THE EFFECT OF ENZYME SUPPLEMENTATION ON THE APPARENT METABOLIZABLE ENERGY AND NUTRIENT DIGESTIBILITIES OF WHEAT, BARLEY, OATS, AND RYE FOR THE YOUNG BROILER CHICK

The influence of enzyme supplementation on the bioavailable energy (AME(n)) and apparent digestibilities of lipid (ALD) and protein (APD) in young broiler chicks was examined for diets containing either wheat, hulled or hulless barley, naked oats, or spring rye. Dietary AME(n), APD, and ALD values were depressed (P less-than-or-equal-to.01) for all test grains (except hulled Bedford barley) as the inclusion rate of the grain replacing wheat increased. The antinutritives, beta-glucans (barley and oats) and pentosans (rye), had the most pronounced effect on ALD. The decreases in ALD were 43, 77, and 67% for chicks fed diets containing 70% Scout barley (hulless), Terra oats, and Gazelle rye, respectively, compared with those fed the control wheat diet. Enzyme supplementation increased (P less-than-or-equal-to .01) AME(n), APD, and ALD for all test cereals. The corresponding increases in the AME(n), of the enzyme-supplemented diets containing 70% HY320 wheat, Bedford barley, Scout barley, Terra oats, and Gazelle rye diets were 4, 7, 42, 33, and 14%, respectively, compared with their unsupplemented counterparts. Enzyme treatment also improved (P less-than-or-equal-to .01) weight gains and feed conversion efficiencies of chicks fed diets containing each of the cereals. Overall, the results demonstrate that the nutritive value of cereal grains such as wheat, barley, oats, and rye can be improved by the addition of crude fungal extracts to the diet of young chicks.