title: Risk factors for post partum ovarian dysfunction in high producing dairy cows in Belgium: a field study.
abstract: An epidemiological study of risk factors for postpartal ovarian disturbances was carried out on 334 high-yielding dairy cows in 6 well-managed Belgian herds. Ovarian activity was closely monitored using progesterone profiles, based on twice weekly RIA-analysis for progesterone in milk fat, starting at 10 d after calving and continuing until the confirmation of a new pregnancy. Attention was focused on abnormal cyclicity during the preservice, postpartum period; cows were divided into 6 different categories. Three of these categories (normal profile, delayed cyclicity, and prolonged luteal phase) were of major importance and were analyzed using a multiple variable logistic regression model. Season of calving (stable vs pasture, odds ratio (OR)=5.7), an extended length of the previous dry period (> 77 vs < or = 63 d, OR=2.9), problem calvings (OR=3.6), abnormal vaginal discharge (OR=4.5), health problems during the first month of lactation (clinical disease, OR=5.4; ketosis, OR=11.3), and clinical parameters illustrating the appearance of a severe negative energy balance significantly increased the risk for delayed cyclicity before service. Parity (> or = 4 vs 1, OR=2.5), problem calvings (OR=2.9), occurrence of puerperal disturbances (OR ranged from 3.5 to 11.0), health problems during the first month of lactation (OR=3.1), and an early resumption of ovarian cyclicity after calving (< 19 d vs > 32 d, OR=2.8) increased the risk for prolonged luteal cycles before service.
authors.affiliation: Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
authors.forename: G
authors.initials: G
authors.lastname: Opsomer
authors.forename: Y T
authors.initials: YT
authors.lastname: Gröhn
authors.forename: J
authors.initials: J
authors.lastname: Hertl
authors.forename: M
authors.initials: M
authors.lastname: Coryn
authors.forename: H
authors.initials: H
authors.lastname: Deluyker
authors.forename: A
authors.initials: A
authors.lastname: de Kruif
mesh_terms: D000818:Animals; D001530:Belgium; D002417:Cattle; D002418:Cattle Diseases / Q000209:etiology*; D004971:Estrus; D005260:Female; D007774:Lactation; D016015:Logistic Models; D008183:Luteal Phase; D008892:Milk / Q000737:chemistry; D010049:Ovarian Diseases / Q000209:etiology / Q000662:veterinary*; D011247:Pregnancy; D011374:Progesterone / Q000032:analysis; D011644:Puerperal Disorders; D012307:Risk Factors; D012621:Seasons
chemical_list: D011374:Progesterone