8 March 2002

How to meet target weight

Setting realistic livestock production targets and

how to achieve them were the twin themes of a

Trident Feeds sponsored open day at ADAS Rosemaund

in Herefordshire last week. Robert Davies reports

KNOWING optimum growth rates required to meet target marketing weights and dates with primestock of the desired conformation and fat class is the first step to maximising profit on livestock farms.

Setting the scene during the days seminars, ADAS senior consultant Kate Phillips insisted that animals produced must match the breed, type and sex demanded by the market.

In addition, the best possible use should be made of home-grown feeds to achieve these aims economically, which necessitated costing out all elements of rations.

Those doing their sums this year would know that the shortage and high price of straw made each mega joule of energy provided by it 1.5 times more expensive than from rolled barley.

But work at Rosemaund had indicated the scope for substituting ration components, like the 1m tonnes of soya bean meal imported every year. Young bulls fed ad-lib maize were offered 2kg/day of one of four mixes containing barley and either soya, lupins or a combination of the two.

She explained the best daily growth rate of 1.05kg was achieved when protein came from a blend of 77% soya and 33% lupins. Including 67% lupins produced a gain of 1kg/day, while feeding only barley and lupins gave a 0.95kg/day gain, or only 0.04kg less than when soya alone was used.

"Various combinations of high quality feeds can be used as alternatives to more conventional diets. These can prove to be economical, particularly when there are good storage facilities for bulk feeds on farm."

But care must be taken to counter any potential mineral, trace element or vitamin deficiencies. Mrs Phillips also recommended keeping a keen eye on formulations when buying in compound feeds and asking searching questions about unfamiliar ingredients.

ADAS senior researcher Dennis Chapple added the farm was evaluating simple home-mix for ewes fed ad-lib straw in late pregnancy. A blend of rolled wheat and rapeseed costing £110/t was used as the control.

Another group of twin bearing, March lambing ewes were being fed a 60:40 mixture of maize and sugar beet with an ME of 13.6 and 18% protein. The third supplement contained molassed sugar beet feed and soya, and had an ME of 12.7 and 18.4% protein.

The final group were on the moist feed Praize, Trident Feeds 4:1 blend of pressed sugar beet pulp and distillers maize. Mr Chapple said this was fed at twice the rate of the others to provide similar levels of protein and metabolisible energy.

He also reminded open day visitors that straw quality was more important than straw type. At least 1.5kg/head a day should be fed to allow for selection and the waste that ended up as bedding. The rate of supplementary feeding should be increased gradually from eight weeks before lambing and ewes should be given time to adapt to any diet changes.