Fractionation of sunflower oilcake meal and use of the low-fibre fraction together with full-fat soy-bean meal as a replacement for fish-meal in broiler diets.
Nutrient concentrations of various fractions of sunflower oilcake meal were studied by sieving the meal through successive screens to obtain particles of > 850 µ, 850 µ < > 425 µ, 425 µ < > 250 µ, 250 µ < > 180 µ and < 180 µ in diameter. In a further study sunflower oilcake meal, containing only particles with a diameter of > 180 µ, was combined with full-fat soy-bean meal treated in a microwave oven (vegetable protein broiler diet) and compared to a broiler diet containing only fish-meal as a protein source. Crude-protein concentration increased from 31,2% to 46,0% as particle size decreased from 850 µ to 180 µ. Amino acid concentration increased in a similar fashion, in contrast to the crude-fibre content which decreased from 26,8% to 7,8% over the same range. The growth rate of broilers fed any of the vegetable diets was slightly less than that of broilers fed any of the fish-meal diets. This may chiefly be ascribed to a depression in intake, although the efficiency of feed utilization was not affected. Partial replacement of fishmeal by vegetable proteins did not cause any reduction in broiler performance. It was therefore concluded that a policy of partial replacement is to be preferred to one of total replacement.