Dairy farmers must body condition score their cows throughout the year, according to Dr Finbar Mulligan from the faculty of agriculture and veterinary medicine at UCD
Here in Ireland we do not condition score our cows enough, he said.
“But that’s only part of the problem – farmers must also act on the information they gather from this exercise.
Mulligan was a speaker at the recent Young Farmers’ Clubs of Ulster agri conference, held in Co Tyrone.
“At UCD, we now use a specific rule of thumb. Where lactating cows are concerned, 90% of the group should have a body condition score of between 2.75 and 3.25. For dry cows the equivalent figures are 3.0 and 3.25.
“Cows that are too thin are not securing their daily calorific requirements in full. In such instances, supplementary feed must be made available. And this principle holds equally for both dry and lactating cows.”
A degree of negative energy balance is inevitable in early lactation. But we must put strategies in place to ensure it’s marginal, of a short duration and not severe and of a long duration.
Mulligan confirmed that a dairy cow nutritional plan needs to maximise the input of grazed grass, as it’s the cheapest feed available and it’s very high in energy and protein, adding:
“Higher yielding cows are different from their lower yielding counterparts and must be fed accordingly. Early lactation cows’ milking 34L, eating 13-14kg dry matter of good quality grass, need 7-8 kg of concentrates to meet their energy requirements.
“Whereas cows milking 24L would need 2.5 to 3.5kg of concentrates if consuming 13 – 14kg of grass DM.
“However, grass silage is typically 20% lower in energy than grazed grass.”
During periods of grass shortage or if cows need to be re-housed due to adverse weather concentrate feeding rates need to be increased to reflect this.
“On average quality grass silage-only diets, cows producing 34L need 12kg of concentrates per day.
“It can prove difficult feed this level of concentrate where the intention is to supplement in the parlour only.
“Grass silage quality also has a huge bearing on concentrate feed requirements. Better quality grass silages have the potential to lower concentrate requirements by 2.5kg/head per day.”