EFFECTS OF MATERNAL GENOTYPE AND BEHAVIOUR ON THE BEHAVIOURAL DEVELOPMENT OF THEIR OFFSPRING IN SHEEP

AbstractSignificant breed differences in grazing, activity, social and other affiliative behaviours are known to exist in sheep. The roles of maternal and offspring genotype in determining the development of breed-specific behavioural differences in lambs were investigated using embryo-transfer. Two breeds of sheep (Suffolk and Scottish Blackface) were chosen as they differ markedly in social and affiliative behaviours. Sixty ewe-lamb pairs (15 each of the four combinations of ewe and lamb) were observed over the first 3 days after lambing, then when the lambs were aged between 2-5 months old and during the first 6 weeks after weaning. Lamb breed was the main factor affecting lamb activity at birth and play behaviour over the first postnatal days, with Blackface lambs being significantly more active than Suffolk lambs. Lamb sucking behaviour during this period, however, was significantly affected by ewe breed with a higher frequency of sucking interactions observed with Suffolk ewes. When out at grass the two breeds of ewe differed in their use of the field, with Blackface ewes using upland areas whilst Suffolk ewes were found almost exclusively in the lowland parts. Ewes also differed in their spatial relationship to their lamb, with Blackface ewes maintaining a closer relationship to their lamb than Suffolk ewes, regardless of lamb breed. Blackface ewes were also more active than Suffolk ewes and were more frequently observed grazing. The breed of their mother significantly influenced the behaviour of the lambs, and their spatial relationships to other sheep, both before and after weaning. Lambs with Blackface mothers were more active than lambs with Suffolk mothers and this difference persisted after weaning. Blackface-reared lambs also had a shorter nearest neighbour distance after weaning, aggregated into smaller subgroups and were significantly more likely to be in upland areas of the field, regardless of lamb breed, than lambs reared by Suffolk ewes. Maternal influence, therefore, plays an important role in shaping the behaviour of their offspring in sheep, although neonatal lamb activity is not affected by maternal behaviour.