title: The effect of claw horn disruption lesions and body condition score at dry-off on survivability, reproductive performance, and milk production in the subsequent lactation.
abstract: The objective of this study was to evaluate the effects of claw horn disruption lesions (CHDL; sole ulcers and white line disease) and body condition score (BCS) at dry-off on survivability, milk production, and reproductive performance during the subsequent lactation. An observational prospective cohort study was conducted on a large commercial dairy in Cayuga County, New York, from September 2008 until January 2009. A total of 573 cows enrolled at dry-off were scored for body condition and hoof trimmed; digits were visually inspected for the presence of CHDL. The BCS data were recategorized into a 3-level variable BCS group (BCSG), with cows with BCS<3 placed in BCSG 1 (n=113), cows with BCS=3 placed in BCSG 2 (n=254), and cows with BCS>3 placed in BCSG 3 (n=206). Cows in BCSG 2 were 1.35 and 1.02 times more likely to conceive than cows in BCSG 1 and 3, respectively. The cull/death hazard for BCSG 1 cows was 1.55 and 1.47 times higher than for cows in BCSG 2 and BCSG 3, respectively. Milk yield for cows in BCSG 2 (44.6 kg/d, 95% CI 43.4-45.8) was significantly greater than that for cows in BCSG 1 (41.5 kg/d, 95% CI 39.8-43.3). Cows with previous lactation days open<or=91 had 1.6 times higher odds of being classified into BCSG 1 at dry-off; cows with previous lactation mature-equivalent 305-d milk>14,054 kg had a similar 1.6 times higher odds of being classified into BCSG 1. Claw horn disruption lesions were found in 24.4% of the cows (n=140) at dry-off. Cows without CHDL were 1.4 times more likely to conceive than cows with CHDL. Additionally, lesion cows were 1.7 times more likely to die or be culled than nonlesion cows. Absence of CHDL did not have a significant effect on milk yield. These findings highlight the importance of claw health and BCS at the end of lactation on future survival and performance.
authors: Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.
authors: V S
authors: VS
authors: Machado
authors: L S
authors: LS
authors: Caixeta
authors: J A A
authors: JA
authors: McArt
authors: R C
authors: RC
authors: Bicalho
mesh_terms: D000818:Animals; D001824:Body Constitution / Q000502:physiology; D002417:Cattle / Q000502:physiology*; D003612:Dairying; D005260:Female; D005534:Foot Diseases / Q000503:physiopathology / Q000662:veterinary*; D006724:Hoof and Claw / Q000473:pathology; D053208:Kaplan-Meier Estimate; D007774:Lactation / Q000502:physiology*; D007794:Lameness, Animal / Q000503:physiopathology; D016018:Least-Squares Analysis; D008136:Longevity / Q000502:physiology; D008892:Milk / Q000378:metabolism*; D012098:Reproduction / Q000502:physiology