Effect of stocking density on the short-term behavioural responses of dairy cows

Abstract

The objective of this research was to measure the effects of increased stocking density of stalls and headlocks on the short-term behavioural responses of lactating Holstein cows. Multiparous ( n = 92) and primiparous ( n = 44) cows were assigned to four pens of 34 cows each and stocking densities (100, 113, 131, or 142%) were imposed in a 4 × 4 Latin square design with 7-d periods. Stocking density was adjusted by altering access to free stalls and headlocks. Activity of the cows was recorded continuously with digital video cameras for the last 2 d at each stocking density and time spent as well as mean percentage of cows engaged in lying, standing, and feeding at each 10 min scan sample was determined. Mean percentage of cows feeding over a 24-h period was approximately 20.5% and cows spent approximately 5 h/d feeding, but the percentage of cows feeding during the first 60 min following return from the milking parlour declined ( P < 0.009) with increasing stocking density (67.2, 60.4, 55.0, and 54.8% for 100, 113, 131, and 142% stocking density, respectively). Time spent standing in stalls decreased ( P < 0.01; 2.5, 2.3, 2.2, and 2.1 h) whereas time spent standing idly in an alley increased ( P < 0.001; 1.7, 1.9, 2.6, and 3.1 h) as stocking density increased above 113%. A linear relationship was observed between stocking density and the percentage of cows lying, standing, and idly standing in an alley. The results of this short-term study indicate that stocking densities of stalls and headlocks greater than 100–113% altered the behaviour of lactating dairy cows.