5 December 1997

Target growth with accurate analysis

By Jonathan Riley

WINTER rations for growing cattle can only be formulated accurately if silage is analysed, according to Hants beef and cereal producer Robert Shepherd.

All progeny from Allenford Farms 350 Simmental cross sucklers are offered silage ad lib.

"Unless you know what silage is contributing to the diet you cannot formulate a cost-effective winter ration that will promote target growth rates for beef," he says.

A single cut from Italian ryegrass leys provides the entire 900t needed to take the growing cattle through the winter. "Although this years silage crop is good quality, dry matter is low. "This means cattle may not be able to extract enough nutrients to support our target growth rates," explains Mr Shepherd. He plans, therefore, to provide some straw for the growing cattle to slow the passage of silage through the gut and allow the rumen more time to breakdown feed.

"About 35 bulls are finished and these are weaned at about 250kg to 300kg at 250 days old. "From housing we must achieve a growth rate of 1.5kg a day to reach target sale weights of 550kg to 600kg by May.

"Maize gluten and rolled barley will be fed to appetite here, and regular weighing will enable us to adjust rations to maintain optimal growth rates.

Newly-weaned steers and heifer calves will receive silage ad lib and 1kg of maize gluten initially to sustain store growth rates of 0.7-0.8kg and achieve turnout weights of 380kg in March.

Steers and heifers in their second winter are offered ad lib silage as the basic ration. The aim for beef heifers is to finish them as quickly as possible to hit the Christmas market.

Depending on silage analysis and growth rates – which are calculated after regular weighing – heifers are offered silage and about 1.5kg of maize gluten a head a day.

Steers are also fed maize gluten plus about 2.5kg of rolled barley to achieve growth rates of 1.2kg to finish from February onwards between 550kg and 600kg.

"This ration is geared to finishing steers after they have qualified for the second special premium payment," says Mr Shepherd.

For cows, stubble turnips and straw make up the winter ration as he believes that feeding silage would not be cost effective when cows only require low quality feeds.

"Pregnancy diagnosis and condition are the key pointers for winter feed management with the sucklers," says Mr Shepherd. "PDing cows means we know immediately which cows are barren. We can, therefore, cut feed costs and we dont waste time waiting to see if cows will calve in the spring," he says.

Blood testing carried out last spring has also helped with ration formulation because it identified a copper deficiency which has been corrected with a specific mineral mix. This has led to the best pregnancy rate to date at 90% in calf.

After weaning, which is carried out before cows begin to lose condition, cows are split into two groups according to condition. The stubble turnip area grazed is then adjusted using temporary electric fencing according to condition score, with thinner cows receiving more barley straw and a larger grazing area to boost condition.n

Silage analysis ensures cattle at Allenford Farms are rationed accurately.