15 December 1995

Dairy protein shock

ONE in 10 blood tests from UK dairy cows on full winter rations show significant rumen degradable protein (RDP) shortages. That is the finding of the Dalgety Dairy Herd Health and Productivity Service run with the University of Edinburgh.

Shortages showing

DHHPS vet David Whitaker says: "Shortages are showing even on herds getting good quality grass silage which should contain plenty of protein. It is possible that silage made in very dry conditions could contain a higher proportion of protein as digestible undegradable protein (DUP) rather than RDP."

Dr Whitaker says that milk yields could be hit and the risks of offering low RDP forages could be greater still with grass silage in short supply.

"Improving the protein balance could lead to improvements in milk yield of up to three litres a day. But, if RDP is short, additional DUP will be an expensive failure.

"An accurate diagnosis is crucial. This can be done in a day or two with a blood test."

"For dry cows maintained on straw as the sole forage source it is essential straw is properly balanced with RDP," says Dr Whitaker. "That will avoid detrimental effects on both productivity and fertility in the next lactation."