tailieunhanh - Báo cáo khoa học: "Risk factors for delayed conception in Korean dairy herds"

Tuyển tập các báo cáo nghiên cứu khoa học quốc tế về bệnh thú y đề tài: Risk factors for delayed conception in Korean dairy herds | J. Vet. Set. 2006 7 4 381-385 JOURNAL OF Veterinary Science Risk factors for delayed conception in Korean dairy herds Ill-Hwa Kim Hyun-Gu Kang College of Veterinary Medicine Chungbuk National University Cheongju 361-763 Korea Delayed conception is defined as an interval of greater than 90 days postpartum before a cow becomes pregnant again. In this study the risk factors for delayed conception in Korean dairy herds were deteimined by evaluating several reproductive factors in individual cows. The following data was recorded from 1 012 pregnancies in eight dairy herds designated A-H from July 2001 to June 2006 herd cow parity repeated animal cows included 2 3 or more times calving season calving condition abnormal partus postpartum disorders retained placenta metabolic disorders metritis and ovarian cysts and conception. Logistic regression was used to evaluate the effects of these factors on delayed conception. A stepwise procedure was used to obtain the appropriate model a which revealed the herd metritis and ovarian cysts to be significant risk factors for delayed conception. The odds ratio showed that the likelihood of delayed conception increased by and fold for each incidence of metritis and ovarian cysts respectively. Delayed conception was significantly more likely in 2 herds in herd A by fold and in herd B by fold compared with herd H. These results suggest that the prevention of postpartum metritis and ovarian cysts as well as improved herd management will be needed to maintain a short interval between calving and conception in Korean dairy herds. Key words dairy cow delayed conception diseases herd risk factors Introduction Poor reproductive performance is an important limiting factor in the productivity of dairy herds and the reproductive performance of a cow plays an important role in the culling decisions made by farmers 2 In order to attain a recommended calving interval of 12-13 months cows need conceive within 85-110 days after