The feeding value for broiler chickens of pea chips derived from milled peas ( Pisum sativum L.) during air classification into starch fractions

Abstract

Two pea products, yellow pea chips (YPC) and green pea chips (GPC) that were derived from milled peas during air classification into pea starch fractions were evaluated for their nutritional value in three experiments. The products were found to contain 298.3 and 281.3 g kg −1 crude protein, 7.28 and 7.10 g lysine per 16 g N and 1.05 and 0.94 g methionine per 16 g N for YPC and GPC, respectively. The apparent metabolisable energy value of YPC was higher ( P ≤ 0.05) than that of GPC, 11.50 vs. 11.28 MJ kg −1, respectively. A similar result was also obtained with starch digestibility, 81.6 vs. 77.4% ( P ≤ 0.05); however, apparent protein digestibility was similar ( P ≥ 0.05) (experiment 1). In experiment 2, YPC or GPC replaced corn and soybean meal at 0, 150, 300 and 450 g kg −1 in broiler chick diets. Weight gain and feed conversion ratio (FCR) were similar ( P > 0.01) for birds fed the 150 g kg −1 of YPC (397.2 g, 1.41) or GPC (390.4 g, 1.42) diet and the control (403.1 g, 1.38) diet. At 300 and 450 g kg −1 inclusion levels, weight gain (YPC, 377.9 and 345.5 g; GPC, 362.9 and 306.6 g) and FCR (YPC, 1.48 and 1.51; GPC, 1.47 and 1.61) decreased significantly ( P < 0.01) for both products relative to the control (403.1 g, 1.38). Feed consumption decreased with increasing levels of pea chips in the diets but the effect was significant ( P < 0.01) only in those diets containing 450 g kg −1. In experiment 3, diets containing 300 g kg − of YPC or GPC were supplemented with two levels of DL-methionine to 100% and 120% of the NRC requirements. The performance of these birds was still lower ( P < 0.01) than that of birds fed the control diet. The fact that these pea by-products at 300 g kg −1 inclusion level with methionine supplementation were unable to sustain broiler performance equal to birds fed a conventional corn-soy diet, suggests that they should not be fed to broiler chicks in excess of 150 g kg −1.