CHARACTERIZATION OF THE NUTRITIONAL INTERACTIONS BETWEEN ORGANIC-ACIDS AND INORGANIC BASES IN THE PIG AND CHICK

Four experiments were conducted to characterize the interactions betwe en fumaric (FA), malic (MA), or citric acid (CA) and NaHCO3. In two ex periments, seven diets were formulated containing 2.5% FA, MA, and CA, with or without 2.3, 1.9, or 1.4% NaHCO3, respectively, as well as a control diet (no addition of organic acids or NaHCO3) for 28-d-old pig s (Exp. 1, corn-soy protein concentrate-based diet) and 1-wk-old chick s (Exp. 4, corn-soy-based diet). In Exp. 1, at 2 and 4 wk, the FA + Na HCO3 treatment resulted in greater average daily gain (ADG) and feed i ntake (ADFI) compared with the control(P < .05). In Exp. 2, 28-d-old p igs were fed corn-soy diets with .9, 1.6, and 2.3% NaHCO3 in addition to 2.5% FA. After wk 2, there was a quadratic response in ADG (P < .08 ) and ADFI (P < .05) when increasing levels of NaHCO3 were added to th e diet. This was true at wk 4 for both ADG; and ADFI (P < .05). In Exp . 3, finishing pigs were fed corn-soy diets containing 2.5% FA or 2.5% FA + 2.3% NaHCO3 added to a control diet. No effect (P < .05) of FA o r NaHCO3 was observed. In Exp. 4, the combination of CA c NaHCO3 or MA + NaHCO3 was superior to FA + NaHCO3 for ADG (P < .08) and ADFI (P < .05) when fed to young chicks.