Effects of Platycladus orientalis Leaf Extract on the Growth Performance, Fur-Production, Serum Parameters, and Intestinal Microbiota of Raccoon Dogs

SIMPLE SUMMARY: The raccoon dog is one of the most important fur-producing animals. In recent years, due to the gradual ban on the use of antibiotics as growth promoters in various countries, the cost of raccoon dog farming has risen. Plant extracts are considered potential alternative products because they are completely natural, cost-effective, and abundant in various biologically active ingredients. Platycladus orientalis leaves are rich in diverse bioactive components such as flavonoids and polysaccharides, which possess high medical and nutritional value. In the present study, raccoon dogs were fed diets containing P. orientalis leaf extract (PLE), and their growth performance, fur quality, serum parameters, and intestinal microbiota were examined. The results indicated that supplementation with appropriate PLE enhanced growth performance and fur quality while also promoting the intestinal health of raccoon dogs. This research highlights the promising potential of PLE as a valuable feed additive for fur animal production. ABSTRACT: Platycladus orientalis leaves are rich in flavonoids and polysaccharides, which offer high medicinal and nutritional benefits. This study aimed to investigate the impact of P. orientalis leaf extract (PLE) on the growth performance, fur quality, serum parameters, and intestinal microbiota of raccoon dogs. Sixty healthy male black raccoon dogs, aged 85 (±5) days, were randomly assigned to four groups and fed a basal diet supplemented with 0, 0.25, 0.50, and 1.00 g/kg PLE for 125 days (designated as groups P0, P1, P2, and P3, respectively). The results revealed that the raccoon dogs in group P1 exhibited increased average daily gain and underfur length while showing a decreased feed/gain ratio compared to group P0 (p < 0.05). However, the heart index in group P2 was significantly lower than in group P0 (p < 0.05), and the kidney index and serum alanine aminotransferase activities in group P3 were higher than in groups P2 and P0 (p < 0.05), suggesting potential adverse effects at higher PLE dosages. Notably, dietary PLE supplementation led to a reduction in serum glucose concentrations (p < 0.05), which may have implications for glucose regulation. Furthermore, the study explored the impact of dietary supplementation with 0.25 g/kg PLE on the raccoon dogs’ intestinal microbiota using high-throughput sequencing. The results showed significant alterations in the microbial community structure, with a notable decrease in the abundance of Prevotella copri in response to 0.25 g/kg PLE supplementation (p < 0.05). In conclusion, supplementing raccoon dogs’ diet with 0.25 g/kg PLE can lead to improved growth performance and a positive influence on the intestinal microbiota. However, caution should be exercised regarding higher dosages, as they may have adverse effects on certain parameters. As a result, PLE holds promise as a potential feed additive for fur animal production.