Improving the nutritional value and rumen fermentation characteristics of sesame seed coats through bioconversion approach using exogenous fibrolytic enzymes produced by Trichoderma longibrachiatum

Sesame seed coat (SSC), agro-industrial waste of Halava, is characterized by high fiber content, moderate energy, low digestibility, and sugar. The aim of this study was to improve their nutritional value and rumen fermentation characteristics through a bioconversion approach using liquid exogenous fibrolytic enzymes (EFE) produced by Trichoderma longibrachiatum. SSC was pre-treated for 12 h with EFE (xylanases, endoglucanase, and exoglucanase) at concentrations of 0, 1, 2, and 4 µl g−1 dry matter (DM). The in vitro gas production technique with cow inoculum was used to determine rumen fermentation. At the end of fermentation, dry matter digestibility (DMD) as well as protozoa, ruminal fibrolytic enzyme activity, ruminal pH, and ammonia–nitrogen (NH3-N) were determined, and net energy-lactation (NEL), total short-chain fatty acids (SCFA), and microbial crude protein synthesis (MCP) were estimated. Our results showed that the highest dose of EFE improved the amount and rate of rumen fermentation (p < 0.05) and decreased lag time in onset of fermentation (p < 0.05). In addition, it increased (p < 0.05) DMD, NEL, SCFA, and MCP, while NH3-N decreased (p < 0.05) and ruminal pH was unaffected (p > 0.05). This result was due to hydrolysis (p < 0.05) of fiber content and release (p < 0.05) of total and reducing sugars, as well as the increase (p < 0.05) of ruminal fibrolytic enzyme activity and protozoa. The low and medium had no effect on the nutritional value of SSC. This eco-friendly bioprocess with the high dose of EFE can be a good strategy for bioconversion of these agro-industrial wastes into high-energy feeds. Graphical abstract: [Figure not available: see fulltext.]