Ileal digestibility of amino acids of pea protein concentrate and soya protein sources in broiler chicks

Abstract

A trial was conducted to determine the coefficient of ileal apparent digestibility (CIAD) and ileal true digestibility (CITD) of amino acids of raw pea protein concentrate (PPC), soya protein concentrate (SPC), soya bean meal (SBM) and fullfat soya bean (FFSB) in 21-day-old broilers. Four diets were formulated based on maize starch and sucrose and with the test ingredient as the unique source of dietary protein (200 g/kg). In addition, a nitrogen free diet was formulated to estimate the basal ileal endogenous losses of amino acids. Chicks were fed a commercial maize-SBM diet from 1 to 17 days and then, their respective experimental diets from 18 to 21 days of age. All feeds were offered ad libitum in mash form and each treatment was replicated 6 times. Chicks fed SPC and SBM had higher CIAD of arginine, methionine and valine than chicks fed PPC ( P < 0.05) with chicks fed FFSB being intermediate. In addition chicks fed SPC, SBM and FFSB had higher CIAD of threonine and isoleucine than chicks fed PPC ( P < 0.05). Chicks fed SBM had higher CITD of crude protein and leucine than chicks fed FFSB ( P < 0.05) with chicks fed PPC and SPC being intermediate. Also, chicks fed SBM had higher CITD of methionine ( P < 0.01) than chicks fed PPC with chicks fed SPC and FFSB being intermediate. It is concluded that apparent ileal digestibility of amino acids are higher for soya bean protein concentrate and soya bean meal than for pea protein concentrate used with fullfat soya bean being intermediate. The replacement of soya bean meal by pea protein or soya protein concentrate in broiler diets to improve protein and amino acid digestibility, might not be justified always.