[Evaluation of the effect of Presynch Ovsynch program on reproductive performance of dairy cows with retained fetal membrane]

Retained fetal membrane decreases reproductive performance of dairy cows. The objective of this study was to evaluate the effect of Presynch Ovsynch protocol on reproductive performance of retained fetal membrane cows in Iranian dairy farm. This experiment accomplished on 244 Holstein dairy cows of a commercial dairy herd in Tehran. At least 24 hour after calving, the cows with or without retained fetal membrane were allocated into Presynch-Ovsynch and control groups, randomly. Commencement of injection in Presynch-Ovsynch group was between 23 and 27 days post calving, and cows were inseminated at 60-61 days after calving. In control group, cows were inseminated based on observation of estrus after voluntary waiting period. Data were analyzed using ANOVAand Chi-square. Days of first service were lower in synchronized cows than the control ones [61.5 vs. 105.5; p<0.05]. Days open was lower in Presynch Ovsynch treated cows with history of retained fetal membrane than untreated cows with history of retained fetal membrane [124.2 vs. 169; p=0.007]. Proportion of cows conceived by 200 days in milk was smaller in untreated cows with history of retained fetal membrane compared with cows in other groups [64% vs. 85.3%; p=0.007]. In conclusion, using Presynch-Ovsynch protocol and timed insemination improve fertility and reproductive performance in retained fetal membrane cows through decreasing days open