Utilization of palm kernel meal and copra meal by poultry

Palm kernel meal (PKM) and copra meal (CM) are derived from the nuts of palm trees and are available in large quantities in many tropical countries. These potential feedstuffs are not widely used either for animal production or other purposes. Due to their high fibre contents, imbalanced amino acids, Maillard products (due to heat damage during drying and oil extraction processes) and their susceptibility to mould attack, these by-products have been regarded as low quality feedstuffs. However, if their value could be improved so that their inclusion in animal feeds resulted in good production, there would be a large number of benefits. A total of ten experiments have been conducted to improve the quality of these ingredients in broiler diets. There are two main scenarios for improving their use as feedstuffs, namely, by addition of exogenous enzymes and nutrients which are deficient and by manipulation of the physical characteristics of the ingredients. This project investigated the physical characteristics (bulk density and water holding capacity) and feeding value of PKM and CM by feeding the pure PKM and CM plus additional vitamins and minerals in poultry diets. Improvement of the quality of PKM was mainly based on nutritional manipulation by considering the digestible amino acids of the diet and adding enzymes. To increase the feeding value of copra meal, physical treatments were proposed, along with using exogenous enzymes and formulating diets based on digestible amino acid. The physical treatments applied in this study were pelleting, crumbling, soaking and finely grinding the diets. Parameters measured were growth rate, feed intake, feed conversion ratio, feed digestibility, apparent metabolizable energy (AME) of the diet, passage rate, jejunal viscosity, gut dimensions and digesta weight. The results of the experiments using palm kernel meal showed that bulk density and water holding capacity were 0.57 g/cm3 and 2.93 g water/g feed respectively. These values are close to the values of conventional feedstuffs tested in this study. Accordingly, PKM is neither bulky nor watery when soaked. Therefore, feed intake was not affected by PKM. Palm kernel meal contains 13.6 % protein with high arginine content, being 19.2 mg/g. Ileal digestibilities of crude protein, arginine, lysine and methionine in PKM were 53.6, 81.9, 57.2 and 71.5% respectively. Palm kernel meal could be used up to 40%, provided that energy and amino acids are balanced. Body weights of birds fed diets containing up to 40% PKM in the diet were similar to the body weight of birds fed corn-soy diets. Feed digestibility was low in PKM based diets, due to the high dietary fibre, causing birds to consume large amounts of feed to gain optimal growth. Jejunal digesta viscosity of birds fed PKM based diets was low compared with those of birds fed a corn soy diet. The use of enzymes did not improve the birds production significantly. However, feed digestibility and AME of the diet were increased when enzymes were added to the diet. Analysis of CM indicated that is bulk density and water holding capacity were much less and much greater respectively than values for conventional feedstuffs, being about 0.49 g/cm3 for bulk density and 4.14 g water/g feed for water holding capacity. Copra meal contains 21.7% crude protein with high arginine content (30.5 mg/g) but low in lysine (5.5 mg/g). Ileal digestibility of crude protein, arginine, lysine and methionine were 63.1, 85.6, 51.3 and 71.1% respectively. The use of CM in the diet lowered feed digestibility and AME of the diet. The birds fed CM based diets consumed more water and less feed than did birds fed corn-soy (CS) diets. The use of enzymes did not improve the growth rate of birds in the starter period but they did increase it to a similar level compared to birds fed the CS diet when the birds were kept for six or more weeks. Soaking the diet gave similar results to the addition of enzymes. However, fine grinding either CM or the whole diet decreased the performance of birds. Significant improvement in the growth rate of birds was made when either CM or the diet was pelleted and fed as crumbles but not when the pelleted material was finely ground. Measurement of gut response of birds consuming CM showed that gizzard weight was increased when the birds were fed the unmodified CM or pelleted CM but not when fed fine ground, soaked or enzyme supplemented CM diets. However, the birds fed the CM based diet had heavier intestines than those of birds fed the CS diet. No doubt due to their larger body size, the beak size was bigger in birds fed larger feed particle sizes. There was a significant correlation between the size of the feed particles eaten by the birds and the width of the beak. The birds tended to prefer a feed particles size of 40% of the width of the beak. Larger feed particle sizes travelled down the digestive tract faster than finer feed particle sizes thus increasing feed intake and hence growth rate. In conclusion, there was no deleterious effect in using up to 40 % PKM in the diet provided that the diet was balanced, particularly in digestible amino acids and energy. Enzyme supplementation increased the digestibility of PKM based diets. Even if CM based diets were balanced, the use of enzymes, soaking the diets or pelleting the CM diet was needed to improve the feeding value of CM