Effects of Enterococcus Faecium on Growth Performance, Blood Parameters, Relative Organ Weight, Breast Muscle Meat Quality, Excreta Microbial Shedding and Noxious Gas Emission in Broilers

This 5-wk study was to determine the effects of Enterococcus faecium (DSM 7134) on growth performance, blood parameters, relative organ weights, breast muscle meat quality, excreta microbial shedding and noxious gas emission in broilers. A total of 816 1-d-old broilers were allocated to 4 groups with 12 replications (17 broilers/pen) according to body weight (BW; 43.2 ± 0.32 g). Dietary treatment groups were: (1) CON, basal diet, (2) T1, CON + 0.05% E. faecium, (3) T2, CON + 0.10% E. faecium, (4)T3, CON + 0.20% E. faecium. On d 1, 21 and 35, BW and feed intake were determined. Digestibility, blood parameters, relative organ weight and breast muscle meat quality were determined at 35 d of age. Excreta shedding of Lactobacillus and E. coli, and noxious gas emission were determined on d 7 and 35. Orthogonal comparison was conducted using polynomial regression to measure the linear and quadratic effects of increasing dietary supplementation of E. faecium with P < 0.05 indicating a significance. From d 21 to 35 and overall, dietary E. faecium supplementation linearly increased (P<0.05) body weight gain and gain:feed ratio (G:F), but from d 1 to 21, there was a linear increase (P=0.046) in only G:F. On d 35, dietary E. faecium supplementation linearly increased (P<0.001, P=0.048, respectively) the digestibility of dry matter and nitrogen, and the relative weight of bursa of fabricius (P=0.041), no differences were observed in breast muscle meat quality, white blood cells, red blood cells or lymphocyte counts. Dietary E. faecium supplementation linearly decreased (P<0.0001, P=0.003, respectively) excreta E. coli counts on d 7 and 35, whereas excreta Lactobacilli counts were linearly increased on d 35 (P<0.001). On d 35, dietary E. faecium supplementation linearly decreased (P=0.002, P=0.001, P=0.013, respectively) excreta NH₃, H₂S and total mercaptans emission, but only H₂S emission was decreased (P<0.001) on d 7. In conclusion, supplementation with E. faecium improved growth performance, the digestibility of dry matter and nitrogen, the relative weight of bursa of fabricius, shifted excreta microbiota by increasing Lactobacillus and decreasing E.coli counts, and reduced excreta NH₃, H₂S and total mercaptans gas emission.