Results from our previous study demonstrated that inclusion of non-protein nitrogen (NPN) in a diet with a high essential amino acid-nitrogen:total nitrogen (E:T) ratio (i.e. limiting in total nitrogen [N]) increased the Lys requirement and maximum N retention in growing pigs. A growth performance study was conducted with grower pigs (20.2 ± 2.18 kg) fed 1 of 6 diets, with factors of NPN inclusion (no ammonium phosphate [NAP; E:T ratio of 0.35] or ammonium phosphate inclusion at 1.7% [AP; E:T ratio of 0.33]) and dietary lysine (Lys; 1.03, 1.15, or 1.27% standardized ileal digestible).
Overall average daily gain and final body weight increased with increasing Lys, but were not impacted by dietary NPN content (P > 0.05). Inclusion of NPN reduced feed intake and improved feed efficiency compared to pigs fed NAP diets (P < 0.05). Inclusion of NPN increased fecal N output (P < 0.05). Pigs fed AP diets had increased lean depth (P < 0.05). These results suggest that inclusion of NPN, as ammonium phosphate, can improve feed efficiency and increase lean depth while maintaining similar growth performance.
Inclusion of non-protein nitrogen and lysine in grower pig diets on growth performance (full article)
