Effect of Probiotics Supplementation Level on Growth Performance, Blood Parameters and Fecal Metabolites in Nursery Pigs.

Abstract This experiment was conducted to evaluate the effects of dietary supplementation level of probiotics on growth performance, blood variables, and fecal metabolites in nursery pigs. Certain strains of Bacillus subtilis have been shown to reduce the incidence and severity of diarrhea and therefore improve growth performance of nursery pigs. A total of 54 newly weaned piglets were allotted to 3 treatments in 3 replicates with 6 pigs per pen based on body weight, gender, and breed for a 28-d feeding trial. Treatments were: 1) Control: no probiotics supplementation, 2) CERTILLUS 1x: probiotics supplementation at the recommended level, and 3) CERTILLUS 10x: probiotics supplementation at 10 times the recommended level. The CERTILLUS products consisted of two strains of Bacillus subtilis at a low and a high dose of 3.75 × 108 CFU/g and 3.75 × 109 CFU/g supplemented at 0.05% resulting in 1.875 × 105 CFU/g diet and 1.875 × 106 CFU/g diet for the 1x and 10x treatments, respectively. Corn-soybean meal-based diets were used for d 0-14 (Phase 1) and d 14-28 (Phase 2) postweaning. Body weight, blood glucose and creatinine, fecal short chain fatty acid (SCFA) and bile acid concentrations were measured at d 14 and 28 postweaning. Body weight at d 14 postweaning (P = 0.06; 11.98, 12.73, and 12.21 kg for the control, 1x, and 10x treatments, respectively) and average daily gain for d 0 to 14 postweaning (P < 0.05; 0.206, 0.259, and 0.222 kg/d, respectively) were greater in the 1x treatment than the control and 10x treatments although there was no significant difference in growth performance at d 28 postweaning. Blood glucose concentrations were greater in both probiotic treatments than the control treatment at d 14 postweaning (P < 0.05; 95.2, 111.7 and 114.3 mg/dL for the control, 1x, and 10x treatments, respectively). In the fecal SCFA concentrations, the butyrate concentrations were greater in the 1x treatment than the control and 10x treatments (P < 0.05; 36.17, 47.57, and 33.23 µmol/g feces for the control, 1x, and 10x treatments, respectively) and the acetate (120.02, 141.87, and 101.17 µmol/g feces, respectively), propionate (62.95, 71.42 and 55.27 µmol/g feces, respectively), and total SCFA (236.72, 282.23, and 205.80 µmol/g feces, respectively) concentrations were greater in the 1x treatment than the 10x treatment with the intermediate value in the control treatment (P < 0.05). There were no significant differences in fecal bile acid concentrations and blood creatinine concentrations at both d 14 and 28 postweaning. In conclusion, dietary probiotics supplementation to nursery diets at the recommended level could improve growth rate in the early postweaning period and increase fecal SCFA concentrations but not at a high level of supplementation.