Gentle vs. aversive handling of pregnant ewes: I. Maternal cortisol and behavior

Abstract

The aim of the experiment was to study the effects of aversive vs. gentle handling in late pregnancy on maternal behavior of ewes. Sixteen Norwegian Dala ewes bearing twins were subjected to 10min of either gentle (GEN — soft talking and calm behavior) or aversive (AVS — swift movements and shouting) handling twice a day during the last 5weeks of pregnancy. Salivary cortisol was recorded before and after treatments. The following behaviors were recorded post-partum in the ewes: grooming duration, number of vocalizations and in the lambs: number of vocalizations, latency and duration of standing, latency and duration in udder-directed position. The ability of the ewe to follow her lamb carried away by a human was scored on day 1 and 7. After the treatment sessions, cortisol levels tended to increase in AVS ewes but not GEN ewes. At parturition, AVS ewes groomed their offspring for a longer duration than GEN ewes. AVS lambs tended to be heavier than GEN lambs at 24h of age. Follow Scores from GEN ewes were higher than for the AVS ewes at day one, but no difference between treatment groups was detected after one week. These results show that aversively treated ewes increased their grooming behavior towards their offspring, but that fear of humans disrupted their ability to follow their lambs closely when carried away by a human. We conclude that the type of handling of ewes during pregnancy may have some impact on important maternal behaviors.