Early-Life Behavioral Time Budgets of a Local Dairy Sheep Breed in Indoor and Pasture Systems

Given the limited knowledge of early-life behavior in the Massese dairy breed, this study investigated lamb behavior from 5 to 70 days under two rearing conditions to identify age-related behavioral phases potentially relevant to weaning. Twenty-two Massese lambs were reared either in an Indoor housing system during the winter or in an outdoor Pasture system during the spring, in accordance with traditional seasonal management practices. Lambs in both systems remained with their dams with continuous access to milk. Behavioral variables, recorded weekly during daylight and expressed as relative frequencies, were analyzed against age and rearing system, using THI as covariate. Growth influenced most behaviors, with similar age-related trends across rearing systems. Suckling behavior decreased significantly with age, tending to cease at approximately 40 days in Indoor lambs and 50 days in Pasture lambs. Grooming also declined over time, indicating reduced affiliative interactions irrespective of the rearing system. In contrast, solid feed intake and rumination increased progressively, reflecting a transition toward nutritional independence. Pasture lambs engaged in moving and grazing activities while indoor lambs spent most of their time lying. These results suggest preliminary insights into a management context-associated, behavior-based weaning window in Massese lambs.