title: The association between lameness, ovarian cysts and fertility in lactating dairy cows.
abstract: The objective of this observational study was to evaluate the association between lameness, ovarian cysts, and fertility in lactating dairy cows. Data analysis of historical records from a 3000 Holstein farm was conducted. Sixty-five cows that became lame within 30 days postpartum were used as cases, and 130 nonlame cows served as controls. The outcome variables were incidence of ovarian cysts (OC, %), conception rate at first service (CRFS, %), overall pregnancy rate (PR, %), and calving to first service interval (CFSI, day), Incidence of OC and CRFS were analyzed by logistic regression, PR by survival analysis and CFSI by ANOVA. Lame cows had a lower CRFS (17.5% versus 42.6%) and higher incidence of OC (25.0% versus 11.1%) than controls (P<or=0.05). Calving to first service interval was not different between lame and control cows (P>0.05). There was a multicollinearity relationship between lameness and ovarian cysts. The results show that cows that became lame within the first 30 days postpartum were associated with a higher incidence of ovarian cysts, a lower likelihood of pregnancy, and lower fertility than control cows. Because this is an observational study it is not possible to conclude a cause-effect relationship.
authors.affiliation: Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, P.O. Box 100136, Gainesville, FL 32610, USA. melendezp@mail.vetmed.ufl.edu
authors.forename: P
authors.initials: P
authors.lastname: Melendez
authors.forename: J
authors.initials: J
authors.lastname: Bartolome
authors.forename: L F
authors.initials: LF
authors.lastname: Archbald
authors.forename: A
authors.initials: A
authors.lastname: Donovan
mesh_terms: D000818:Animals; D016022:Case-Control Studies; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology / Q000503:physiopathology*; D005260:Female; D005298:Fertility; D015994:Incidence; D007247:Infertility, Female / Q000150:complications / Q000453:epidemiology / Q000662:veterinary*; D007774:Lactation / Q000502:physiology; D007794:Lameness, Animal / Q000150:complications / Q000453:epidemiology / Q000503:physiopathology*; D010048:Ovarian Cysts / Q000150:complications / Q000453:epidemiology / Q000503:physiopathology / Q000662:veterinary*; D011247:Pregnancy; D018873:Pregnancy Rate; D011446:Prospective Studies; D013997:Time Factors