Effects of dietary supplementation with Bacillus licheniformis derived-protease on growth performance, nutrient digestibility and fecal microbial shedding in post-weaned growing pigs

An experiment was conducted to evaluate the effect of Bacillus licheniformis derived-protease supplementation on growth performance, nutrient digestibility, and fecal microbial shedding in post-weaned and growing pigs. A total of 90 crossbred (Landrace × Yorkshire × Duroc) weaning pigs with an initial average body weight of 6.61 ± 1.73 kg were randomly allotted into 2 treatments with 9 replicate pens of 5 pigs for a 4-phase feeding trial. The treatments were: CON, basal diet; PROT, basal diet + 0.5 g/kg protease of diets (contained 75000 protease units per gram). During phase 3 (wk 3–6), average daily gain, and gain: feed ratio was increased (P < 0.05) in pigs fed PROT diet compared with those fed CON diet. During phase 3 and 4 (wk 6–11, growing phase), pigs fed PROT diet had higher (P < 0.05) apparent total tract digestibility (ATTD) of dry matter and crude protein than pigs fed CON diet. No differences were observed in fecal microflora between CON and PROT groups. In conclusion, dietary supplementation of Bacillus licheniformis derived-protease increased growth performance in post-weaned pigs and increased the digestibility of dry matter and crude protein in post-weaned and growing pigs.