THE EVALUATION AND ENHANCEMENT OF THE NUTRITIVE-VALUE OF YELLOW-SEEDED, GREEN-SEEDED AND BROWN-SEEDED PEA CULTIVARS FOR UNPELLETED DIETS GIVEN TO BROILER-CHICKENS

The evaluation and possible enhancement of the feeding value for broil er chickens of yellow-, green- and brown-seeded pea cultivars were stu died in three experiments. In the first experiment, bioavailable energ y (AME(n)), apparent protein digestibility (APD) and starch digestibil ity were determined. Dietary AME(n), APD and starch digestibility valu es were decreased (P less than or equal to 0.05) with 500 g kg(-1) inc lusion of peas, The AME(n) and starch digestibility were similar (P gr eater than or equal to 0.05) in yellow- and green-seeded cultivars but lower (P less than or equal to 0.05) in the brown-seeded cultivar. Si gnificant differences (P less than or equal to 0.05) were found betwee n the cultivars in APD. The effects of feeding 0, 100, 200 and 400 g k g(-1) of these cultivars on the performance of broiler chicks were exa mined in the second experiment. Concurrently the possibility of allevi ating the detrimental effects of antinutritional factors in peas by pr oviding excess (115% of National Research Council (NRC) requirements) crude protein (CP) and essential amino acids (EAAs) to 400 g kg(-1) pe a-based diets was evaluated. The inclusion of up to 200 g kg(-1) of pe as did not affect weight gains but feed conversion ratio (FCR) was red uced (P less than or equal to 0.05) only for the diet containing the b rown-seeded peas. When peas comprised 400 g kg(-1) of a diet fed to br oiler chicks, weight gains and FCR were depressed (P less than or equa l to 0.05). However, this depression was alleviated by supplying exces s CP and EAAs to these diets. Feed consumption was not affected by die tary inclusion of peas. The influence of adding pectinase only or in c ombination with protease to diets in which peas constituted a major di etary protein source was investigated in experiment 3. Supplementation of diets containing 800 g kg(-1) peas with pectinase alone increased (P less than or equal to 0.05) weight gains by 7.3 percentage units, a bove non-supplemented diets. Feed consumption was also improved (P les s than or equal to 0.05) by the same magnitude. However, feed conversi on was not affected. There was no further response observed by adding protease to these diets. It is concluded that broiler chicks can toler ate up to 200 g kg(-1) peas in their diets, with satisfactory performa nce at 400 g kg(-1) provided CP and EAAs are supplied at 15% in excess of NRC requirements and addition of pectinase to pea-based diets impr oved weight gains and feed consumption.