Estimating requirements for apparent faecal and standardised ileal digestible amino acids in laying hens by a metaanalysis approach

Dit rapport geeft een update van de behoefte aan aminozuren (lysine, methionine+cysteine, threonine en tryptofaan) van leghennen, zowel op basis van schijnbaar fecaal verteerbare als gestandaardiseerd ileaal verteerbare aminozuurgehalten van het voer. Hiervoor is een meta-analyse uitgevoerd op peer reviewed dosis-response studies. Studies moesten voldoen aan een vooraf bepaalde set van criteria, voordat ze bij deze analyse betrokken werden.The aim of the present study is to update the requirements for the essential amino acids of laying hens, both on a AFD and SID basis, by performing a meta-analysis on dose-response studies used to derive requirement values for essential amino acids (lysine, methionine+cysteine, threonine and tryptophan) in laying hens as presented in the literature. In this meta-analysis, the data are fitted by use of the Wood equation (see paragraph 2.4). The amino acid intake levels for realizing maximal rate of lay, egg mass and feed efficiency are provided. The amino acid requirements for use in practice are based on the amino acid intake levels at which 95% of these maximum responses were reached