Influence of Dietary Non-Essential Amino Acids to Lysine Ratio on Egg Performance and Body Composition of Brown-Egg Layers from 20 to 35 Weeks of Age

Limited published data are available on the ratio of digestible non-essential amino acid (DNEAA) to digestible lysine (DLys) for layers. The effect of different DNEAA-to-DLys ratios on performance parameters of Hy-Line Silver-Brown layers was studied from 20 to 35 weeks. Experimental design was randomized with ten dietary treatments of increasing concentrations of DNEAA-to-DLys ratio (10.61, 10.84, 11.08, 11.31, 11.54, 11.77, 12.00, 12.23, 12.46, 12.69). Average daily feed intake, total feed intake, laying rate, cumulative egg number, egg weight, hen body weight, feed conversion ratio, egg mass output, albumen weight, eggshell weight, yolk weight, eggshell breaking strength, eggshell thickness, carcass and feather weight, carcass protein, carcass fat, liver weight, and liver fat were recorded. Changing the DNEAA/DLys ratio did not affect production parameters. Yolk and yolk-to-egg weight decreased with an increase in DNEAA/DLys ratio, while albumen-to-yolk and albumen-to-egg weight increased. The DNEAA/DLys ratio did not affect carcass or liver composition, but liver and liver-to-body weight (%) decreased as the DNEAA/DLys ratio increased. Hy-Line Silver-Brown layers during peak production sustained egg production and quality even on the lowest ratio in this study. Low DNEAA/DLys ratios increased liver fat deposition.