Influence of low or high density corn and soybean meal-based diets and protease supplementation on growth performance, apparent digestibility, blood characteristics and noxious gas emission of finishing pigs

Abstract

This study was conducted to evaluate the influence of dietary supplementation of high and low nutrient density diets and protease on growth performance, apparent nutrient digestibility, blood metabolites, and excreta noxious gas emission in finishing pigs. A total of 140 pigs [(Landrace×Yorkshire)×Duroc] with an initial average body weight (BW) of 50.69±1.91kg were used in a 12-week trial. Pigs were blocked and stratified based on sex and body weight in a 2×2 factorial design with the following factors: 1) low or high nutrient density diet and 2) with or without Protease, 125g/t (Prot). Each treatment consisted of 7 replicate pens with 5 pigs (3 barrows and 2 gilts) per pen. Supplementation of protease significantly increased (P<0.05) ADG and G: F ratio during week 6 to12 and the G: F ratio was also significantly increased (P<0.05) overall. Trends in increased (P=0.08, 0.09 and 0.08) ADG was observed in pigs fed high density diet compared with low density diet during weeks 0–6, 6 to12 and overall respectively. Likewise, feed efficiency was significantly increased (P<0.05) in pigs fed high density diets compared with low density diets. A trend in interactive effect between diets and protease was observed for feed efficiency during wk 6–12. The co-efficient of apparent digestibility (CATTD) of DM, N and Energy was significantly higher (P<0.05) in pigs fed protease supplemented diet during wk 12. Nitrogen digestibility tended to increase (P=0.06) in high density diet than low density diet during wk 6. The supplementation of protease in the diet led to significantly higher (P<0.05) level of creatinine during wk 6 and lower (P<0.05) levels of cortisol and epinephrine in blood serum during wk 12. The concentration of creatinine tended (P=0.08) to be higher in high than low density diets during wk 12. The noxious gases were not affected (P>0.05) by density diets and protease. No interactions were observed between the diets and protease for nutrient digestibility, blood profiles and noxious gases emission.In conclusion, dietary supplementation with 125g/t of protease has beneficial effects on growth performance and CATTD. The stress related hormones were also reduced in pigs fed protease supplemented diets. In addition to tendency in weight gain, feed efficiency was improved in pigs fed high density diets than low density diets.