The aim of this study was to evaluate the effects of a fibrolytic enzyme cocktail applied during ensiling, either alone or in combination with lactic acid bacteria (LAB), on the fermentation characteristics, nutritive value, and microbial community of rice straw silage. Fresh rice straw was assigned to one of three treatments: none (control), a fibrolytic enzyme cocktail (CE, mainly xylanases and cellulase), or commercial cellulase enzyme (CM). Each treatment was applied either alone or in combination with Lactiplantibacillus paraplantarum (LPL). The use of enzymes did not affect (p > 0.05) lactic or acetic acid concentrations after 60 days of ensiling compared with the control silage. However, silage treated with enzyme and LPL exhibited lower acid detergent fiber (ADF) concentrations than the control. However, no differences (p > 0.05) in NDF or ADF degradability was observed between enzyme-treated and control silages. Silage treated with CE exhibited higher relative abundances of Proteobacteria and lower abundances of Firmicutes than the control. Silages inoculated with LPL showed greater Lactobacillus abundance (p < 0.001), while those treated with enzymes in combination with LPL had lower Lactococcus abundance than the control. The addition of the fibrolytic enzyme cocktail improved fermentation quality, as indicated by increased water-soluble carbohydrate content and reduced NH3-N concentration and ADF content; however, it did not enhance fiber digestibility. In contrast, LPL alone improved fermentative quality, nutritive value, and nutrient digestibility of rice straw silage. The combination of the fibrolytic enzyme cocktail and LPL did not accelerate the fermentation process or improve nutrient digestibility of rice straw silage.
Bureenok et al. (Wed,) studied this question.