Effect of Animal Grouping on Feeding Behavior and Intake of Dairy Cattle

Abstract

Although data are scarce, it is clear that grouping strategy can have a significant impact on the feeding behavior and feed intake of dairy cattle. Feed intake is controlled by rumi-noreticular fill and physiological mechanisms, but grouping is a component of the cow's feeding environment that can modu-late intake as a result of its impact on cow comfort, competi-tion for feed and other resources, and herd health. Social dominance and competition for feed impact feeding behavior and proper grouping strategy will minimize the negative im-pact of excessive competition on intake and enhance benefi-cial effects of group feeding such as social facilitation. Primi-parous cows benefit from separate grouping from older ani-mals by increased intake and productivity. Bunk space, acces-sibility of feed, and type of feeding system must be considered when determining the optimal group size. There appears to be no problem with large (>200 cows) groups of cows per se, but management decisions such as overcrowding with insufficient head gates or manger space play a role in determining cow well-being and feeding behavior. Research with group sizes larger than 400 cows needs to evaluate productivity, feeding and other behavior, and animal well-being. Significant over-crowding appears to reduce feeding activity, alter resting be-havior, and decrease rumination activity. Negative social con-sequences of moving cows between groups last 3 to 7 d. Al-though the effect of grouping on feeding behavior remains largely unquantitated at this point, the effect is potentially large and requires further research to describe the impact of cow dynamics within a group on feed intake.