Effect of individual or paired housing during post-weaning on feed intake, growth rate and behaviour of lambs

The aim of this study was to compare the behaviour and weight gain of weaned lambs penned either in pairs or alone, with visual and tactile contacts between pens. A 2 × 2 factorial experiment was conducted over seven weeks. Forty-eight Dorset lambs (twenty-five females and twenty-three males) were randomly distributed among pens. All pairs were non-twin lambs of the same sex. They were fed haylage (48.9% of DM) and a commercial pelleted feed both provided ad libitum. Weight of lambs was recorded at d0 and then weekly until d49. Consumption of dry matter and average daily gain (ADG) were also recorded. Lamb postures, activities and total bleats were directly observed in the morning and in the afternoon on six different days (d1, d2, d5, d12, d19, d26). On d1, observations were done only in the afternoon. For paired lambs, data were averaged by pen. Lambs penned alone were less active, slept more (P < 0.03) and walked less (P < 0.001) than paired lambs. Total bleats were not affected by housing treatment or sex, but were significantly higher for the first two days (P < 0.0001). Lamb growth performance was unaffected by the type of housing (P > 0.05). There was a significant difference in ADG (P < 0.001), total gain (P < 0.001), kg concentrate kg⁻¹ gain (P < 0.05) and final body weight (P < 0.05) in favor of males as compared to females. Our results suggest that a housing system in which individually raised lambs are allowed visual, tactile, and auditive contact with each other, compared to lambs housed in pairs, does not impact negatively on their growth and behaviour.