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1. The effects of a mixture of pure enzymes (cellulase, hemicellulase and pectinase) and a commercial enzyme, Energex, were examined on performance and metabolisabilities in broiler chicks given a maize-soybean meal diet. Composition of the mixed enzyme was similar to Energex except that protease was not present. 2. Chicks were divided into three groups: control, mixed enzyme and Energex with 7 replicates per group. Male broiler chicks were raised at 25 degrees C in wire-floored cages for 12 d from 15 d of age. Feed and water were offered ad libitum. 3. The Energex group gained significantly more weight and the mixed enzyme group tended to gain more than the control. Feed intakes were similar and thus the feed conversion ratio of Energex was significantly improved while it tended to be improved by the mixed enzyme. 4. The mixed enzyme group showed significant improvement in carcase and muscle weight when compared with the control group. The mixed enzyme group also showed significant improvement in organic matter and crude protein metabolisabilities. In the groups given enzyme, abdominal fat weight tended to decrease. 5. It is concluded that a combination of cellulase, hemicellulase and pectinase is effective in improving organic matter and crude protein metabolisabilities and carcase yield of broilers on a maize-soybean meal diet.

1. The apparent ileal nitrogen (N) and amino acid digestibilities in chaya leaf meal (CLM) (Cnidoscolus aconitifolius) with added enzymes, and the same variables in diets containing different amounts of CLM were studied in chickens. 2. In the first experiment pectinase, beta-glucanase, and pectinase + beta-glucanase were added to CLM. In the second experiment, there were three diets based on maize and soybean: 0, 150 and 250 g/kg CLM. 3. Pectinase significantly increased both lysine and overall amino acid digestibilities in CLM. 4. In experiment 2, the amino acid digestibility in birds fed on CLM250 was lower than that from birds fed on either control or CLM150. Only the digestibilities of alanine, arginine and proline were lower in birds fed on CLM150 than in those fed on the control diet. Nitrogen digestibility was lower in birds fed on the CLM250 diet than on either control or CLM150 diets. These findings were attributed to the increasing concentration of fibre with increasing dietary CLM.

1. The effects of two enzyme products on the nutritive value of soyabean meal (SBM) were investigated with the emphasis on changes in composition of non-starch polysaccharides (NSP) along the digestive tract. Enzyme A was a commercially available product containing mainly hemicellulase, pectinase, beta-glucanase and some protease activities and Enzyme B was an experimental product with mainly beta-galactanase activity. 2. Enzymes were added at the recommended dosage (normal) and at 5 times the recommended dosage (high) to a semi-purified diet based on maize with SBM as the sole protein source. 3. The enzymes had no effect on digesta viscosity in the jejunum or ileum. 4. Enzyme A at the high dosage significantly (P<0.05) improved AMEN, reduced excreta moisture content and improved ileal protein digestibility. The addition of the same enzyme at the recommended dosage had no effect on any of the above parameters. 5. Analysis of the monosaccharide composition revealed that Enzyme A tended to reduce the amounts of rhamnose and galactose in the soluble and insoluble NSP fractions in thejejunal and ileal digesta. The reduction was significant (P<0.05) when the same enzyme was added at the high dosage. 6. Enzyme B significantly (P<0.05) improved AMEN of the diet but not the growth or the feed conversion ratio (FCR) of the birds. Enzyme B at the high dosage significantly reduced (P<0.05) ileal protein digestibility. 7. Enzyme B significantly (P<0.05) increased the amount of free sugars in thejejunum and reduced (P<0.05) the concentration of soluble NSP in the ileum. 8. Analysis of the monosaccharide composition in the jejunal and ileal digesta showed that this enzyme was highly effective in releasing galactose from both the soluble and insoluble NSP fractions. 9. It is concluded that glycanases with galactanase and pectinase activities supplemented at appropriate dosages can improve the digestibility of the NSP in SBM and increase the metabolisable energy content of the diet containing high levels of SBM. 10. Furthermore, the addition of Enzyme B at the high dosage significantly (P<0.05) reduced protein digestibility without any measurable reduction in growth performance.