In Vitro Study of Caecal and Colon Microbial Fermentation Patterns in Wild Boar (Sus scrofa scrofa)

The aim of this study was to evaluate wild boar (Sus scrofa scrofa) caecal and colon products of microbial activity including short chain fatty acids (SCFA), ammonia and methane concentrations. The in vitro method was applied to caecal and colon contents after 12 and 24-hour incubation with the substrate (wheat bran), or without any additive (control samples). The pH was also measured in each sample. In samples incubated with the substrate, a lower pH was noted as compared to the control (P < 0.001). In terms of the total SCFA concentration, the hindgut microbial fermentation pattern of wild boar was characterized by a high acetate level, followed by propionate and then butyrate at a ratio of 7:1.5:1. Substrate addition decreased acetate molar proportions (P < 0.001) and increased those of butyrate (P < 0.001) as well as propionate (P < 0.05). The total SCFA level in fresh, unincubated caecal samples (128 mmol/kg) was similar to that in the colon (111 mmol/kg). The ammonia concentrations were at the level of 0.8-1.5 mmol/kg of hindgut content and did not differ between the two investigated hindgut parts. Methanogenesis was also similar in the caecum and colon and after 24h was 2.69 mmol/kg and 2.27 for caecal colon control samples, respectively. The substrate increased total gas production and methane concentration (P < 0.001).