Department of Obstetrics and Genital Diseases, Faculty of Veterinary Medicine, University of Tehran, Tehran- Iran
Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, University of Tehran, Tehran- Iran
BACKGROUND: Retained fetal membrane decreases reproductive performance of dairy cows. OBJECTIVES: 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. METHODS: 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 ANOVA and Chi-square. RESULTS: 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). CONCLUSIONS: In conclusion, using Presynch-Ovsynch protocol and timed insemination improve fertility and reproductive performance in retained fetal membrane cows through decreasing days open.