Effects of dietary lysine supply on nitrogen utilisation in organic growing–finishing pigs

Summary

Organic pigs were fed five diets differing in SID lysine to evaluate effects on nitrogen utilisation. Increasing lysine raised total nitrogen intake and urinary nitrogen losses in both growth stages. Nitrogen retention did not improve at higher lysine levels and even declined in heavier pigs. Roughage intake did not adjust to dietary lysine, offering little compensatory amino acid supply. Overall, lysine levels above the lowest treatment increased nitrogen excretion without enhancing protein deposition, underscoring the need for organic‑specific amino acid guidelines