Estrus response patches, timing for artificial insemination, and GnRH protocol in Split Timed AI beef cattle

Abstract An estrous-detection patch was used to determine the optimum timing for STAI and necessity of GnRH at on a 7-day CO-Synch+CIDR protocol. Crossbred beef cows (n=216) were stratified into following treatment groups: CTRL=TAI (n=67) 72 h post CIDR removal, or TRT=STAI (n=149) 84 removal. All females received (100 mcg) plus d0, PGF2α, an Estrotect estrous-detector d7. At post-CIDR score assigned (PS1<50% removed; PS2>50% removed) all females. Cows in CTRL group administered second TAI. TRT with PS2 not GnRH. h, remaining given PS; PS1 mcg), administered. Results: The TAI pregnancy rates similar (P=0.81) between (45.6%) (44.8%) groups. Pregnancy tended be higher (P=0.07) (50.3%) than those (29.4%). However, by extending unresponsive cows, 82.0% did receive injection It concluded that estrous detector patches reduced percentage required without compromising rates. significantly number