The intake of Digitaria pentzii grown with sulphur fertilizer (0,14%; + S) was almost 50% higher than that of unfertilized forage (0,08%; – S). Results showed no differences in plant anatomy or in rumen bacterial populations in sheep fed + S and – S Digitaria. However, the + S Digitaria had a greater fungal population and caused a much lower breaking strength of the leaves when incubated with antibiotics compared to the unfertilized forage (- S). It is postulated that fungal activity in sheep fed + S Digitaria pentzii permitted a more rapid reduction in the size of feed particles in the rumen and hence greater DM digestion and feed intake.