The question of what is the best breed of hill sheep is one that raises much debate and a passionate defence from producers with certain breeds. It is therefore not surprising that a paper presented at the recent Teagasc hill sheep conference by researcher Frank Campion on the effect of breed on the performance of hill sheep drew close attention.
In establishing what should be the ultimate aim of any hill sheep farmer, Frank says the optimum situation is to have a flock of sheep that is suited to grazing on the hill for the maximum period of time without overgrazing and only needs to be removed for lambing and mating.
Frank says that hill sheep have evolved to survive on terrain and forage that other breeds couldn’t and, as such, are hugely responsive to improved nutrition. In recent years, breeding programmes have drifted away from this focus and while it has often led to increased output, the downside is ewes no longer suited to being run on hill terrain.
The feasibility of exploring if there are differences between breeds of hill sheep in terms of potential performance is complicated by the requirement for detailed data recording and the challenge of getting un-hefted flocks to graze hills. Research in Northern Ireland on five different crossbred ewe types including Scottish Blackface, North County Cheviot, Swaledale, Lleyn and Texel shows there were no differences between the different crossbred ewes on a lifetime performance basis.
The performance of lambs finished in lamb finishing trials in Mellows Campus, Athenry, also identified no significant difference in performance across breeds.
Detailed data was presented on a further study carried out in 2017 and 2018 on a Co Cork Teagasc BETTER farm-participating farm where two Lanark rams, a Swaledale and a Dingle Scotch ram were mated with a flock of Scottish Blackface ewes.
Data was collected over the two seasons and the lamb performance of single born lambs is detailed in Table 1. Frank says that while there were differences between the Lanark-sired lambs at birth and weaning, these were small with less than a 1kg difference in weaning weight.
Daughters of each of these rams were selected for breeding and mated as hoggets. Performance is detailed in Table 2 and Frank says that while Lanark x Scottish Blackface hoggets were 3.4kg heavier at weaning and had a slightly higher litter size the differences were biologically insignificant.
Within breed comparisons
Within any breed, there is a mixture of high-performing animals and lower-performing animals. Table 3 details the performance of three different Lanark rams on another Teagasc BETTER farm programme participant over four years.
Frank says that, on the face of it, there was very little difference in progeny performance in terms of birth and weaning weight. However, there was a 6.5% difference in lamb mortality that would in a normal system not be identified.
Frank concludes that the difference between breeds is often small and not as important as the difference within breeds and strains.
He says that the hill sheep sector needs to support and embrace the development of performance-recording groups and sales to be in a position to improve the performance and output of all hill sheep breeds and strains.