Interest in dairy cow comfort is due to the belief that greater comfort implies better animal welfare and that cows housed in low-stress environments are more productive. The most obvious indicator of a cow’s comfort is the proportion of her daily time budget that she spends lying down.
While earlier studies of lying behaviour were dependent on visual observation, more recent studies have made use of motion sensor technology to continuously record the activities of dairy cows. The sum of all of these studies, published since 2000, has demonstrated that lying behaviour in free-stall barns is affected by:
- pen and alley size, layout and flooring;
- stall location relative to feeding and milking facilities;
- stall dimensions, surface and bedding quality and quantity;
- stocking density – the number of usable stalls available per cow;
- social interactions between cows;
- heat stress;
- the amount of time cows are restricted from access to stalls;
- individual cow parity, stage of lactation, production level and health status.
Since lameness has become the dairy industry’s primary animal welfare issue, a question that has been addressed in a number of recent studies is: Can lying behaviour be used as an indicator of lameness?
A 2011-12 Canadian study assessed lameness and lying behaviour in 5,135 cows on 141 free stall farms in Québec, Ontario and Alberta. In addition to confirming the influence of some of the factors listed above, this study drew several practical conclusions:
- average daily lying time among the 5,135 cows was 10.6 hours. 95% of the cows had daily lying times between 6.0 and 15.2 hours (see distribution in figure 3 below);
- there was more variation in daily lying time among individual cows in each herd than there was in average lying times among herds;
- the relationship between herd average lying time and herd lameness prevalence was of no practical significance (figure 1);
- for individual cows, there was considerable variation in daily lying time over 4 days of recording (figure 2);
- the probability of an individual cow being lame increased if her daily lying time was markedly lower or higher than average (figure 3). However, this was not an accurate enough predictor of lameness to be used as a diagnostic indicator without confirmation by physical examination of suspect animals.
The complete, peer-reviewed summary of the Canadian study is available here.