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Effects of modified yeast cell wall extract on growth performance and health status of pigs fed diets with low level mycotoxins
This study was carried out to determine the effect of modified yeast cell wall extract (YCWE) (Mycosorb A+, Alltech, Lexington, KY) on growth and health of pigs fed diets naturally contaminated with aflatoxin B1 and fumonisin under the FDA regulatory level. One hundred twenty pigs (60 barrows and 60 gilts at 55.69 ± 6.29 kg BW) were randomly allotted to 4 treatments (2 × 2 factorial arrangement) with 10 pens (3 pigs per pen) per treatment, and fed the experimental diets for 5 wk period. Factors were mycotoxin (0 or 150 ug/kg aflatoxin and 19 mg/kg fumonisin) and YCWE (0 or 2 g/kg diet). All diets were formulated to meet or exceed the NRC nutrient requirements. Feed intake and body weight were measured weekly. At the end of 5 wk, 32 pigs representing a median BW of 8 pens per treatment were selected to take blood samples and euthanized to obtain intestinal tissues. Blood samples were obtained to measure the numbers of blood cells, and to separate serum for liver function test, tumor necrosis factor-α (TNF-α), immunoglobulin G (lgG), malondialdehyde (MDA), and 8-hydroxy-2’-deoxyguanosine (8-OHdG). Mucosa from duodenum and jejunum were obtained to evaluate morphology and to measure TNF-α, MDA, and IgG. Data were analyzed using the Mixed procedure in SAS with pen as the experimental unit using treatments and sex as fixed effects and initial BW as a random effect. Mycotoxin decreased (P < 0.05) ADG (1.210 to 0.992 kg/d) at 1 wk, and tended to decreased (P = 0.099) BW (68.4 to 67.5 kg) at 2 wk, without affecting overall growth performance after 5 wk feeding. Mycotoxin decreased (P < 0.05) neutrophil counts (7.28 to 5.83 cell/mL) and serum cholesterol (86.7 to 77.1 mg/dL). The YCWE decreased (P < 0.05) serum 8-OHdG (1.48 to 0.60 ng/mL), and tended to decrease (P= 0.051) crypt depth (285 to 261 µm) in duodenum. TNF-α, MDA, and IgG in serum and intestinal mucosa were not affected by 2 treatment factors. There was no interaction between 2 treatment factors. Collectively, dietary mycotoxin under the FDA regulatory level had minor effects on growth performance and hematology, and supplemental YCWE reduced oxidative stress in pigs indicated by reduced serum 8-OHdG.
Keywords: 8-OHdG, growing pig, growth performance, mycotoxin, modified yeast cell wall extract