Consultants and nutritionists should advise producers on what ration is needed to sustain healthy cows, warned Wisconsin, USA independent nutritionist Blaine Ellison.

“Nutrition should not be the limiting factor on a unit.

When we are feeding cows properly we are not breaking them and production will follow,” he said.

The lactation curve began in the dry period, he said.

“When cows are too thin the lactation curve will suffer.

You can alter condition score by 0.25 points over 60 days, but that needs fixing in the last 150 days of lactation and not the dry period,”

said Dr Ellison, who has responsibility for feeding about 50,000 cows, including one 10,000-cow herd.

“Remember, a broken cow gives no profit.

As cow numbers increase so does competition at the feed fence and you can start to see more ketosis.

Why not kick dry cows outdoors and give fresh cows more space?

And don’t think a cow can eat significantly more the day after calving as she could the day before.

“You must also pay more attention to heifers.

They cannot compete with large groups of cows at the feed fence, so consider having a separate fresh heifer group when space and management allows.

They will give you typically 3kg more milk a day at 80% stocking density rather than 100% and even more when not competing with cows.”