Effect of supplementation on growth performance, serum immunity, antioxidant status, and intestinal health in winter fur-growing raccoon dogs ().

Introduction: This study aimed to investigate the effects of supplementation on the growth performance, nutrient utilization, serum biochemistry, immunity, antioxidant status, and intestinal microbiota of raccoon dogs during the winter fur-growing period.

Methods: Forty-five 135 (±5) day-old male raccoon dogs were randomly assigned to three dietary groups supplemented with 0 (group N), 1 × 10 (group L) and 5 × 10 CFU/g (group H) , with 15 raccoon dogs per group.

Results: The results showed that in groups L and H improved average daily gain (ADG) and decreased feed-to-weight ratio (F/G) ( < 0.05). No significant difference was found in nutrient digestibility and nitrogen metabolism among the three groups ( > 0.05). Compared with group N, serum glucose levels were lower in groups L and H ( < 0.05). The levels of serum immunoglobulins A and G in group L were higher than those in the other two groups ( < 0.05), and the levels of serum immunoglobulins A and M in group H were higher than those in group N ( < 0.05). Supplementation with in groups L and H increased serum superoxide dismutase activity, and the total antioxidant capacity in group H increased compared with group N ( < 0.05). The phyla Bacteroidetes and Firmicutes were dominant in raccoon dogs. The results of principal coordinate analysis (PCoA) showed that the composition of microbiota in the three groups changed significantly ( < 0.05). The relative abundance of Campylobacterota was increased in the H group compared to the N and L groups ( < 0.05). The relative abundance of was increased in group L compared with the other two groups ( < 0.05), while the relative abundance of and were decreased in group H compared with the other two groups ( < 0.05). Also, the relative abundance of and was higher in group L ( < 0.05) compared with group H.

Discussion: In conclusion, dietary supplementation with improved growth performance, antioxidant activity, immune status, and improved intestinal microbiota in winter fur-growing raccoon dogs. Among the concentrations tested, 1 × 10 CFU/g was the most effective level of supplementation.