PSI-6 - Evaluating Formic Acid and Glycerol Monolaurate Alone or in Combination on Weanling Pig Growth and Fecal Consistency

Abstract: A total of 350 weanling pigs (DNA 200 x 400, initially 5.67 0.06 kg BW) were fed for 42 days in a completely randomized design. There were 5 pigs/pen and 14 pens/treatment. The 5 dietary treatments included: 1) nursery diet with no additives (CON), 2) control with 3,000 ppm ZnO in phase 1 and 2,000 ppm ZnO in phase 2 (ZnO); 3) control with 0.7% formic acid (Amasil®NA, BASF; FA), 4) control with 0.18% glycerol monolaurate (Natural Biologics GML, Newfield, NY; GML), 5) control with a 1.0% blend of formic acid and GML (FORMI® 3G, ADDCON GmbH, Bitterfeld-Wolfen, Germany; FORMI). Individual pig and feeder weights were collected weekly to determine average daily gain (ADG), average daily feed intake (ADFI), and gain to feed (G:F). From d 7 to d 35, fresh fecal samples (10 g) were collected weekly from the same 3 pigs per pen. Samples were dried in a 55 oven for 48 h to determine fecal DM %. In the first week post-weaning, pigs fed ZnO or FORMI 3G had increased (P = 0.03) ADG compared to pigs fed the control. From d 0 to d 42, pigs fed GML had reduced (P < 0.0001) ADG compared to pigs fed the control, ZnO, or FORMI 3G. No evidence of differences (P > 0.05) were observed for ADFI and G:F. For fecal DM, there was a significant treatment ´ day interaction (P = 0.04). Pigs fed GML had significantly lower fecal DM % on d 7, but a higher fecal DM % on d 14 and 21. By d 28, fecal DM had standardized across dietary treatments. In summary, feeding FA and GML alone or together did not improve growth performance compared to a control during our experiment.