Ruminal degradation and in vivo digestibility of processed rapeseed meal

Abstract

The digestibility and nutritive value of rapeseed meal processed in different ways were studied with adult rams fed on alkali-treated straw. The rumen degradability was determined by the nylon bag technique. The rapeseed meal feeds were: 1) untreated rapeseed meal, 2) heat-treated rapeseed meal (2—5 sec. at over 100°C), 3) heat-treated rapeseed meal + 5 % urea phosphate and 4) heat-treated rapeseed meal + 10 % rapeseed hulls. The heat treatment reduced the rumen degradation and in vivo digestibility of the rapeseed meal, although not significantly (P > 0.05). Addition of urea phosphate to the heat-treated rapeseed meal increased the ruminal degradability of the crude protein and improved the digestibility of all the constituents of the rapeseed meal, especially that of crude fibre (P > 0.05). The rapeseed hulls had no noticeable effect on digestibility.