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

Summary

Organic pig producers lack tailored nutrient guidelines, so this study tested five SID lysine levels to find a physiologically optimal supply. Across two balance trials, higher lysine increased nitrogen intake and urinary N losses but did not improve N retention, and pigs did not compensate by eating more grass–clover silage. Overall, lysine levels above the lowest tested mainly raised nitrogen excretion without supporting additional protein deposition, underscoring the need for organic‑specific amino‑acid guidelines.