Determination of Ileal Amino Acid Digestibilities of Some By-products for Chickens

Abstract

The aim of this study was to determine the standardized ileal digestibility of amino acids in six by-product ingredients for broiler, i.e., copra meal, rapeseed meal, feather meal, hydrolyzed poultry meal, meat and bone meal, and shrimp head meal. Luong Phuong chickens at 35 days of age were used in the trials. Dietary protein in all assay diets was supplied solely by the test ingredient. In the case of protein-rich ingredients, dextrose was added to assay diets to obtain 20% of crude protein. Standardized ileal amino acid digestibilities were calculated by correcting the apparent ileal digestibility coefficients by basal endogenous amino acid losses. Results of study showed that the variation in ileal digestibility coefficients of amino acids was low in rapeseed meal and high in copra meal. Among animal protein meals, the lowest variation of digestibility among amino acids was observed in shrimp head meal. The high standardized ileal digestibilities of Arg, His, Leu + Ile, Thr, Trp, Val, and Phe were observed in hydrolyzed poultry meal and shrimp head meal. Meanwhile, the standardized ileal digestibility values of Lys, Thr, and Trp in feather meal were very low. Meat and bone meal and feather meal was the two least digestible amino acid ingredients.