Feeding value of guar meal for poultry

Guar meal (Cyamopsis tetragonoloba), a byproduct of guar gum industry is plentifully available (3.2 million quintals per annum) in northwestern parts of the country. Guar meal left after removal of gum i.e. the endosperm from both hull and germ of guar seed is potential alternative protein feed. Chemical composition of roasted guar meal was reported 50.27% protein, 5.32% ether extract, 6.24% crude fibre, 7.08% total ash, 1.28% acid insoluble ash, 31.09% NFE, 0.13% calcium and 0.30% phosphorus on dry matter basis. The pepsin digestibility in toasted guar meal was reported 84.82%. The crude protein contents of germ, hull and endosperm (gum) are 45, 35, 5–6% and they contribute 44, 21, 29–35% of the guar bean respectively. These fractions contain residual gum in different concentrations. Guar meal contains various anti nutritional factors which include gum 6–18%, saponins 9–14%, hydrocyanic acid 5–20 mg/100 gm and variable proportion of trypsin inhibitor, haemagglutinin and tannins. Despite of these deleterious effects GM is cheaper and a good source of essential amino acids. Guar gum is a highly viscous galactomannan polysaccharide. The residual guar gum is sticky in nature and reduces the nitrogen retention, energy utilization and fat absorption and thus depresses the growth and increases mortality in poultry. Toasting of guar meal reported to neutilize anti nutritional factors like trypsin inhibitor and urease activity. Enzyme supplementation (β-mannanase) and solid state fermentation are emerging techniques reported to reduce intestinal viscosity and counteracted deleterious effects associated with increased viscosity of the intestinal contents due to residual gum. Guar meal supplementation in diet is not only economical but also improved immune competence, gut health and significantly reduced serum cholesterol and glucose level. It is suggested that raw guar meal, toasted guar meal, fungal fermented guar meal and toasted guar meal with enzyme supplementation (beta mannanase or enzyme combination) can be supplemented in broiler and layer rations 2.5, 5.0, 7.5 and 10% inclusion level respectively as high protein feed without any adverse effect.