This trial was conducted to check the effect of commercially available hydrolysable tannin (Silvafeed Bypro) on feed intake, protein digestibility, rumen pH, ammonia nitrogen and blood urea nitrogen in Nili Ravi buffalo bulls. Four cannulated buffalo bulls were alloted in 4*4 Latin Square Design. The diet consisted of 50% seasonal fodder and 50 percent concentrate. Four iso-caloric (ME: 2800 kcal/kg) and iso-nitrogenous (CP: 18 percent) concentrate rations T1, T2, T3 and T4 were formulated and supplemented with 0, 10, 20 and 30 g hydrolysable tannin respectively per animal on daily basis. Diets as a total mixed ration were given to the bulls ad libitum twice a day. The results showed that adding tannin in diet had unaltered effect (P GT 0.05) on feed intake, digestibility of crude protein, ruminal pH, ammonia nitrogen and blood urea nitrogen. However, slightly increased numerical values were found for feed intake, crude protein digestibility and ruminal pH while slightly decreased numerical values were found for ruminal ammonia nitrogen and blood urea nitrogen at different inclusion levels of hydrolysable tannin in diet. It is concluded that numerical values for feed intake, crude protein digestibility, ruminal pH, ammonia nitrogen and blood urea nitrogen are slightly better but non-significant than control when buffalo bull were fed diets supplemented with hydrolysable tannin.