in superovulation program on herd expansion and genetic structure

The purpose of this study is to investigate the effect of using Xsperm in embryo transfer on herd expansion and genetic gain in situation all daughters kept in the herd. True breeding values (TBVs) and estimated breeding values (EBVs) of a herd were simulated in Visual Basic 6, for 305 days milk yield trait. Four strategies were assumed in this study. In strategy 1, conventional semen was used for heifer and cow donors. In strategy 2, cows were not donor and sexed semen was used for heifer donors. In strategy 3, sexed semen was assumed for heifer and cow donors and in strategy 4, sexed semen was used for heifer donors and conventional semen was used for cow donors. According the results of this study, the maximum genetic gain achieved for 305 days milk yield by strategy 1-4 was 7.09, 3.9, 7.6 and 7.9Kg, respectively. Using sexed semen in embryo transfer technique, would increase the number of daughters born in the herd up to 11%. If beside embryo transfer, sexed semen is used for artificial insemination of other heifers (that are not donor or recipient), increase in the number of daughter would be up to 34%.