Interpretive Summary: Effects on nitrogen balance and metabolism of branched-chain amino acids by growing pigs of supplementing isoleucine and valine to diets with adequate or excess concentrations of dietary leucine
By Anne Zinn
A recent study published in the Journal of Animal Science aimed to determine if isoleucine and valine supplementation would overcome the detrimental effects of excess dietary leucine on nitrogen balance and metabolism of branched-chain amino acids in growing pigs. Leucine is a key regulator that stimulates catabolism of branched-chain amino acids in skeletal muscle and liver. If diets fed to pigs contain excess leucine, catabolism of all three branched-chain amino acids may increase, which can reduce feed intake and growth performance of pigs, a possible result of the imbalanced supply of branched-chain amino acids that result from increased metabolism of valine and isoleucine.
Results of the current study revealed that excess dietary leucine reduced the nitrogen retention and increased plasma urea nitrogen in growing pigs, but also indicated that the valine supplementation to excess leucine diets may increase the efficiency of amino acid utilization for protein synthesis as indicated by reduced plasma urea nitrogen.
The full paper can be found on the Journal of Animal Science webpage.