57 Effect of Calcium Carbonate Level with or without Benzoic Acid on Weanling Pig Growth Performance, Fecal Dry Matter, and Blood Ca and P Concentrations

A total of 360 barrows (DNA Line 200×400; initially 6.2 ± 0.03 kg) were used in a 38-d study to evaluate the interactive effects of added dietary calcium carbonate and benzoic acid on nursery pig growth performance, fecal dry matter, and blood Ca and P concentration. Upon arrival to the nursery research facility, pigs were randomly assigned to pens (5 pigs/pen) and pens were allotted to 1 of 6 dietary treatments (12 pens/treatment). Dietary treatments fed from d 0 to 24 were formulated to provide 0.45, 0.90, or 1.35% calcium carbonate with or without 0.5% benzoic acid (VevoVitall, DSM Nutritional Products, Parsippany, NJ). Diets were fed in 3 phases with total Ca of 0.66, 0.83, or 1.00% Ca from d 0 to 10, and 0.54, 0.72, or 0.89% from d 10 to 24. A common diet was fed from d 24 to 38 (0.68% Ca). Serum Ca and P was analyzed on d 21. There were no calcium carbonate×benzoic acid interactions observed for any response criteria (P > 0.10). For the experimental period (d 0 to 24), there was a tendency for benzoic acid to improve ADG (P = 0.056) and ADFI (P = 0.071) with no influence on G:F (P>0.10). Increasing calcium carbonate linearly reduced (P < 0.05) G:F. For serum analysis, serum Ca increased (linear, P < 0.001) as the level of dietary calcium carbonate increased. There were no differences (P > 0.010) in fecal DM. For the overall study (d 0 to 38), pigs fed benzoic acid had increased ADG (P = 0.011) and ADFI (P = 0.030) and marginally improved (P = 0.096) G:F. Calcium carbonate level did not influence overall performance. This data suggests that lower levels of calcium carbonate may improve feed efficiency in early nursey period. Adding benzoic acid to the diet for nursery pigs increased ADG and ADFI, and tended to increase G:F regardless of the calcium carbonate level.