Tuyển tập các báo cáo nghiên cứu khoa học quốc tế về bệnh thú y đề tài: Risk factors for retained placenta and the effect of retained placenta on the occurrence of postpartum diseases and subsequent reproductive performance in dairy cows | J. Vet. Sci. 2005 6 1 53-59 JOURNAL OF Veterinary Science Risk factors for retained placenta and the effect of retained placenta on the occurrence of postpartum diseases and subsequent reproductive performance in dairy cows Yeon-Kyung Han Ill-Hwa Kim College of Veterinary Medicine Chungbuk National University Cheongju 361-763 Korea The objectives of this study were to determine the risk factors for retained placenta by evaluating several reproductive factors in individual cows and to determine the effects of retained placenta on the occurrence of postpartum diseases and subsequent reproductive performance in dairy herds. The health status cow parity calving and breeding dates were recorded from 805 calvings in nine dairy herds from October 2000 to March 2004. We used logistic regression to evaluate the effects of these factors on the incidence of retained placenta. A stepwise procedure used to obtain the appropriate model with a revealed that abnormal partus and gestation length were important risk factors for retained placenta. The occurrence of endometritis and metabolic disorders was greater p in the group with retained placentas than in the control group. The mean intervals from calving to first service and conception were prolonged p by 7 and 18 days respectively in the group with retained placentas compared to the control group. These results suggest that abnormal partus and gestation length are strongly correlated with the development of retained placenta which increases the occurrence of postpartum diseases and subsequently decreases reproductive performance in dairy herds. Key words Retained placenta risk factors postpartum diseases reproductive performance dairy cows Introduction Expulsion of the placenta usually takes less than 6 to 8 hr after parturition in cows 52 53 . In practice the most commonly used definition of retained placenta is the presence of fetal membranes 24 hr or longer postpartum Corresponding author Tel 82-43-2612571 Fax
