Nutritional and functional roles of an endo-1,4-β-D-mannanase in young tom turkeys

This study evaluated the effects of increasing doses of β-mannanase (Natupulse® TS) on growth performance, cellular stress, and immune response in turkey toms fed an all-vegetable diet. A total of 1,920 male Hybrid Converter turkeys (40 birds/pen; 12 pens/treatment) were randomly assigned to four dietary treatments (T1 = 0, T2 = 400, T3 = 800, and T4 = 1200 TMU of mannanase per kg feed) in a randomized complete block design. A corn-soybean meal basal diet was fed from 0 to 35 days of age. Feed intake and BW were recorded on day 21 and 35 post hatch for BW gain (BWG) and feed conversion ratio (FCR) calculations. On day 21, ileal samples from five birds per treatment were analyzed for markers of oxidative stress, gut barrier integrity, and inflammation using real-time quantitative PCR. There were no significant differences in all measured performance parameters within the 5-week period, however there was a tendency for longer intestinal length (P = 0.072) in turkeys fed the basal diet compared to enzyme-added treatments. In addition, β-mannanase supplementation reduced (P < 0.05) the mRNA expression of heat shock proteins (HSP60, HSP70, HSP90) in T4 compared to T1. Barrier function genes (CLDN1, JAM3) also showed significant improvements (P < 0.05). The mRNA expression of ileal superoxide dismutase 1 (SOD1), catalase (CAT) and glutathione peroxidase 1 (GPX1) was unaffected by treatments. Additionally, inflammatory cytokines (IL-6, TNFα, IL-4, IL-10) and C-reactive protein (CRP) expression were significantly lower (P < 0.05) in mannanase-fed groups compared to the control group. In conclusion, increasing β-mannanase supplementation (Natupulse® TS) for young turkeys had no significant performance effect but caused an improvement in intestinal physiology, reduction in intestinal inflammation and oxidative stress, with enhanced gut barrier integrity.