Low protein diets for pigs
New research has found that feeding pigs a low protein diet can reduce nitrogen excretion. This is encouraging for pig farmers, who will come under increasing pressure to reduce these harmful emissions.
The study involved feeding three different diets to finisher pigs of a lean genotype; pig growth and carcase quality were then measured. One diet was high in protein and the other two were low protein diets: one (LP1) which reduced nitrogen intake by 11% while maintaining dietary amino acid levels and the other (LP2) which reduced nitrogen intake by 16% but did not maintain essential amino acids in the later stages of growth.
Growth measurements showed that growth rate for pigs fed the LP1 diet was the same as the standard commercial diet but feed conversion was slightly worse.
Professor Jeff Wood from the University of Bristol explained: “This was due to slightly greater fat deposition, especially within-muscle fat which creates marbling. Growth rate was lower in LP2 pigs and they also became much fatter.
“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.”
Veterinary practices are being urged to help owners safely dispose of any unused and expired pet medicines - not just antibiotics - during November's Animal Medicines Amnesty. 
