Influence of probiotics in different energy and nutrient density diets on growth performance, nutrient digestibility, meat quality, and blood characteristics in growing-finishing pigs

The study was conducted to determine the effects of probiotics (Bacillus subtilis endospore and Clostridium butyricum endospore complex) supplementation and different energy and nutrient densities on growth performance, nutrient digestibility, and meat quality in growing-finishing pigs. A total of 96 pigs with initial BW of 47.50 +/- 1.14 kg were used in a 10-wk experiment. Pigs were randomly allotted to 1 of 4 treatments in a 2 x 2 factorial arrangement of treatments with 2 levels of energy and nutrient density (low and high energy, CP, and Lys) and 0.2% probiotics according to their sex and BW (6 pens, with 2 gilts and 2 barrows/pen). From 0 to 5 wk, ADG and G: F, as well as the apparent total tract digestibility (ATTD) of N and energy, were improved (P < 0.05) in the probiotic groups and in the high-energy and high-nutrient-density groups. From 6 to 10 wk, ADG and G: F, as well as the ATTD of DM, N, and energy, were increased (P < 0.01) when pigs were fed the high-energy and high-nutrient-density diets. Pigs fed the probiotic supplement or the high-energy and high-nutrient-density diets had increased (P < 0.01) ADG and G: F overall. Moreover, pigs fed the high-energy and high-nutrient-density diets had increased (P < 0.05) meat color scores, marbling scores, drip loss values, pH, and LM area (P < 0.05) compared with those fed the low-energy and low-nutrient-density diets, whereas the probiotic treatment groups had increased (P < 0.01) meat color scores, marbling scores, and redness values. The lightness and yellowness values in the low-energy and low-nutrient-density dietary treatments were greater (P < 0.05) than those in the high-energy and high-nutrient-density dietary treatments. Interactive effects of dietary energy and nutrient density and probiotics were also observed (P < 0.05) on the digestibility of N at wk 10 and energy at wk 5, as well as on meat firmness at the end of the experiment. In conclusion, dietary supplementation of probiotics increased growth performance throughout the experiment and exerted beneficial effects on ATTD. Meat quality was improved when pigs were fed high-energy and high-nutrient-density diets.