19 July 2002

Dry cow management update

ENSURING cows have a good lactation starts the day cows are dried off, Shropshire-based nutrition consultant Hefin Richards told open day visitors.

"Unfortunately, dry cow management is often not good enough and on some farms it is a case of out of sight, out of mind," he said.

But the consequences of getting it wrong could be severe and expensive. Calving difficulties can be experienced, leading to stress, extra vet and labour costs, injury to cow or calf and secondary infections and metabolic problems.

Problems such as retained cleansings could see cows go down with milk fever and unfit cows would have poor appetites and not reach target milk yields, produce poor quality milk and suffer poor fertility, he added.

"Aim to have cows with a condition score of 3 to 3.5 in late lactation and maintain it throughout the dry period. Ad-lib grazing can lead to significant weight gain, so practice controlled grazing or feed an appropriate ration," he advised.

High potash levels in grass and grass silage could predispose cows to milk fever by locking up magnesium. Ideally grass intakes, particularly from heavily fertilised swards, should be limited. Low potash forages like mature hay and straw are better.

He also suggested boosting blood magnesium levels by feeding a mineral supplement or by adding magnesium chloride to drinking water. And, to maintain a cows own calcium mobilisation pathways, dry cows should not receive too much high calcium feed, such as dried sugar beet pulp.

But post-calving dietary calcium levels must be high. Dry cows should also be offered a little of the production diet for 10 to 14 days before calving. This would stimulate rumen function and prevent a sudden changeover immediately after the stress of calving. &#42

Avoid offering dry cows ad-lib grazing, says Hefin Richards.