“…The high digestibility of fiber fractions in the P1S2 treatment was due to the optimum dose combination of P and S minerals for rumen microbes' growth and activity, especially cellulolytic bacteria in degrading feed. Suyitman et al (2015) stated that the increase in population and cellulolytic microbial activity would increase the digestibility of NDF, ADF and cellulose. Mineral P is an essential mineral to support microbial growth, especially fiber digesting microbes (Soetan et al, 2010).…”