The effects of feed bunk competition on the feed sorting behavior of close – up dry cows

Abstract

ABSTRACT<br><br>The objectives of this research were to describe the<br><br>feed sorting, feeding behavior, and feed intake of cows<br><br>consuming a close-up ration and to determine if these<br><br>behaviors are affected by competition for access to the<br><br>feed bunk. Thirty-six dry Holstein cows, consuming a<br><br>close-up total mixed ration diet, were assigned to 1 of<br><br>2 treatments: 1) noncompetitive (1 cow/feed bin) or 2)<br><br>competitive (2 cows/feed bin). Dry matter intake, feeding<br><br>behavior, and sorting behavior were monitored for<br><br>each feed bin on 4 separate days during wk 2 and 3<br><br>before the anticipated calving dates of the cows. Fresh<br><br>feed and orts were sampled daily from each bin and<br><br>were subjected to particle size analysis. The particle<br><br>size separator consisted of 3 screens (18, 9, and 1.18<br><br>mm) and a bottom pan resulting in 4 fractions (long,<br><br>medium, short, and fine). Sorting was calculated as the<br><br>actual intake of each particle size fraction expressed as<br><br>a percentage of the predicted intake of that fraction.<br><br>Regardless of treatment, the cows sorted against long<br><br>particles and for short and fine particles. Competition<br><br>at the feed bunk had no effect on the sorting behavior,<br><br>dry matter intake, or feeding time of the cows, but did<br><br>dramatically increase the feeding rate of the cows. The<br><br>competitively fed cows also had fewer meals per day,<br><br>and tended to have larger and longer meals. Our results<br><br>suggest that increased competition at the feed bunk<br><br>promotes feeding behavior patterns that will likely increase<br><br>the between-cow variation in composition of total<br><br>mixed ration consumed.