EFFECT OF HORMONAL TREATMENT ON FERTILITY IN DAIRY-COWS WITH DYSTOCIAOR RETAINED FETAL MEMBRANES AT PARTURITION

Holstein cows (n = 445) that had experienced dystocia, retained fetal membrane, or both at parturition were used to determine the effects of GnRH, PGF(2 alpha), or both on various reproductive measurements. Cow s affected with these conditions were assigned randomly to each of fou r treatment groups. One group of cows was untreated, and three groups received GnRH once at 12 d postpartum, or GnRH at 12 plus PGF(2 alpha) at 26 d postpartum, or PGF(2 alpha) given at 12 and 26 d postpartum. Another group of 191 cows that calved normally were untreated. Concept ion rate after first AI was higher for cows treated with PGF(2 alpha) at 12 and 26 d postpartum. Cows affected with dystocia, retained fetal membranes, or both and treated early postpartum with GnRH alone or fo llowed 14 d later with PGF(2 alpha) did not have improved reproductive performance. Cows calving during the summer months of June through Se ptember experienced a reduction in the reproductive traits examined.