Results of a study of 36 herds with automated milking systems (AMS) in Québec, Ontario, Alberta and Michigan identified some of the main risk factors for lameness in those herds. Twenty-five to 40 cows in each herd were scored for lameness, leg injuries, body condition (BCS), and body size (hip width and rump height). Stall and pen measurements as well as routine management practices were also recorded for each farm. Average herd prevalence of clinical lameness was 15%, ranging from 2.5% to 46%.
Stall width relative to cow size and parity was found to be the most important factor associated with lameness (see table below). Not fitting the average stall width increased the odds of being lame by 1.79 times for cows across all parities and 3.7 times for primiparous cows. A narrow feed alley, obstructed lunge space, a low body condition score (BCS ≤2.25 compared with BCS 2.75–3.0), and presence of hock and knee lesions were also identified as statistically significant risk factors for lameness. Only 1 of 36 farms had stalls of adequate width and length for the cows on their farm.
For lameness prevention, the authors of the study conclude that more emphasis needs be placed on either building stalls of appropriate width or selecting for smaller-framed cows that fit the existing stalls.
Complete details of the study, published in the Journal of Dairy Science, are available here.