7 April 2000


RE-RANKING sires for different production systems is unnecessary, according to research work by SACs Jennie Pryce.

Evidence suggests that selecting best performing bulls is the optimum breeding policy for any production system, regardless of whether your herd is high or low feed input, said Dr Pryce.

The study compared a system in Holland, using a rocket fuel-type diet including dried grass, maize silage and up to 45% DM as concentrates, with two production systems at SACs Langhill herd, Edinburgh.

The Langhill systems varied from high input; concentrates up to 45% DM; and low input with concentrates making up 20% DM of the diet. Both used grass silage as the staple forage.

Dr Pryce concluded that re-ranking sires to take account of nutritional differences was unnecessary. But she was not convinced this story ended here, as data sets for the Dutch bulls were slightly weak.

This may have affected results and investigating a situation with stronger genetic links may be worthwhile, she added.