Abstract This study aimed to evaluate the effects of supplemental Bacillus licheniformis derived-protease in diets on growth performance, apparent total tract digestibility (ATTD), and fecal microbial shedding in post-weaned growing pigs. In total, 90 crossbred (Landrace × Yorkshire × Duroc) weaner pigs with an initial average BW 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 (0 to 1, 1 to 3, 3 to 6, and 6 to 11 weeks). The treatments were: CON, corn-soybean meal based basal diet; PROT, basal diet + 0.05% protease. The basal diet contained 16.32, 15.91, 15.49, and 14.91 MJ/kg digestibility energy respectively and 1.50, 1.40, 1.30, and 1.00% lysine respectively for phase 1, 2, 3, and 4. All data were statistically analyzed by Student’s t-test of SAS 9.4 (SAS Institute Inc., Cary, NC, USA). Variability in the data was expressed as mean ± standard deviation, differences with P < 0.05 were considered to be statistically significant. During phase 3, average daily gain, and gain: feed ratio was increased (P < 0.05) in pigs fed PROT diet compared with those fed CON diet. Pigs fed PROT diet had higher (P < 0.05) ATTD of dry matter and crude protein than pigs fed CON diet. No differences were observed in fecal microflora counts between CON and PROT groups. Dietary supplementation of Bacillus licheniformis derived-protease increased growth performance at phase 3 and increased the digestibility) of dry matter and crude protein (insert mean values for both Con vs Treat) in growing pigs.
Read full abstract