Influence of Supplementary Cellulolytic Enzymes (Driselase) on the Performance of Broilers Fed Rations Containing Rapeseed Meal

Two experiments were conducted to study the effects of supplementing broiler rations with a multiple cellulolytic enzymes system (Driselase) on the performance of chicks raised to 4 wk of age (exp. 1) and to 8 wk of age (exp. 2). Four broiler rations unsupplemented or supplemented with 0.03% Driselase were used in the study. One of the rations was based on soybean meal and wheat while the other three contained 20% rapeseed meal (produced from Regent, Candle and Turret cultivars of rapeseed) as a partial replacement for soybean meal. The results obtained in both experiments indicated a lack of response in body weight and feed conversion of the chicks to Driselase supplementation. In both experiments, the chicks receiving the rations containing rapeseed meal showed varying degrees of thyroid enlargement depending on the cultivar of rapeseed from which the meal was produced, with Turret meal causing the greatest increase in thyroid size.