Effects of Bacillus licheniformis derived-protease supplementation, alone or in combination, with valine to low protein diet on growth performance and carcass quality grade in growing-finishing pigs

This study was conducted to evaluate the effects of dietary supplementation of Bacillus licheniformis derived-protease, alone or in combination with valine to low protein diet on growth performance, nutrient digestibility and carcass quality grade in growing-finishing pigs. A total of 180 crossbred ([Landrace x Yorkshire] x Duroc) growing pigs with an initial body weight of 22.56 +/- 1.59 kg were used in a 17-week feeding trial. Pigs were randomly allotted into three treatments: CON, basal diet; PROT, low protein diet with 0.05% protease; PROTV, PROT diet with 0.08% valine. During the finishing phase (wk 7-17) and overall period (wk 0-17), gain: feed (G:F) ratio was increased (P < 0.05) in pigs fed the PROTV diet compared with those fed the CON diet. Although the supplementation of B. licheniformis derived-protease in combination with valine to low protein diet increased the G:F ratio of finishing phase and overall, compared with CON, other indexes of growth performance, nutrient digestibility and carcass quality grade were not impacted. Dietary supplementation with a combination of B. licheniformis derived-protease and valine in a low crude protein diet had no deleterious effects on growth performance, nutrient digestibility and carcass quality grade in growing-finishing pigs.