PSVI-20 Effects of Adding Potassium Bicarbonate to Diets with High or and Low Crystalline Lysine as a Way to Influence DCAD on Finishing Pig Growth Performance

Abstract

Abstract This experiment was conducted to evaluate the effect of balancing dietary cation-anion difference (DCAD), via added potassium bicarbonate (KHCO3), in diets containing low or high levels of L-Lys HCl on growth performance of growing-finishing pigs. A total of 1,944 pigs (PIC L337 × 1050, initially 35.2±0.85 kg) were used in a 120-d study. Pens of pigs were blocked by BW and randomly allotted to 1 of 4 dietary treatments in a randomized complete block design arranged in a 2×2 factorial with main effects of KHCO3 (0 vs 0.4%), and L-Lys HCl level (low vs. high), with 27 pigs/pen and 18 replicates/treatment. Diets were corn-soybean meal-based and formulated in 4 dietary phases (d 0-20, 30-58, 58-86, and 86-120). Diets were formulated in each phase such that the diet containing a low level of L-Lys HCl (0.14-0.21% depending on phase) without KHCO3, had similar calculated DCAD as the diet containing a high level of L-Lys HCl (0.36 to 0.43% depending on phase) with KHCO3. The DCAD for these 2 treatments were approximately 230, 200, 184, and 169 mEq/kg (phase 1, 2, 3, 4, respectively). The diets with low levels of L-Lys HCl with KHCO3 had the greatest DCAD in each phase (approximately 50 mEq/kg above the low L-Lys HCl without KHCO3 diet), while the diet with a high level of L-Lys HCl without KHCO3 had the least DCAD (approximately 50 mEq/kg below the high L-Lys HCl with KHCO3 diet). Overall, there was no evidence (P > 0.10) for a KHCO3 × L-Lys HCl interaction or main effect for any observed growth responses or carcass characteristics. The results of this study suggest that supplementing KHCO3 to finishing pig diets with either high or low levels of L-Lys HCl and the corresponding changes in DCAD values did not impact growth performance or carcass characteristics.