Thanks for your contribution.
As a preamble, glycine is more than protein synthesis. This amino acid is involved in many physiological systems cutting across gut and immune health, digestive physiology, bone and cartilage formation, blood synthesis, bile accretion. Collagen is used alongside P and Ca in bone matrixes. While the significance of glycine is that it constitutes about 30% of native amino N matter in collagen. There is ample prove also that DNA/RNA synthesis demand glycine availability. Glycine of course is a precursor of serine and indirectly a precursor of cysteine. Glycine affects cellular methionine turnover, if one considers the folate remethylation pathway. Threonine catabolism also yield glycine, so that it has a critical role in overall protein an amino acid homeostasis. But for space/brevity one can go on and on. If you have these multiple involvements the likelihood (which informed our hypothesis) is that dietary glycine supplementation will benefit not only efficiency of utilisation of key nutrients but also economic performance at whole animal level. Therefore in our study we placed a matrix demand on the nutrients you stated, and the result was indeed amazing.
In fact we think this amino acid is a dietary essential amino acid to attain optimum poultry performance, contrary to old school amino acid categorization.
When using Ideal Protein for layers with the amino acids, lysine, methionine, value, the so one, arginine, and tryptophan then glycine must be used to equal glycine in a 16 % crude protein diet to provide enough nitrogen for non essential amino acids.