This study was conducted to evaluate the effect of supplementing the diet of ewes or rams with sodium bicarbonate (NaHCO3) as buffers at two levels on feed intake, milk yield, milk composition, nutrient digestibility, rumen fermentation and some blood metabolites. Twenty seven healthy mature local ewes were randomly assigned into three similar groups (9 ewes each). Three digestibility trials were also carried out using
twelve local rams randomly assigned into three groups (4 rams/ trial). Each trial lasted for three weeks, the first two weeks were considered as a preliminary period followed by one week collection period . Groups of 9 ewes and 4 rams were the control group fed the basal diet without NaHCO3supplement and treated groups were fed either 1.5 (T1) or 3% (T2) sodium bicarbonate mixed with the concentrate mixture. All animals were fed 70% of their requirements as concentrate mixture while, wheat straw was given ad libitum as roughage. Dietary supplementation of NaHCO3 (1.5 or 3%) increased (P<0.05) dry matter intake (DMI) of roughage and total dry matter intake. Sodium bicarbonate supplement increased (P<0.05) milk yield. The milk fat (%) was improved (P<0.05) in ewes supplemented 3% of NaHCO3 compared to other groups. Dietary supplement of sodium bicarbonate either 1.5 or 3% increased (P<0.05) serum pH and cholesterol. The organic matter, crude protein and crude fiber digestibility coefficients were improved (P<0.05) for rams supplemented with 1.5 and 3%
sodium bicarbonate compared with the control group. Supplementation of sodium bicarbonate to rams rations increased (P<0.05) ruminal pH, concentrations of total VFAs and total protozoa count as compared with the control diet. However, rumen ammonia nitrogen was not affected. In conclusion, dietary sodium bicarbonate in
particular 3% of concentrate mixture improves dry matter intake, milk yield, milk fat (%), nutrients digestibility and fermentation patterns in sheep.