2 June 1995

FEEDING ANSWERS SOUGHT

Dairy cow research is set to take a giant leap forward if a £2m multi-centre, three-pronged project lines up to expectations.

Allan Wright reports

CAN dairy cows balance their own rations to match different protein and energy requirements during various stages of lactation? And do high genetic merit animals choose different feeds to their low merit contemporaries?

Answers to these questions should come from a four-year project at the Scottish Agriculture Colleges Langhill Dairy Research Centre, Edinburgh.

The £367,000 cost is being met by the Biotechnology and Biological Sciences Research Council (BBSRC) and BOCM Pauls and the research team headed by Dr John Oldham, head of SAC genetics and behavioural sciences.

"Genetic gain in pigs and poultry has been so dramatic that nutritionists demand to know the genotype before advising on feeding," says Dr Oldham. "That does not happen yet with ruminants."

He cites work which has shown that growing pigs will choose a mix of protein and energy feeds to suit the needs of different genotypes. Research has also shown that growing sheep will choose feed intakes for optimum growth while avoiding excess protein in their diet.

"For the first time, we are now go-ing to study the interaction between genotype and nutrition in the dairy herd by sampling average and top gene-tic merit cows to see what they want to eat at various stages of lactation," he says.

Thirty-six animals will be involved in trials each year, split between average and high genetic merit. They will have free choice access to two complete diet feeds. These will have the same forage to concentrate proportions but a different protein to energy ratio within the concentrate.

New, automatic feed intake recorders will not only measure intake of each cow but frequency of feeding and how feeding behaviour is linked to twice-a-day milking.