Milk Production, Body Condition Score and Metabolic Parameters at the Peak of Lactation as Risk Factors for Chronic Lameness in Dairy Cows

The objective of this case-control study was to examine the milk production, body condition score and metabolic profiles at the peak of lactation as risk factors for chronic lameness present in cows during the first six months of lactation. A total of 100 Holstein-Friesian cows were enrolled in the study, out of which 30 were classified as lame (a locomotion score (LS) > 3 according to 4 of 5 monthly measurements) and 70 exhibited no signs of clinical lameness (LS <= 3). The cows with milk production above 30.9 kg/day showed a higher risk for chronic lameness (OR= 1.9, a 95% confidence interval (CI)= 1.2-4.5), and the risk peaked at a milk production of 39.1 kg/day (OR= 4.8, CI= 2.1-8.8). A suboptimal BCS < 2.5 or > 3 at the peak of lactation increased the probability of lameness in the exposed group of cows (OR= 4.9, CI= 2.2-8). The cows were exposed to higher risk factors for chronic lameness under the following circumstances: BHBA> 0.8 mmol/L (OR= 3.5, CI= 1.2-9.9), LDH> 1900 IU/L (OR= 2.3, CI= 1.4-5.9), and triglycerides> 0.22 mmol/L (OR= 2.2, CI= 1.5-2.9). The interaction between two risk factors showed a higher OR for developing chronic lameness in comparison with a single-factor exposure: BCS x BHBA (OR= 22, CI= 1.2-1000), BCSxLDH (OR= 33, CI= 1.8-1400), milk production x BHBA (OR= 18.24, CI= 2.1-433) and milk productionxLDH (OR= 14.2, CI= 1.5-327). Lameness cows exposed to risk factor showed un-significant lower concentration of urea, ALP and higher concentration of cholesterol and triglycerides probably due to energy and protein malnutrition. Glucose concentrations were similar in healthy and lameness cows. Same mean concentration of glucose was maintained with decrease of LDH activity in healthy cows, but with increase LDH in lame cows, probably due to high glycolysis. Metabolic adaptation in pick of lactation and its relation with lameness need further research.