Effects on Reproductive Parameters of Cosynch, Ovsynch and Ovsynch+Cosynch Administration in Unobserved Estrous Cows and Heifers
1. March 2009
This study was carried out to compare effects on the pregnancy rates achieved by timed AI (TAI) of cosynch,
ovsynch and cosynch+ovsynch protocols in lactating dairy cows (60 d postpartum) and heifers (16-18 m old) in
which the state of estrus is not determined. In group I (cosynch) cows (n: 97) and heifers (n: 43) were treated
with an intramuscular. injection of synthetic GnRH (10μg) on day 0. 7 d after the GnRH injection they were
given an i.m. injection of PGF2α (25 mg) and a second injection of GnRH (10mg) 48 h after the PGF2α injection.
Keywords: Pregnancy, unobserved estrus, cosynch, ovsynch, cosynch+ovsynch, heifer, cows
