Altering dietary rumen degradable protein concentration: Impact on nutrient intake, ruminal characteristics and nitrogen balance in Nili-Ravi buffalo bulls fed ad libitum

Four ruminally cannulated Nil-Raw buffalo bulls were used in a 4 x 4 Latin Square Design to determine the influence of varying level of ruminally degradable protein (RDP) on dry matter Intake (DMI), ruminal characteristics, digestibility, blood pH, blood urea nitrogen (BUN) and nitrogen (N) balance Four isonitrogenous and isocaloric diets were formulated The C diet contained 50 % RDP while medium, high and very high RDP diets had 66, 82 and 100 % RDP of the total crude protein (CP) and were denoted as MRDP, HRDP and VHRDP, respectively The bulls were fed ad libitum Nutrients intake decreased linearly with increasing the RDP proportion of total dietary CP A quadratic effect of RDP on ruminal pH was noticed with increasing level of RDP with quadratic maxima at 66 % RDP diet Increasing level of dietary RDP also had a quadratic effect on total bacterial and protozoal count with maximum microbial count at 82 % RDP diet Increasing dietary RDP resulted in linear increase in DM digestibility However, NDF digestibility was decreased linearly with increasing the level of dietary RDP A linear increase in ruminal NH3-N and BUN was noticed due to increasing level of dietary RDP Higher positive N balance was notices in bulls fed C diet compared to those fed MRDP, HRDP and VHRDP diets The findings of this study indicated that buffalo bulls can effectively utilize 13 12% RDP of DM without any adverse effect on rumen and blood parameters