Ewes are more attentive to their offspring experiencing pain but not stress
Publication Type: |
Journal Article |
Year of Publication: |
2011 |
Authors: |
Sophie Hild, Corinna C. A. Clark, Catherine M. Dwyer, Joanna C. Murrell, Mike Mendl, Adroaldo J. Zanella |
Publication/Journal: |
Applied Animal Behaviour Science |
Keywords: |
lambs, lps, maternal behaviour, pain, stress, welfare |
ISBN: |
0168-1591 |
Abstract:
The goal of this experiment was to detect if maternal care by ewes could be effective in mitigating psychological or physiological stress or pain in their offspring. We hypothesised that ewes are able to recognise when their offspring undergo an adverse experience and will adapt their maternal behaviour to buffer the effect of such events. Thirty-one pairs of 2-day-old lambs were subjected to a baseline clinical examination that consisted of measuring body temperature, bodyweight and mechanical pressure pain threshold. On day 3, physiological or psychological stress was applied to one sibling, induced by intravenous injection of LPS or social isolation for 10 min after a further baseline clinical examination, while the other twin experienced only the baseline clinical examination. On day 4, one sibling experienced pain induced by tail docking (females) or tail docking and castration (males) after the baseline clinical examination, while the other twin experienced only the clinical examination. Maternal sniffing, licking, glancing and nursing were recorded for 20 min post-treatment on each day. On day 4, pain behaviours of the treated lamb were also recorded, as well as mother-young inter-individual distances. Measures obtained on day 3 indicated no difference in maternal behaviour directed to the offspring that experienced the stress treatments compared to their twin lamb or to the same lamb on day 2. On day 4, ewes showed more attention to the lamb that had experienced the pain stimulus compared to the other twin lamb and to the same lamb on day 2. The amount of maternal behaviour observed on day 4 was positively correlated with pain behaviours expressed by the treated lamb, suggesting that the ewe was responding to the behaviour of the lamb. We cannot confirm whether the change in maternal behaviour may have buffered the effects of the painful stimuli but the possibility that such a phenomenon occurs later cannot be ruled out.