5 June 1998

Easton

pigs feed query

MLC research suggests

Easton Lodge pig unit could

save over £10,000 in feed

costs by increased use of

phase feeding, but

preliminary trials suggest

otherwise.

Simon Wragg reports

POTENTIAL benefits of phase feed as seen by research are not being reflected on farm, according to preliminary trial results.

Easton Lodges phase-feeding trial (Livestock, Mar 13) has passed the half-way stage. About 150 pigs, finished from 73kg liveweight on a low lysine:energy ration, have been monitored and feed use, weight gain and efficiency recorded. These results are being compared to 150 pigs finished on a commercial grower/finisher ration.

At the start of the trial, unit manager Jasper Renold was sceptical about the suggested improvement in performance. "Remember, weve taken finishers off a ration with a lysine to energy ratio of 1.15g/MJ and put them on 0.96g/MJ. Normally, producers would use a higher ratio to compensate for health, appetite and digestibility."

Some of Mr Renolds scepticism is finding substance. MLC Stotfold figures suggest that pigs fed a low lysine ration should achieve daily liveweight gains of about 850g/day between 70 and 90kg, and 900g/day between 90 and 100kg.

Easton Lodge results show tremendous variations in weight gain for individual pigs of between 83 and 1.15kg a pig a day for the low lysine ration. This compares to between 125g and 1.08kg a pig a day for the commercial grower/finisher ration. "However, the growth rates of pigs on both rations have been disappointing," says Mr Renold.

Overall, average weight gains for boars fed the low lysine ration appear to be lower than those for the commercial grower/finisher ration at 740g/day versus 777g/day. However, gilt performance is better on the low lysine ration at 660g/day versus 652g/day.

"Whats becoming apparent is the environment and health status of groups of pigs may have a marked effect on their performance on the low lysine diets. What research hasnt shown so far is how big an influence those factors are on the potential benefits of low lysine diets," he suggests.

The MLC acknowledges that environment and health will affect the potential improvement in feed efficiency, as stated in its booklet Phase feeding: Effects on production efficiency and meat quality.

But other factors may also account for some of the difference between MLC and Easton Lodge results, suggests Mr Renold. For example, whereas MLC had two pigs of equal weight in a pen, under commercial conditions the average weight variation has been about 15kg a pig in pen groups of 19.

The culmination of these factors may account for the wide variation in daily lw gains of individual pigs, believes Mr Renolds. "Little information is available on the variation in growth rates of individual pigs, not only on low lysine but also commercial diets."

To help isolate other factors which might explain the variation in individual pen performance, he and the unit staff have continuously checked feeders and drinkers to ensure intakes are not being restricted. But they couldnt check whether a dominant pig was restricting access to the feed bin – that could also have been a factor.

The units nutritionist, Caroline Bevan, has been discussing ration formulation with MLC pig scientist, Pinder Gill. Palatability is a key concern with low lysine diets and her formulation uses several quality ingredients to ensure its not a limiting factor.

However, health status remains a key concern for Mr Renold. Pigs at Easton Lodge suffer various pneumonias and the next two sets of trial pigs will have been treated with an in-feed antibiotic to help control respiratory disease. It should also help control pig price.

&#8226 Final performance data from the trial will be known later this summer when farmers weekly will be discussing the results with MLC pig scientist, Dr Gill.

Jasper Renold says:"Environment and health status of groups of pigs may have a marked effect on their performance on low lysine diets