Sodium Bentonite or Sodium Bicarbonate as Aids in Feeding High-Concentrate Diets to Lambs

Studies were conducted to compare bentonite and sodium bicarbonate as dietary aids in adaptation and subsequent performance of lambs fed high-concentrate diets under various conditions of protein supplementation. Three protein variations, including no supplemental protein (NSP), soybean meal (SBM) or urea, were factored with a control, 2% or 4% sodium bentonite, and 2% or 4% sodium bicarbonate in a 3 × 5 factorial design. The 15 treatments were replicated three times with 10 lambs per pen (total of 450 lambs). The feeding of 2% bentonite, 4% bentonite or 2% sodium bicarbonate was beneficial to lambs during the initial 21 days of a high-concentrate feeding regime as evidenced by improved (nonsignificant) average daily gain (ADG) and feed per gain during this period. However, there were no differences in overall 98-day ADG of lambs fed these diets vs the controls. The feeding of diets containing 4% bentonite or 4% sodium bicarbonate lowered (P<.05) overall ADG in comparison to controls. ADG of lambs fed no supplemental protein (NSP) was depressed when compared to the performance of those receiving supplemental protein as urea or SBM. No protein × treatment interactions were observed. Both levels of bentonite or sodium bicarbonate lowered (P<.05) blood serum calcium levels. Increases (P<.05) in serum magnesium levels were associated with 4% bentonite and 4% sodium bicarbonate diets. Approximately 19% of the lambs fed sodium bicarbonate diets died as a result of phosphatic urinary calculi or were found to have nonobstructive calculi when slaughtered upon completion of the experiment. Nine lambs died as a result of polioencephalomalacia, seven of which were fed 4% bentonite diets.