Feeding behavior characteristics of intact male lambs as affected by number of lambs in a pen with restricted access to the feed stall

To investigate the effect of number of animals housed in a pen upon feed intake, 72 intact male lambs were randomly assigned to treatments consisting of 3, 7, 11 or 15 animals/pen in each of two trials. For each animal's feeding event, length of feeding (s) and feed consumption (g) were recorded through use of an automatic feeding system. This system allows one animal to feed at a time. Pens were treated as experimental units with observations repeated daily for 21 d. Response variables were feed consumption (g), time (s) and rate of feed consumed (g/s) per visit and feed consumption (g), average time (s) and number of visits per animal daily. Number of animals/pen was significant for most feeding behavior characteristics. As number of lambs within a pen increased, feed consumption/visit increased linearly in both trials. For Exp. 1, rate of feed consumption/visit increased at a decreasing rate, while in Exp. 2 only the linear effect of lamb numbers on this trait was significant. Daily feed consumption/lamb was greatest for intermediate lamb numbers, and the number of visits and time spent feeding/lamb decreased as the number of lambs within a pen increased. Results suggest that the feeding behavior of ram lambs with restricted access to a feeding stall can be modified by the number of lambs housed in a pen.