Increase use of pulses for ‘greener’ pigs, trial advises

Research funded by Defra and Bpex has found that increasing the use of home-grown pulses in pig feed would increase the sustainability of the UK pig industry without compromising on growth performance or slaughter measures.

The long-term ‘green pig’ trial, which was hosted on a commercial scale by Midland Pig Producers (MPP), found that home-grown legumes (peas and faba beans) can provide a viable alternative to imported soya beans, reducing the UK pig industry’s part-reliance on foreign imports of soya bean meal (SBM) and rising feed prices.

The trial assessed the potential of using home-grown peas and beans in growing and finishing pig diets, looking at three different diet formulations, and their effects on body weight gain, feed conversion ratios and back fat depth at slaughter. It found comparable rates between the 30% pea-based and 30% faba bean-based diets when compared with the SBM control.

Currently, producers typically use around 5-11% of legumes in pig feed. However, the study concluded that the ratio of peas and beans used in UK pig-feed can be increased from its current maximum level of 15%. It also said there was no discernible difference between using peas or beans, suggesting that producers could choose whichever legume suits them better.

However, Anna Davis, environment projects manager at Bpex, said that while the findings show the potential of legumes in UK pig production, until peas and beans yields can be improved, it is unlikely to be widely adopted in the immediate future. She said that farmers cannot guarantee the crop, so they are less inclined to grow it on a large scale.

Davis said: “There are producers already using this method, but it depends on the individual producer’s situation. It’s not at the stage of being used nationwide, but for a producer who grows, mills and mixes their own feed on farm, it could really reduce feed costs.

“It’s possibly more useful for the organic sector, as the rules on soya that can be used as feed are more stringent."

However, she said that there is an opportunity for the retail sector, which wants to raise its credentials by increasing low-soya pork, but that this was the hardest part of the food chain to reach. She said that producers, feed manufacturers and retailers need to work together.

“It’s a vicious circle. Feed manufacturers won’t produce it until the producers want it, and producers won’t push for it until they know that it is available.”

Martin Barker, MD of MPP, agreed that there was potential for creating a price premium for a more environmentally friendly product, but that there would need to be incentives from the market. However he said that for those producers who use rotation system to create their own feed, 'in cashflow terms, it takes  out the volatility of feed prices."

The research formed part of a £1.5m project, launched in 2008 by a consortium, whose members include Bpex, the Scottish Agricultural College (SAC), Quality Meat Scotland (QMS), the University of Nottingham, the National Institute of Agricultural Botany (NIAB), MPP, BOCM Pauls, Evonik-Degussa, Harbro, Premier Nutrition Products, the Soil Association, Union Nationale Interprofessionnelle des Plantes Riches En Protéines (UNIP) and the Processors and Growers Organisation (PGRO).

PGRO, the UK research and levy body for legumes, is working on improving the genetics of the crop to improve yield, which would make them viable for animal feed on a larger scale. Currently the vast majority of peas and beans grown in the UK are grown for human consumption and would be too costly to feed to animals.

Soya is the primary source of protein used in pig feed, contributing 70% of protein and accounting for 30% of the feed by volume. Around 2m tonnes of SBM comes into the UK each year, with 200,000-300,000 tonnes used in pig feed.