Glycine Supplementation of Low Protein Diets in Broilers

Soybean meal and meat and bone meal are the primary protein meals used in poultry diets. The high cost of soybean meal and nutrient variability of meat and bone meal suggests the industry needs to reduce protein meal dependence. High dietary protein is also associated with high water consumption, having a negative impact on litter quality and bird health (Alleman and Leclercq, 1997). The poultry industry currently supplements diets with methionine, lysine and threonine to reduce some dependence on protein meals. There is evidence that the supplementation of glycine in poultry diets can improve performance in low protein diets (Dean et al., 2006). Glycine is involved in a diverse range of metabolic pathways, including synthesis of proteins and purines. Although glycine is categorized as a non-essential amino acid, it may become limiting under certain circumstances (Corzo et al., 2004).