title: Effect of lameness on ovarian activity in postpartum holstein cows.
abstract: A longitudinal study was conducted to examine the relationship between lameness and delayed ovarian cyclicity during the first 60 d postpartum and days to first luteal activity during the first 300 d postpartum in Holstein cows. Two hundred thirty-eight cows from a 600-cow dairy that calved during a 12-mo period were used. Cows were classified into 1 of 6 categories of lameness during the first 35 d postpartum using a locomotion scoring system. Cows were blood-sampled weekly for detection of plasma progesterone concentrations during the first 300 d postpartum. Cows with delayed resumption of ovarian cyclicity were defined as those with progesterone concentrations consistently <1 ng/mL during the first 60 d postpartum. The null hypothesis that risk of delayed cyclicity is the same in cows classified as nonlame, moderately lame, or lame (after adjusting for potential modifying or confounding effects of loss of body condition and other variables related with delayed cyclicity) was tested using logistic regression. Analysis of results of the study reported here support the hypothesis that lameness is associated with delayed ovarian activity in Holstein cows during the early postpartum period. Cows classified as lame had 3.5 times greater odds of delayed cyclicity, compared with cows classified as nonlame. Attributable proportion analysis indicated that delayed ovarian cyclicity in lame cows would be reduced by 71%, if lameness had been prevented.
authors.affiliation: College of Veterinary Medicine, Department of Large Animal Clinical Sciences, University of Florida, Gainesville, 32610-0136, USA.
authors.forename: E J
authors.initials: EJ
authors.lastname: Garbarino
authors.forename: J A
authors.initials: JA
authors.lastname: Hernandez
authors.forename: J K
authors.initials: JK
authors.lastname: Shearer
authors.forename: C A
authors.initials: CA
authors.lastname: Risco
authors.forename: W W
authors.initials: WW
authors.lastname: Thatcher
mesh_terms: D000818:Animals; D002417:Cattle / Q000502:physiology*; D002418:Cattle Diseases / Q000503:physiopathology*; D030762:Estrous Cycle / Q000502:physiology*; D005260:Female; D007794:Lameness, Animal / Q000503:physiopathology*; D016015:Logistic Models; D008137:Longitudinal Studies; D016017:Odds Ratio; D010060:Ovulation / Q000502:physiology; D049590:Postpartum Period; D011374:Progesterone / Q000097:blood*; D012098:Reproduction; D013997:Time Factors
chemical_list: D011374:Progesterone