Evaluation of Pregnancy Per Artificial Insemination of Dairy Animals Showing Estrus and Assigned to Conventional or Sexed Semen

Three experiments were designed to evaluate the effects of sex-sorting technologies on reproductive performance of dairy females showing estrus. In Exp. 1, 978 lactating Holstein cows and 116 Holstein heifers were used, and were randomly assigned to receive conventional (CONV) or sexed (SEXD) semen on day 0 of a TAI protocol. The TAI was performed using commercial CONV or SEXD frozen-thawed semen from the same 6 Holstein bulls, SEXD semen was sorted through fluorescence cytometry. In Exp. 2, 390 lactating Holstein × Gir dairy cows and 344 Holstein × Gir heifers were used and randomly assigned to receive CONV or SEXD semen on day 0 with frozen-thawed semen from 5 Holstein × Gir bulls. The SEXD was sorted through the SexcelTM methodology. In Exp. 3, 789 primiparous lactating Holstein cows were enrolled and randomly assigned to receive CONV or SEXD semen from 5 Holstein bulls, the SEXD semen was sorted as in Exp. 2. In Exp. 1, multiparous assigned to CONV had greater P/AI vs. cohorts assigned to SEXD (P < 0.01) and similar response tended to be observed for secundiparous cows (P = 0.10). In Exp. 2, no P/AI differences between treatment were detected either on days 32 (P = 0.32) or 60 of pregnancy (P = 0.20). In Exp. 3, cows assigned to SEXD had reduced P/AI on day 32 (P = 0.03) and tended to have a reduced P/AI on day 60 of pregnancy (P = 0.06). Overall P/AI of SEXD semen was 78% of the CONV.