Rapeseed provides multi-products as human food and animal feed especially the oil and meal. Rapeseed oil and meal after extraction are nutritious and have been used in animal feeding. This study aimed at studying the effect of rapeseed pod meal as the replacement of concentrate (RPM) on in vitro gas and fermentation characteristics. Dietary treatments were imposed in a 2 × 6 factorial arrangement according to a completely randomized design (CRD). The first factor was two ratios of roughage to concentrate (R:C at 60:40, and 40:60) and the second factor was six levels of RPM at 0, 20, 40, 60, 80, and 100% of dietary substrate. The results revealed that the R:C ratio and RPM increased kinetics of gas production, in vitro degradability and improved rumen fermentation (P < 0.001). Ratio of R:C influenced (P < 0.05) on both protozoal population and methane production, while level of RPR did not. Both factors had influenced (P < 0.01) a, a + b, and c, as well as total gas production; nevertheless, there were no interactions (P > 0.05). Interestingly, both factors have greatly impacted on TVFA, C3 (P < 0.01) and tended to reduce methane production as level of RPM replacement increased. In conclusion, RPM improved rumen fermentation and increased in vitro DM degradability, hence is potential for replacement of concentrate and effectively used for ruminant feeding.
Keywords: Alternative feed; Digestibility; Protein.