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Effect of protease on growth performance, intestinal morphology, and inflammatory response of nursery pigs fed corn-soybean meal based diets
A keratinase-based additive, Versazyme (VZ, BioResource International, Inc. Durham, NC), was used as as an exogenous source of protease. The experiment was to evaluate the effect of VZ on growth performance, intestinal morphology, and inflammatory response of nursery pigs fed diets with a higher inclusion of SBM. One hundred-twenty pigs (7.3 ± 0.1 kg) weaned on d 21 were allotted to 4 experimental treatments based on a 2 x 2 factorial arrangement with 2 levels of TID Lys (1.22% and 1.01%) and with or without VZ (0.00 and 0.05%). Diets with 2 levels of TID Lys were achieved by altering the amount of SBM included (24 vs. 30%) during a 2-wk study. Body weight and feed intake were measured weekly. Six pigs from each treatment were selected for blood and tissue sample collection. Ileal digesta were collected to measure viscosity. Dietary 1.22% TID Lys increased (P < 0.05) ADG (267 vs. 215 g/d) and G:F (0.68 vs. 0.58) during the entire 2-wk period compared with pigs fed 1.01% TID Lys. There were interactions (P < 0.05) of TID Lys and VZ for ADFI and ADG during entire 2 wk period indicating that VZ improved ADFI (411 vs. 375 g/d) and ADG (282 vs. 252 g/d) of pigs fed 1.22% TID Lys (30% SBM) diet whereas not for pigs fed 1.01% TID Lys (24% SBM) diet. Viscosity of ileal digesta was not different among treatments. Tumor necrosis factor α (TNF-α) concentration of duodenum and jejunum were not different among treatments. However, VZ tended to decrease (P = 0.055) TNF-α concentration in serum. In addition, an interaction (P < 0.05) between VZ and TID Lys in serum malonedialdehyde (MDA) indicated that supplementation of VZ reduced serum MDA concentration at 1.22% TID Lys. Microscopic examination of both duodenum and jejunum also showed an interaction (P < 0.05) between 2 treatment factors, reflecting that supplementation of VZ increased villus height:crypt depth ratio at 1.22% TID Lys. Results suggested that VZ had positive effects on growth performance, systemic lipid peroxidation, inflammatory responses and intestinal development of nursery pigs when dietary TID Lys level was 1.22% (30% SBM).
Keywords: keratinase, nursery pigs, soybean meal, TID Lys