The effects of selection for lean tissue content on maternal and neonatal lamb behaviours in Scottish Blackface sheep

British hill sheep are required to give birth to and read their lambs under harsh extensive conditions. The aim of this study was to investigate wheth er genetic selection for increased (LEAN) or decreased (FAT) carcass lean c ontent in the Scottish Blackface breed over 7 years had affected the abilit y of ewes to rear lambs by altering the expression of maternal and neonatal lamb behaviours. The behaviour of 61 ewes (32 LEAN and 29 FAT) and their 1 19 lambs were recorded at parturition and over the first 8 weeks of life. O verall there were very few effects of selection on the behaviour of the ewe s. LEAN ewes were significantly faster than FAT ewes to start grooming thei r lambs after birth and FAT ewes tended to withdraw more frequently from th eir lambs than LEAN ewes. There was, however, a highly significant effect o f selection line on lamb behaviour. LEAN lambs were significantly quicker t han FAT lambs to perform all righting movements (median latency to stand (m ins): LEAN - 11.7, FAT = 23.4, P < 0.01), were more likely both to suck (pe rcentage that sucked: LEAN = 81.0%, FAT = 57.1%, P < 0.05), and to play wit hin the first 2h of birth. The higher rate of sucking in LEAN lambs persist ed over the first 3 days after birth (percent observations where lambs were sucking : LEAN = 7.8 (s.e. 0.8), FAT = 5.1 (s.e. 0.6), P < 0.05), when LEA N lambs were also significantly closer to their mothers than FAT lambs. The reafter, there were no significant effects of ewe or lamb line on behaviour s recorded up to 8 weeks after birth. Overall lamb mortality to 8 weeks wer e 19.3% and was not significantly affected by lamb line. However, lambs tha t were slow to perform early behaviours had a reduced survival to 8 weeks o f age. These data suggest that, although ewe maternal behaviour has not bee n significantly affected by selection for lean growth, the activity of the neonatal lamb has been affected. Lamb activity was related to lamb survival , even in our indoor lambing conditions. It is likely that the speed with w hich newborn lamb stand and suck will be even more more important for survi val under extensive conditions.