Effect of added calcium carbonate without and with benzoic acid on weanling pig growth performance, fecal dry matter, and blood Ca and P concentrations

Lowering the calcium carbonate levels in weanling pig diets improved daily gain and gain-to-feed. Also, dietary addition of benzoic acid increased average daily gain and feed intake. Lay Summary The focus of this research was to determine the impacts of lowering the acid binding capacity (ABC-4) of the diet. The ABC-4 is the amount of acid required to lower the pH of a feed ingredient. Therefore, we investigated low calcium carbonate (CaCO3) additions and the interaction between CaCO3 and benzoic acid when provided in the diets of nursery pigs immediately after weaning. Two experiments were conducted where the first experiment showed that increasing CaCO3 decreased average daily gain (ADG) and gain-to-feed (G:F). In the second experiment, there were no interactions between CaCO3 level and benzoic acid inclusion. However, increasing CaCO3 decreased gain-to-feed, and benzoic acid inclusion increased ADG and feed intake. The objective of these studies was to determine the effects of increasing levels of calcium carbonate (CaCO3) with and without benzoic acid on weanling pig growth performance, fecal dry matter (DM), and blood Ca and P concentrations. In experiment 1, 695 pigs (DNA Line 200 x 400, initially 5.9 & PLUSMN; 0.02 kg) were used in a 28 d study. Pigs were weaned at approximately 21 d of age and randomly assigned to pens and then pens were allotted to one of five dietary treatments. Treatment diets were fed from weaning (day 0) to day 14, with a common diet fed from days 14 to 28. Dietary treatments were formulated to provide 0%, 0.45%, 0.90%, 1.35%, and 1.80% added CaCO3 at the expense of ground corn. From days 0 to 14 (treatment period), average daily gain (ADG) and G:F decreased (linear, P & LE; 0.01) as CaCO3 increased. From days 14 to 28 (common period) and for the overall experiment (days 0 to 28), there was no evidence of differences in growth performance between treatments. For fecal DM, there was a trend (quadratic, P = 0.091) where pigs fed with the highest CaCO3 diets had the greatest fecal DM. Experiment 2 used 360 pigs (DNA Line 200 x 400, initially 6.2 & PLUSMN; 0.03 kg) in a 38 d study. Upon arrival to the nursery facility, pigs were randomly assigned to pens and then pens were allotted to one of six dietary treatments. Dietary treatments were fed in three phases with treatment diets fed from days 0 to 10 and days 10 to 24, and a common phase 3 diet fed from days 24 to 38. Dietary treatments were formulated to provide 0.45%, 0.90%, and 1.35% added CaCO3 with or without 0.5% benzoic acid (VevoVitall, DSM Nutritional Products, Parsippany, NJ) added at the expense of ground corn. There was no evidence (P > 0.05) for any CaCO3 by benzoic acid interactions. For the experimental period (days 0 to 24), there was a tendency for benzoic acid to increase ADG (P = 0.056), average daily feed intake (ADFI; P = 0.071), and gain-to-feed ratio (G:F; linear, P = 0.014) as CaCO3 decreased. During the common period (days 24 to 38), pigs previously fed benzoic acid had increased (P = 0.045) ADG and marginally increased (P = 0.091) ADFI. For the overall study, pigs fed benzoic acid had increased ADG (P = 0.011) and ADFI (P = 0.030), marginally increased G:F (P = 0.096) and final body weight (P = 0.059). Serum Ca decreased (linear, P < 0.001) as CaCO3 decreased in the diet. These data show that decreasing the CaCO3 content in the nursery diet immediately after weaning may improve ADG and G:F. Dietary addition of benzoic acid may also provide beneficial effects on ADG and ADFI, regardless of dietary Ca level.