Urinary nitrogen is emitted as volatile ammonia which impacts the environment inside and outside the barn. A way to directly reduce urinary nitrogen excretion is by reducing dietary protein while still balancing for amino acids. Phase feeding may also be beneficial to match the amino acid requirements and further reduce excess dietary nitrogen. Urinary nitrogen excretion was reduced by 22% without affecting performance by a 2% reduction of dietary protein content in the grower phase. Performance or nitrogen excretion was not affected by phase feeding.
Effect of Dietary Crude Protein Content and Phase Feeding on Performance and Urinary Nitrogen Excretion of Grower Pigs (full article)
