# Ileal Amino Acid Digestibility in Various Protein Sources Fed to Broiler Chickens

## TL;DR

This study compares how well different protein sources provide amino acids to 21-day-old chickens, finding fish meal to be the most effective.

## Contribution

The study provides new ileal amino acid digestibility data for seven protein sources in broiler chickens.

## Key findings

- Fish meal had the highest ileal amino acid digestibility, followed by soybean meal.
- Palm kernel meal had the lowest amino acid digestibility among the tested protein sources.
- Fermented soybean meal showed variable digestibility, with some amino acids comparable to corn DDGS.

## Abstract

This study determines the ileal digestibility of amino acids (AA) in seven protein sources, including dehulled soybean meal (SBM), fermented SBM (FSBM), rapeseed meal (RM), copra meal (CM), palm kernel meal (PKM), corn distillers dried grains with solubles (DDGS), and fish meal (FM), in 21-day-old broilers. The results show that the FM has the greatest ileal AA digestibility among all protein sources, followed by the SBM, the RM, the FSBM, corn DDGS, the CM, and the PKM. The range of standardized ileal digestibility of AA for each source was 77.2% (Cys) to 98.7% (Lys) for the FM, 75.7% (Cys) to 89.4% (Arg) for the SBM, 69.5% (Pro) to 84.3% (Met) for the RM, 54.5% (Cys) to 83.3% (Lys) for the FSBM, 59.9% (Asp) to 85.4% (Met) for corn DDGS, 53.6% (Cys) to 80.3% (Val) for the CM, and 40.9% (His) to 82.1% (Met) for the PKM. These findings highlight the necessity of accurate evaluation of the ileal AA digestibility in various protein sources for optimal broiler diet formulation.

This study aimed to determine the ileal digestibility of amino acids (AA) in various protein sources for 21-day-old broilers. A total of 448 Ross 308 male broilers were allocated to eight dietary treatments with eight replicates in a randomized complete block design. Experimental diets included one nitrogen-free diet and seven test diets, each containing one of the following feed ingredients—dehulled soybean meal (SBM), fermented SBM (FSBM), rapeseed meal (RM), copra meal (CM), palm kernel meal (PKM), corn distillers dried grains with solubles (DDGS), and fish meal (FM), as the sole source of AA. On day 21, all birds were euthanized and subsequently ileal digesta was collected from the distal two-thirds of the ileum, extending from Meckel’s diverticulum to 1 cm proximal to the ileocecal junction. The ileal digestibility of AA in the FM was the greatest, followed by the SBM. The ileal digestibility for AA in the SBM was greater than that in the RM. The ileal AA digestibility in the RM was greater than or not different from that in the FSBM, except for Val and Pro, and superior to the CM and the PKM. The ileal digestibility of AA in the FSBM was greater than or not different from those in corn DDGS, except for Met and Cys. Corn DDGS exhibited greater or not different ileal digestibility of AA compared to that of the CM and the PKM, except for Val and Asp, and the PKM was the lowest. In conclusion, the ileal digestibility of AA was the greatest in the FM, followed by the SBM, FSBM, the RM, corn DDGS, the CM, and the PKM. Furthermore, the results underscore the necessity for continuous evaluation of ileal AA digestibility in various protein sources.