The research, which was jointly funded by Defra’s Sustainable Livestock Production LINK programme, the University of Bristol and other leading agricultural and envitonmental bodies, is encouraging for pig producers, who will come under increasing scrutiny to reduce nitrogen emissions.
Finisher pigs of a lean genotype between 40kg and 115kg were fed three different types of diet before having their growth and carcase quality measured. The research found that when pigs were fed an LP diet compared to a standard commercial high-protein diet, nitrogen intake was reduced by up to 16%.
However, researchers also found that when pigs were fed the first LP diet, amino acid levels were maintained throughout growth in comparison to the second LP diet, which did not maintain the acids in later stages of the growth. Measurements also showed that growth rates for pigs fed on LP1 were the same as those fed on a standard commercial diet, but researchers did point out that feed conversion was a little worse and costs more.
Jeff Wood, a professor from the University of Bristol, explained: “Both LP1 and LP2 regimes would cost producers more than typical higher-protein diets at present, because of the higher cost of fortifying the diets using amino acids and the poorer growth performance, especially with LP2.
"However, tighter controls on nitrogen emissions in the future may mean pig producers will need to make use of this knowledge and alter feeding regimes. And, given the LP2 diet was shown to improve pork eating quality, greater incentives for quality would make this regime more attractive.”