Effects of Lactobacillus acidophilus fermentation product supplementation in different nutrient density diets on growth performance, nutrient digestibility, fecal microbiota and fecal noxious gas emissions in weanling pigs

Abstract Text: Energy density may influence the efficacy of probiotics in pigs. This study aims to determine the effects of LAFP (Lactobacillus acidophilus fermentation product; SynGenX^®, Diamond V, Cedar Rapids, IA) in different energy diets on growth performance, nutrient digestibility, fecal microbiota and noxious gas emission in weaning pigs. A total of 140 weaning pigs (28d) were used in a 6-week trial, which allotted into 4 dietary treatments with two levels of LAFP supplementation (0 or 1g/kg) and two levels of energy (Phase 1: d 1 to 14, 3750 or 3900kcal/kg; Phase 2: d 15 to 42, 3550 or 3700kcal/kg). All pigs were fed diets mixed with 2 g/kg of chromium oxide to calculate apparent total tract digestibility (ATTD). Fecal sample (1g) from each pen was diluted with 9 mL of 10 g/L peptone broth to evaluate fecal microbiota. All data were subjected to the mixed procedure of SAS for a randomized complete block design with a 2 × 2 factorial arrangement. Interactive effects (P<0.05) of energy and LAFP on H₂S and acetic acid emission were observed at d 42. During d 0 to 14 and d 0 to 42, pigs fed the high-energy diets had greater ADG than pigs fed low-energy diets (P<0.05). During d 15 to 42, pigs fed the diets supplemented with LAFP had greater (P<0.05) ADFI and G:F than pigs fed the diets without LAFP. During d 0 to 42, pigs fed the diets supplemented with LAFP had greater (P<0.05) ADG and G:F than pigs fed the diets without LAFP. Pigs fed the high-energy diets had greater (P<0.05) ATTD of GE than those fed the low-energy diets at d 14. Pigs fed the diets supplemented with LAFP had greater (P<0.01) ATTD of DM than pigs fed the diets without LAFP. Dietary supplementation of LAFP increased (P<0.01) Lactobacillus counts and decreased (P<0.01) E. coli counts compared with pig fed the diets without LAFP at d 14 and 42. At d 42, H₂S and acetic acid emission were increased (P<0.05) in feces from pigs fed high-energy diets. At d 14 and 42, total mercaptans, H₂S and acetic acid, and at d 42, NH₃ emission were decreased (P<0.05) in feces from pigs fed LAFP diets. The results of this study indicates that the beneficial effects of LAFP supplementation on fecal noxious gas emission are more dramatic with high-energy diets.

Keywords: energy density, Lactobacillus acidophilus fermentation product, weanling pigs