The objective was to test the hypothesis that a novel acidifier [i.e., Protacid Soy Plus (PSP)] improves growth performance of weanling pigs. A total of 128 newly weaned pigs [initial body weight (BW): 5.60 ± 0.27 kg] were allotted to 32 pens with four pigs per pen and eight replicate pens per treatment. Four diets were formulated for phases 1 and 2. The control diet contained corn, soybean meal (SBM), animal proteins, enzyme-treated SBM, and 4,000 mg/kg zinc oxide. A negative control (NC) diet did not contain zinc oxide. Two additional diets were formulated by adding 3% PSP (i.e., PSP diet) or 1% PSP and 4,000 mg/kg zinc oxide (i.e., PSP+Zn diet) to the NC diet. Less enzyme-treated SBM was used in the two diets with PSP. A common diet containing no PSP or zinc oxide was fed to pigs during phase 3. Average daily gain (ADG), average daily feed intake (ADFI), and gain to feed (G:F) were calculated at the end of each phase. At the conclusion of phases 1 and 2, fecal scores were recorded, and fecal dry matter and nitrogen were analyzed. Data were analyzed using the PROC MIXED of SAS. The model included diet as fixed variable and replicate as random variable. Results indicated that ADG and ADFI during phase 1 were not affected by diet, but G:F was greater (P < 0.05) for pigs fed the PSP diet compared with pigs fed the NC diet (Table 1). In phase 2, final BW of pigs fed the control diet or the PSP+Zn diet tended to be greater (P < 0.10) than for pigs fed the NC or PSP diets. Pigs fed the control diet had greater (P < 0.05) ADFI compared with pigs fed the NC or PSP diets, but ADFI was not different between the control and PSP+Zn diets. In phase 3, ADG and ADFI were greater (P < 0.05) for pigs previously fed the PSP diet compared with pigs previously fed the PSP+Zn diet. On day 14, fecal score was reduced (P < 0.05) in pigs fed the PSP+Zn diet compared with pigs fed the NC diet (Table 2). Nitrogen in feces tended to be reduced (P < 0.10) when pigs were fed the PSP+Zn diet compared with pigs fed the NC diet. In conclusion, supplementation of PSP improved G:F of weanling pigs during phase 1. The combination of PSP and zinc oxide reduced fecal score and nitrogen in feces without compromising growth performance of pigs compared with diets containing zinc oxide only. The improved performance of pigs may be a result of the PSP, which may reduce the pH in the stomach, which may improve protein digestion and nutrient utilization in the body.

Lee, S., J. Ibagon and H. Stein. 2026. Growth Performance of Weanling Pigs Fed Diets Supplemented with a Novel Acidifier. ASAS Midwest Section Meeting. Abstract PS2-13. https://doi.org/10.1093/jas/skag107.326