Effect of sodium bicarbonate supplementation on ruminal fluid pH, feed intake, nutrient utilization and growth of lambs fed high concentrate diets

This experiment studied effects of increasing levels of dietary sodium bicarbonate (NaHCO3) on ruminal fluid pH, feed intake, nutrient utilization, body weight (BW) gain and feed conversion efficiency of lambs fed high concentrate diets offered ad libitum. Forty weaner (90 days) Malpura lambs, divided into four equal groups, were fed levels of NaHCO3: 0 (control), 7.5, 15.0, or 22.5 g NaHCO3 per of kg feed DM. The feeding experiment was for 91 days. Pala (Zizyphus nummularia) leaves were used as the forage and the diet contained about 25% high glucosinolate mustard meal. Increasing supplementation of NaHCO3 increased ruminal fluid pH linearly (P<0.05), in the range of 6.03–6.44 and linearly (P<0.06) increased trend to NDF and ADF digestibilities. Digestibility of dry matter, organic matter and gross energy did not differ among the treatments. Average daily gain showed linear and quadratic increases with increasing NaHCO3 and were highest in lambs supplemented with 15 g NaHCO3. No differences in daily intake of metabolizable protein occurred, whereas, digestible and metabolizable energy intake per unit live weight gain was higher in NaHCO3 supplemented lambs. For all treatments, lambs were in positive N balance and NaHCO3 supplementation did not alter N retention, calcium and phosphorus utilization, and blood parameters. Incorporation of NaHCO3 to a high concentrate diet fed to weaner lambs improved growth by 35% at 15.0 g NaHCO3 by improving feed intake and fiber digestibility.