Sunnhemp (Crotalaria juncea, L.) silage can enrich rumen fermentation process, microbial protein synthesis, and nitrogen utilization efficiency in beef cattle crossbreds.

The objective of this experiment was to evaluate the effect of leguminous fodder silage on rumen fermentation, nutrient digestibility, and utilization in beef cattle crossbreds. Four cattle, with an average live weight of 280 ± 10 kg, were used in a 4 × 4 Latin square design with supplementation of various levels of sunnhemp silage (SHS). Sunnhemp silage was fed to cattle at 0, 1, 1.5, and 2 kg DM SHS/head/day. The DM, OM, and CP digestibilities were increased (P < 0.05), and the highest value was found by feeding 2 kg DM SHS/head/day. Total volatile fatty acids and individual volatile fatty acid (VFA) especially C3 were increased (P < 0.01), while C2 and C2:C3 ratios were decreased (P < 0.01) when SHS was supplemented. Nitrogen utilization efficiency and urinary purine derivatives were increased (P < 0.01) by the SHS supplementation. In conclusion, these data suggest that feeding SHS at 1.5 to 2 kg DM/ head/day can significantly increase rumen fermentation end-products, nitrogen utilization efficiency, and microbial protein synthesis. Sunnhemp silage can be practically processed and provided as a good roughage source for ruminants. Therefore, sunnhemp silage is recommended as a feeding intervention in the sub-tropical and tropical regions to support the sustainable livestock production.