Flock genetics has a very major effect on labour requirements, and the level and quality of output from the hill sheep sector. A recent hill sheep study undertaken in Northern Ireland showed that ram breed substitution could increase output per ewe by up to 24% with concomitant improvements in carcass quality (Carson et al., 2001a&b). Major opportunities now lie in improving the genetic potential of hill ewes, particularly as all ewe genotypes will be eligible for full hill support payments.
Currently in Northern Ireland, hill sheep flocks consist mainly of purebred Scottish Blackface and, to a lesser extent, Wicklow Cheviot ewes. Using purebreds rather than crossbred ewes, means that the potential benefits of heterosis are not exploited in harsh hill conditions where they are likely to be of greatest benefit. Crossbreeding could be used to take advantage of breed differences in genetic merit for different traits (e.g. hardiness, ease of lambing, carcass traits) and the benefits of heterosis. Thus in extensive hill systems, including those moving to organic systems, the opportunity to improve the hardiness characteristics of the ewe and lamb survival are key factors which could be improved by crossbreeding, greatly reducing labour requirements.
In other hill systems there may be opportunities to use crossbred ewes with improved growth and carcass traits to improve the level and quality of lamb output. In all systems ewe fertility, ease of lambing, and lamb viability traits are likely to greatly benefit from crossbreeding.
Annett, R. , Carson, A. F. , Dawson, L. E. R. , Irwin, D. , Kilpatrick, D. J. (2011). Effects of breed and age on the performance of crossbred hill ewes sourced from Scottish Blackface dams. Animal, 5(3):356-366
Annett, R. , Carson, A. F. , Dawson, L. , Irwin, D. , Gordon, A. W. , Kilpatrick, D. J. (2011). Comparison of the longevity and lifetime performance of Scottish Blackface ewes and their crosses within hill sheep flocks. Animal, 5(3):347-355
Annett, R. , Carson, A. F. , Dawson, L. , Kilpatrick, D. J. (2010). Effects of dam breed and dietary source of n-3 polyunsaturated fatty acids on the growth and carcass characteristics of lambs source from hill sheep flocks. Animal, 5:1023-1035
Dawson, L. E. R. (2004). Crossbred ewes for the hill sector - The way forward?. Farming Press, July 2004