ANIMAL GROWTH STIMULATION BY ENZYMATIC PROTEIN HYDROLYSATE OF CHICKEN RESIDUES Authors: Nawae, W. Suntornsuk Journal: Journal of Animal and Plant Sciences (JAPS) ISSN: 1018-7081 (Print), 2309-8694 (Online) Volume: 31 Issue: 2 Pages: 369-376 Year: 2020 DOI: https://doi.org/10.36899/JAPS.2021.2.0224 URL: https://doi.org/https://doi.org/10.36899/JAPS.2021.2.0224 Publisher: Pakistan Agricultural Scientists Forum Abstract:

Frozen chicken process normally generates chicken residues as a by-product. The chicken residues contain high proteins of approximately 73%. To add a higher value to the residues, they could be hydrolysed by a protease to become peptides with functionality. The aim of this study was to produce protein hydrolysates from chicken residues to be applied in the animal feed industry as a feed ingredient for animal growth stimulatory purpose. The residues were hydrolysed by five commercial proteases: Alcalase, Neutrase, papain, pepsin and trypsin. During the hydrolysis, papain, pepsin and trypsin provided high degrees of hydrolysis which was found the highest at the end of hydrolysis, while Alcalase and Neutrase digested the residues poorly. However, cysteamine, a chemical responsible for animal growth promotion, was found at a maximum of 31 mg/ml in Alcalase hydrolysate at 6 h and Neutrase hydrolysate at 10 h. For animal growth experiments, chicken feeds supplemented with 6 h-Alcalase hydrolysate at cysteamine concentrations of 90 and 180 mg/kg diet gave significantly higher chicken growth than a controlled diet which was no hydrolysate added. Thus, chicken residue hydrolysate could have a potential use as a growth stimulant in animal feeds.

Keywords: Chicken processing waste; Animal growth stimulant; Chicken protein hydrolysates; Enzymatic hydrolysis