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 10 min of either gentle (GEN--soft talking and calm behavior) or aversive (AVS--swift movements and shouting) handling twice a day during the last 5 weeks 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 24 h 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.
Subject(s)
Handling, Psychological , Hydrocortisone/metabolism , Maternal Behavior/psychology , Age Factors , Animals , Animals, Newborn , Body Weight/physiology , Female , Goats , Humans , Parturition/physiology , Parturition/psychology , Pregnancy , Reaction Time/physiology , Saliva/metabolismABSTRACT
We compared the effects of aversive and gentle handling in late pregnant ewes on fearfulness, heart rate variability and spatial learning in lambs. Twenty-four Norwegian-Dala ewes were studied. Ewes were subjected to gentle (i.e. soft talking and calm behavior) or aversive handling (i.e. swift movements and shouting) for 10 min twice a day during the last five weeks of pregnancy. Lambs from aversively (AVS) or gently (GEN) treated ewes were tested at 4 weeks of age. Lamb behavior was recorded during a) a human approach test, composed of 4 min of isolation and 4 min of exposure to an unfamiliar human, b) an umbrella startle test followed by 5-min recording, and c) two repetitions of a maze test. In addition, heart rate variability was recorded telemetrically before and after the human and startle tests. The baseline heart rate variability measures suggested a lower influence of vagal stimulation in AVS lambs. In the human approach test, AVS lambs vocalized and explored the environment less, and were slower to approach the human. They also tended to have higher flight distances during the startle test than the GEN lambs. The prenatal treatment had no significant effect in the maze test. In conclusion, we showed that aversive handling of pregnant ewes increased fearfulness and reduced vagal tone in their progeny compared to GEN lambs. These effects can have consequences for how lambs cope with rearing conditions.
