Context-Dependent Effects of Maternal Behaviour on Lamb Growth in Tibetan Sheep

Consistent behavioural differences among individuals have been documented across many animal taxa, yet their developmental consequences in domestic production systems remain less clear. This gap is especially relevant in managed environments, where food availability and ecological constraints differ markedly from those in the wild. In this study, we assessed behavioural traits in 25 Tibetan sheep (Ovis aries) ewes and examined their associations with early growth in their lambs under semi-captive conditions on the Qinghai-Tibetan Plateau. We quantified docility, exploration, vocal responses, and several physiological measures of responsiveness in the ewes and related these variables to lamb birth weight, early weight gain, and a composite growth index. We found that maternal docility had no significant effect on lamb birth weight, whereas maternal activity, defined as locomotor movement recorded during the open-field phase, was negatively associated with offspring birth weight. One possible interpretation is that ewes showing greater locomotor activity during the open-field phase allocate energy differently during gestation, which could limit foetal growth, although this mechanism was not directly tested in this study. These results suggest that the behavioural effects on offspring development depend strongly on the production context. In this semi-captive system, greater maternal responsiveness was not associated with improved offspring performance, unlike patterns that are often observed in wild populations. This context dependence may be relevant when behavioural traits are considered in Tibetan sheep management or breeding.