Lambs cope better with gradual weaning and definitive maternal separation when housed with known-adult companion ewes (2025)

Titto, C. G., Pantoja, M. H. de A., Martins, M. M. et al.

Abstract

Gradual weaning reduces lambs’ distress during definitive maternal separation by progressively decreasing milk intake and maternal contact. However, repeated temporary separation during gradual weaning, followed by definitive separation, remains stressful and negatively impacts lamb behavior, immune function, and overall physiological balance of the animal. The aim of this study was to determine whether housing lambs with familiar adult non-lactating ewes during gradual weaning and after definitive maternal separation would reduce distress-related behaviors and affect body weight and parasitic infection, assessed using the FAMACHA score. Twenty-eight single-born lambs, aged 78–95 days, were assigned with their mothers to two experimental groups: A) one group was housed with three known-adult companion ewes that were not nursing from Day −10 (Day 0: definitive maternal separation) until the end of the experiment (n = 14); B) the other group was housed only with their mothers (n = 14). Gradual weaning was conducted for all lambs from Day −5 to Day −1, during which lambs were separated from their mothers daily from 08:00 h to 14:00 h. During ewe-lamb separation, mothers were relocated to a minimum distance of 150 m. Lamb´ behaviors (vocalizing, pacing, lying down, walking and grazing) and the distance to the closest known-adult companion ewes to the lamb were recorded from Day −8 to Day 3. In both groups, the distance between each lamb and its mother was also recorded from Day −8 until Day −1. Body weight and FAMACHA scores were recorded on Days −11 and 5. The presence of known-adult companion ewes reduced the frequency of vocalization, pacing and grazing, maintained the frequency of lying down stable, and increased the distance between lambs and their mothers during gradual separation. After definitive maternal separation, lambs housed with known-adult companion ewes vocalized and paced less, and grazed and walked more than lambs housed alone. Lambs allocated with known-adult companion ewes also exhibited lower FAMACHA scores after definitive maternal separation. No differences in initial and final body weights were observed between groups. The early introduction of a known-adult companion ewes before gradual weaning reduced distress-related behaviors and improved the health status of lambs following definitive maternal separation.