The Effect of Dietary Helianthus tuberosus L. on the Populations of Pig Faecal Bacteria and the Prevalence of Skatole.

Jerusalem artichoke contains inulin polysaccharide, which has prebiotic effects and influences the microbiota of the digestive tract. The addition of Jerusalem artichoke in boar diets may decrease the content of skatole and indole, which are the main constituents of boar taint, and may also negatively affect the taste and odor. The objective of this study was to evaluate the effects of different levels of Helianthus tuberosus L. (H. tuberosus) in feed mixtures on performance, carcass composition, the levels of microbiota in faecal samples, and the concentrations of skatole and indole in adipose tissue. The study was performed with 47 crossbred entire male pigs of the Large White _sire × (Large White _dame × Landrace) genotype fed a basal diet with 0%, 4.1%, 8.1% or 12.2% H. tuberosus for 13 days before slaughter. Significant differences in daily weight gain and daily feed intake were found (p = 0.045), with the values being lower in the group with the highest level of H. tuberosus. In addition, increasing levels of H. tuberosus decreased the concentration of skatole in the adipose tissue (p = 0.003). The highest level of H. tuberosus decreased the level of Escherichia coli (p ≤ 0.001) in the faeces. The enterococcal count increased (p = 0.029) in groups with a diet that included 4.1% and 8.1% H. tuberosus. There was also a significant correlation between the concentration of H. tuberosus and the concentration of E. coli (p < 0.001; -0.64) and the skatole levels in the adipose tissue (p = 0.001; -0.46). Moreover, there was also a positive correlation between the concentration of E. coli and the skatole levels in the adipose tissue (p = 0.023; 0.33). In conclusion, feeding pigs with H. tuberosus leads to decreased levels of skatole in the adipose tissue. According to the results of our study, a diet with 8.1% H. tuberosus is sufficient for decreasing skatole levels, which could be due to the decreased levels of pathogenic bacteria in the intestines.