Effect of pelleting and associations with maize or wheat on the nutritive value of smooth pea (Pisum sativum) seeds in adult cockerels.

Four types of diet were tested: 960 g maize/kg (M), 960 g wheat/kg (W), 463 g maize added to 497 g of smooth peas/kg (PM) and 463 g wheat added to 497 g smooth peas/kg (PW). Three treatments were applied to each of these 4 diets: grinding (OP), one steam pelleting (1 P) and two successive steam pelleting (2 P). The pelleted diets were ground before feeding. Adult cockerels received all the diets whereas rats received only W and PW diets. Apparent metabolisable energy values corrected for N-equilibrium (AMEn), protein and starch digestibilities were measured in adult cockerels. Digestible energy (DE) values were measured in rats. The AMEn values of cereals remained practically unchanged by pelleting, whereas that of smooth peas was increased by between 1.8-4.6% after pelleting. Pelleting also induced 3.5 and 5.4% increases respectively in the digestibilities of pea protein and starch. Pelleting did not change the DE values measured in rats. The AMEn values of smooth peas mixed with maize were 4.6% higher than those of smooth peas mixed with wheat. The true digestibility of pea protein was 8.4% higher in the former mixture, whereas the pea starch digestibility remained unchanged. Calculation showed that most of the pea AMEn variations could be explained in terms of variations in protein and starch digestibilities.