PSV-2 Effects of protease on growth performance, fecal gas emission of 25- to 55-kg pigs fed low or high density diets

Abstract

Volatility in feed ingredient prices prompts animal nutritionists to evaluate alternative methods to control feed costs. The objective of this study was to evaluate the effects of protease in growing pigs fed either high or low-density diets. A total of 140 pigs [(Landrace×Yorkshire)×Duroc] were used in a 6-wk study with an initial BW of 24.1 ± 0.02 kg equally distributed in 7 pens per treatment fed one of the following treatments: High-density diet with 3400 kcal ME/kg, 19.5% CP, and 0.85% SID Lys; High-density diet + 125 g/t Jefo Protease (Jefo, Canada); Low-density diet with 3300 kcal ME/kg, 17.6% CP, and 0.83% SID Lys; and Low-density diet + 125 g/t Jefo Protease. Diets were corn, soybean meal-based with 12% rice bran and 8% wheat bran. Data were subjected to statistical analyses as a completely randomized design using a 2 × 2 factorial arrangement with pen as the experimental unit. Differences among treatment means were determined using Duncan’s multiple range test with level of significance at P ≤ 0.05. High-density diets (P = 0.01) and protease supplementation (P = 0.05) significantly improved G:F in pigs (Table 1) compared to low-density diets and no protease supplementation. NH3 and H2S gas emission tended to be lower (P ≤ 0.10) in diets supplemented with protease. There were no statistical differences (P > 0.10) in initial weight, final weight, ADG, and ADFI. In conclusion, protease supplementation and high density diets improved G:F in 25- to 55-kg pigs.