28 November 1997

Plugging the energy gap

DAIRY cow yields are increasing twice as fast as the increase in dry matter intake needed to support that yield; plugging this energy gap depends on improved feeding techniques and prediction of intake as a genetic selection tool.

So the Holstein Friesian Societys Mike Coffey claimed at a series of its Dairy Roadshows. He said that the biggest factor in helping these animals survive, and achieve good welfare and fertility, is securing high intakes on-farm and managing condition score.

"Friesian cows put on weight in late lactation and lose it in early lactation. But a Holstein cow doesnt respond well to this type of treatment. Producers must get used to managing these cows at a lower condition score, but keeping it more stable."

Mr Coffey recommended aiming for a condition score of three at calving, dropping to a minimum of 2.5 halfway through lactation, and back to three at drying off.

Cows managed for a lower condition score at calving would have a higher appetite to support peak yields. But it would be important to ensure these cows with little body reserve could eat as much as possible. This required adequate feed space, pushing up feed frequently, rationing correctly, feeding mixed forage diets and having well lit feeding areas, added Mr Coffey.

He believed that when condition score is related to yield and some linear type traits, it should allow a prediction of dry matter intake.

"For example, if we had two equal production bulls, the daughters with the highest condition score of the two must be eating more food and better at avoiding weight loss."  

Mr Coffey, therefore, believed that selecting for condition score, after correction for production, would mean selecting for intake.

Intake prediction is being researched at SACs Langhill Farm, Edinburgh, as part of the sustainable breeding goals project, along with liveweight prediction from linear type traits. &#42

Improved feeding techniques are needed to ensure modern dairy cows can eat enough to support their increased drive to produce milk.