Effects of xylanase on growth performance, nutrient digestibility, serum metabolites, and fecal microbiota in growing pigs fed wheat-soybean meal-based diets.

This experiment investigated the effects of xylanase on growth performance, nutrient digestibility, serum metabolites, and fecal microbiota in growing pigs fed wheat-soybean meal-based diets. Seventy-two crossbred pigs (Duroc × [Landrace × Large White]) pigs (body weight of 23.30 ± 1.51 kg) were allotted two treatments with six pens per treatment and six pigs per pen. The diets were a wheat-soybean meal-based diet (Control group) and a wheat-soybean meal-based diet supplemented with 500 U/kg xylanases (XYL group). The experiment was divided into two periods (phase 1: days 1 to 35 and phase 2: days 36 to 70). Xylanase improved G:F during phase 1 and the entire experiment (P < 0.05) and tended to improve G:F during phase 2 (P = 0.09). Compared with the control group, pigs in the XYL group had greater apparent total tract digestibility of dry matter, organic matter, and gross energy on days 35 and 70 (P < 0.05) and had greater apparent ileal digestibility of amino acids (histidine, lysine, methionine, and serine) on day 70 (P < 0.05). The fecal microbiota in the XYL group contained greater abundances of g_Terrisporobacter, g_Lactobacillus, g_Clostridium_sensu_stricto_1, and g_Romboutsia than the Control group on day 70. Xylanase increased the fecal Lactobacillus populations on day 35 (P < 0.05). On days 35 and 70, xylanase reduced the fecal E. coli populations (P < 0.05). Supplementing xylanase to wheat-soybean meal-based diets collectively improved fecal microbiota, and nutrient digestibility, thereby improving growth performance in growing pigs.