The Effects of Enzyme Supplementation on the Nutritive Value of Rye Grain (Secale cereale) for the Young Broiler Chick

Two dose-response experiments utilizing differing enzyme concentrations were carried out to determine the level of a crude enzyme preparation (Trichoderma viride cellulase) required to obtain maximum growth performance in young broiler chicks fed a 60% rye diet. Enzyme concentrations utilized in these studies ranged from .05 to 12.8 g enzyme/kg diet. Enzyme supplementation at the 3.2 g/kg diet level yielded increases in feed consumption and weight gain of 71 and 193%, respectively; and the feed to gain ratio was improved by 43% compared with that for the unsupplemented rye control diet. As no further growth response was obtained by increasing the enzyme concentration, the enzyme level utilized in a subsequent study was 3.2 g/kg diet. A balance study using 2-wk-old broiler chicks was carried out to determine the effect of enzyme supplementation on the bioavailable energy (AMEn) and apparent protein digestibility (APD) of a 60% wheat diet replaced by rye in 10% increments. In the 60% rye diets, the enzyme addition increased the dietary AMEn and APD by 23 and 12%, respectively, compared with the unsupplemented diet. The AMEn and APD of the 60% wheat control diet were increased 9.7 and 4.6%, respectively, by enzyme addition. The data suggest that the AMEn of rye grain is increased by enzyme supplementation; however, alternate methodology will have to be employed to quantitatively determine the extent of these improvements.