Effects of dietary supplementation of Enterococcus faecium on growth performance, intestinal morphology, and selected microbial populations of piglets

Abstract

The objective of the study was to investigate the effects of dietary supplementation of E. faecium on growth performance and intestinal health of 35- to 70-d-old piglets. Two hundred fifty-five 35-d-old crossbred (Duroc × Landrace × Large White) piglets were randomly assigned to 5 treatments with 3 replicates of 17 pigs per pen. The treatments were basal diet (control), basal diet supplemented with antibiotics (8 mg flavomycin and 90 mg arsanilic acid/kg), and basal diet supplemented with E. faecium preparation (2 × 1010 cfu E. faecium/g) at the dose of 100, 300, and 500 mg/kg diet. The average daily gain (ADG), average daily feed intake (ADFI), gain to feed ratio (G:F), and diarrhea index were determined during the entire experimental period. At the end of the experiment, 6 pigs from each treatment (2 per pen) were euthanized, and the gastrointestinal pH, small intestine morphological traits, and selected intestinal microbiota populations were determined. The ADG and ADFI tended to be improved with the increasing doses of supplemented E. faecium or the added antibiotics (P = 0.053 and 0.072, respectively), while G:F was linearly or quadratically improved (P < 0.05) and the diarrhea index was linearly or quadratically decreased (P < 0.01) as E. faecium supplemented increased. Furthermore, the pH in the stomach, duodenum, jejunum, and cecum decreased (P < 0.05) linearly and quadratically as E. faecium supplemented increased. The villus height and villus-to-crypt ratio (V:C) of jejunum were increased (P < 0.05) in piglets receiving E. faecium preparation in diet than those fed the basal diet and antibiotic supplemented treatments. Supplementation with E. faecium in basal diet increased (P < 0.05) the counts of Lactobacillus spp. in comparison with that of control treatment or antibiotic treatment, while tended to decrease the populations of E. coli and aerobes in small intestine relative to those in control treatment. Thus, inclusion of E. faecium preparation in basal diet could improve G:F and reduce the piglets’ diarrhea index. These effects might be ascribed to the improvement of intestinal health condition, including the improved gut internal acid environment (pH values), increased beneficial selected microbial populations, and better intestinal morphology. Considering all the determined variables, the optimum dietary E. faecium concentration preparation seemed to be about 500 mg/kg in piglet's diet.