Effects of dietary fat levels on amino acid digestibility at different sites of chicken intestines

Abstract

The present study was conducted to investigate the effects of varying dietary fat levels (3%-10%) on amino acid digestibility at different sites of fistulized chicken intestines. Chickens were fistulized to either the middle part of the jejunum (MJ), the distal end of the jejunum (DJ), the middle part of the ileum, the distal end of the ileum or the distal end of the rectum. Intestinal digesta were collected from each site of the intestine, and contents of amino acids were measured. True digestibilities of individual amino acids were not affected by the sites of intestines in the 3, 5 and 8% fat groups. The true digestibility of total amino acid in intestinal digesta at the MJ was significantly lower than that at the DJ in the 10% fat group. In addition, true digestibilities of individual amino acids at the MJ tended to be lower than those at the DJ in the 10% fat group. Comparison of the data at the MJ between groups showed that the true digestibilities of total amino acid and Met in intestinal digesta in the 10% fat group were significantly lower than those in other groups. The true digestibilities of all amino acids, except for Met, in intestinal digesta at the MJ in the 10% fat group tended to be lower than those in other groups. These results suggest that dietary fat levels influence the digestion of amino acids at the proximal part of the jejunum in chickens. © 2010, Japan Poultry Science Association.