The Effects of Pair versus Individual Housing Preweaned Dairy Calves on Behavior, Growth, and Acquired Immunity

Our objective was to determine the effect of pair versus individual housing of calves on growth, behavior, and immunity. At 5 ± 1 d relative to birth, calves with successful passive transfer of immunoglobulins from colostrum were blocked by sex and birth date. Housing treatment was assigned to either pair (n = 14) or individual (n =14) housing. Calf pairing was implemented by combining two individual pens. One paired calf served as the focal calf and the other imposed treatment. All data were collected from the focal calf in pair housing. Control calves remained individually housed. ADG, DM, feed refusals, and growth at weaning to one-week-post weaning did not differ between housing treatments. Paired calves spent more time awake, and increased standing time. Individual calves projected their head out of the pen more frequently. Hunger and anticipation behaviors did not differ between housing treatments. These data suggest paired calves were more active during the milk feeding stage. The increased activity of pair housed calves may suggest improved welfare of preweaned calves. IgG and IgM ELISA units to keyhole limpet heomocyanin did not differ between housing treatments. IgG ELISA units at d 14 were lower than d 3, 28, and 35 in all calves. IgM ELISA units were highest at d 3, but continued to drop thereafter. The stimulation index for delayed hypersensitivity to Candida albicans did not differ between housing treatments. However, they did increased over time, and peaked at 24 and 48 h post C. albicans injections. Pain sensitivity did not differ between housing treatments, however calves increased sensitivity at 27, 51, and 75 h, relative to disbudding. Pair housing dairy calves during the preweaned period did not negatively affect the immune development of dairy calves or pain from disbudding. This suggests social housing calves early in life does not suppress the immune system, or increase pain sensitivity after disbudding.