Effects of castration on growth performance and cecal microbiota in growing raccoon dogs: an exploratory study

Castration is a common surgical procedure in male farm animals and may affect growth and physiology. However, its effects on growth performance, nutrient digestibility, serum parameters, and cecal microbiota in growing raccoon dogs remain unclear. Therefore, this exploratory study was conducted to evaluate these responses in growing raccoon dogs. Ten healthy raccoon dogs (aged 80 ± 5 days) were randomly allocated to Sham and Cast groups (n = 5 per group). After a 60-day trial, raccoon dogs in the castrated group showed significantly lower final body weight and average daily gain, together with a higher feed to gain ratio (p < 0.05). Castration was also associated with higher apparent digestibility of crude fat and neutral detergent fiber (p < 0.05) and elevated serum cholesterol and triglyceride levels (p < 0.05). In addition, the cecal microbial community structure differed between groups. Compared with the Sham group, the Cast group showed a higher relative abundance of Bacteroidota, a lower Firmicutes/Bacteroidota ratio, and a higher relative abundance of Prevotella (p < 0.05). Cecal acetic acid and propionic acid concentrations were also higher in the Cast group (p < 0.05). In this exploratory study, castration was associated with reduced growth performance, altered lipid-related traits, higher apparent digestibility of crude fat and neutral detergent fiber, and shifts in cecal microbiota composition in growing raccoon dogs. The increased relative abundance of Prevotella and higher short-chain fatty acid concentrations may reflect changes in hindgut fermentation and energy utilization following castration. However, given the limited sample size and the lack of direct functional validation, these findings should be interpreted cautiously and require confirmation in larger and mechanistic studies.