Dietary supplementation of Aspergillus niger-expressed glucose oxidase ameliorates weaning stress and improves growth performance in weaning pigs.

Weaning is one of the most stressful events in the pig's life, which disrupts physiological balance and leads to oxidative stress. It is reported that glucose oxidase supplementation could alleviate oxidative stress in animals by increasing the concentration of antioxidant enzymes in vivo. The purpose of this study was to evaluate the effects of dietary supplementation of Aspergillus niger-expressed glucose oxidase (AN-GOX) on growth performance, nutrient digestibility, faecal microbiota, faecal gas emission and serum antioxidant enzyme parameters in weaning pigs. A total of 120 21-day-old weaning pigs [(Yorkshire ×Landrace) × Duroc] with an initial body weight of 6.54 ± 0.55 kg were used in a 21-day experiment (phase 1, days 1-7; phase 2, days 8-21) with a completely randomized block design. Pigs were randomly divided into 4 treatment groups with 6 replicate pens per treatment and 5 pigs per pen (2 barrows and 3 gilts). Dietary treatments were corn-soybean meal-based basal diet supplemented with 0, 0.01, 0.03 or 0.05% AN-GOX (1000 unit/g). The results of this study showed that average daily gain during days 1-7 and 1-21 and the concentrations of serum glutathione peroxidase and glutathione increased linearly at graduated doses of AN-GOX increased in the diet. However, dietary supplementation of AN-GOX had no effects on the apparent nutrient digestibility, faecal microbiota and faecal gas emission. In conclusion, supplementing AN-GOX to the diet of weaning pigs ameliorated weaning stress, which manifested as the increase in serum antioxidant enzyme levels, thus improving growth performance. The suitable dosage of AN-GOX used in the diet of weaning pigs was 0.05%.