Biological evaluation of the effect of processing conditions on feather meal amino acid digestibility.

Abstract

Feathers were autoclaved for 30, 50 or 70 min without addition or with 0.4% sodium hydroxide or 0.4% proteolytic enzyme. Groups of 7 young male chickens were given feather meal as their only feed in 3 doses at intervals of 3 h. Excreta were collected during 36 h from the first intake of feather meal. Amino acid concentrations in ileal digesta were estimated 2.5 h after the last intake of feather meal and plasma amino acids were estimated 1 h after the last intake. There was considerable variation in true digestibility between individual amino acids ranging from 36% for aspartic acid to 87% for isoleucine. Mean true digestibility of lysine was 49, histidine 53, methionine 63 and cystine 49%. Amino acids were increased in the ileum and decreased in plasma as processing time of the feather meal was increased. It was concluded that quantitative digestibility estimations by excreta analysis of the individual amino acids have to be used for evaluation of quality of feather meal. (Abstract retrieved from CAB Abstracts by CABI’s permission)