The amino acid composition and protein quality of various egg, poultry meal by-products, and vegetable proteins used in the production of dog and cat diets

ABSTRACT New protein ingredients are used to support pet food market growth and the development of new products while maintaining animal dietary needs. However, novel protein sources (e.g., spray-dried chicken, and (or) rice, pea, and potato protein concentrates) have limited data available regarding their protein quality. The objective of this study was to evaluate protein ingredients used in the pet food industry by laboratory analysis and a chick growth assay as a model. Following analysis for proximate and amino acid composition, chicks (six birds per pen with four pens per treatment) were fed experimental diets for 10 d. Diets contained 10% crude protein from each of the experimental protein sources (spray-dried egg—SDEG; spray-dried egg white—SDEW, spray-dried inedible whole egg—SDIE, chicken by-product meal—CBPM, chicken meal—CKML, low-temperature fluid bed air-dried chicken—LTCK, low-temperature and pressure fluid bed dried chicken—LTPC, spray-dried chicken—SDCK, whey protein concentrate—WPCT, corn gluten meal—CGML, corn protein concentrate—CPCT, potato protein isolate—PPIS, rice protein concentrate—RPCT, pea protein isolate—PEPI, soy protein isolate—SPIS, and soybean meal—SBML) along with an N-free diet (negative control). Chicks fed SDEG, SDIE, and LTPC had the highest protein efficiency ratio (PER; P