Quantifying behavioural priorities-effects of time constraints on behaviour of dairy cows, Bos taurus

In order to quantify the relative priorities between lying, eating and social behaviour of dairy cows in different stages of lactation, responses to time constraints were investigated in two experiments. In experiment one, 48 dairy cows, half in early and half in late lactation, had free access to lying, eating and social contact in a resource pen for 23 h (2 × 11.5), 15 h (2 × 7.5) or 12 h (2 × 6) a day. Rest of the day, the cows were deprived of eating, lying and social contact. In experiment two, we examined whether the time constraint on eating alone affected feed intake and eating behaviour using 32 cows kept in tie-stalls, half in early and half in late lactation. Half of the cows had free access to feed for 24 h a day and the other half had access to feed for 12 h a day. Reducing the time with free access to the resources reduced the time spent on all behaviours measured, but the proportion of time spent lying increased while the proportion of eating and social behaviour remained constant. Speed of feed intake was increased when the time budget was reduced; thus, the relative reduction in feed intake was less than the relative reduction in eating time. Time constraints on access to feed alone did not reduce feed intake. Stage of lactation did not affect the relative priorities between behaviours. In conclusion, lying time had higher priority than eating time and social contact in both early and late lactation, and cows compensated to some extent for a reduction in eating time by increasing the rate of feed intake.