PSIII-12 Evaluation of dietary acidifiers in low acid-binding capacity-4 diets on nursery pig performance and fecal dry matter

A total of 300 pigs (initially 6.1 kg) were used to evaluate dietary acidifiers in low acid-binding capacity-4 (ABC-4) diets on nursery pig performance and fecal dry matter (DM). At weaning, pigs were randomly allotted to 1 of 6 dietary treatments. There were 5 pigs per pen and 10 replications per treatment. Pigs were fed experimental diets in two phases with phase 1 fed from d 0 to 10 post-weaning followed by phase 2 from d 10 to 24. Four diets were formulated to an ABC-4 level of 200 and 250 meq/kg in phase 1 and 2, respectively, by utilizing 4 different dietary acidifiers. Dietary acidifiers included 0.36% fumaric acid (Primary Products Ingredients Americas LLC, Decatur, IL), 0.87% Activate DA (Novus, St. Charles, MO), 1.01% KEM-GEST (Kemin, Des Moines, IA), and 0.85% ACID-AID (Alltech, Nicholasville, KY). Diet 5 did not include any dietary acidifiers which increased the ABC-4 level by 40 meq/kg in both phases. All diets contained 110 mg/kg of Zn provided by the trace mineral premix. Diet 6 was the same formulation as diet 5, but with the addition of 3,000 and 2,000 mg/kg of Zn from ZnO in phase 1 and 2, respectively. The addition of ZnO further increased the ABC-4 level of the diet by 87 and 54 meq/kg in phase 1 and 2, respectively. Following phase 2 experimental diets, all pigs were fed a common corn-soybean meal-based diet until study completion on d 38 post-weaning. There were no differences (P > 0.05) observed between pigs fed the four dietary acidifiers for the duration of the study. In phase 2 (d 10 to 24), the experimental period (d 0 to 24), and overall (d 0 to 38), pigs fed the low ABC-4 diets containing acidifiers had improved (P ≤ 0.020) G:F compared to pigs fed the 40 meq/kg higher ABC-4 diet (without acidifiers). In the experimental period (d 0 to 24), pigs fed the diet containing ZnO tended to have improved (P = 0.052) G:F compared to pigs not fed ZnO. In conclusion, using dietary acidifiers to achieve a low ABC-4 level improved feed efficiency, but there were no differences found between the acidifier sources used in this study. Most dietary acidifiers were included above their supplier-recommended inclusion rates to achieve the targeted low ABC–4 level and only decreased the ABC-4 by 40 meq/kg. Therefore, other aspects of low ABC-4 diet formulation such as low ABC-4 specialty protein sources, lactose sources, low Ca levels, a combination of acidifiers, or other methods must be considered when formulating to target low dietary ABC-4 levels.