Exploratory analysis of the associations of short-chain fatty acids and their related factors with growth performance in growing pigs using a Bayesian network.

We suggested the causal relationships between daily weight gains (DG) and feed conversion ratios (FCR) of growing pigs, and short-chain fatty acids (SCFA) concentrations in digesta and blood, and SCFA-related factors such as intestinal morphology, SCFA transporters and tight junction (TJ) proteins. Twelve pigs were divided into 5% of rapeseed meal-, beet pulp- or starch-supplemented groups, kept for 21 days, and dissected. Bayesian network showed that factors affecting DG were expressions of sodium-coupled monocarboxylate transporter 1, claudin-1, and Zonula occludens-1 in cecal mucosa, monocarboxylate transporter 1 and occludin in ileal mucosa, and SCFA concentrations in abdominal aortas. Factors affecting FCR were type of diet, villous height in ileum, SCFA concentrations in ileal veins and cecal digesta. Greater DG may be associated with stimulation of SCFA transportation and regulation of TJ functions, whereas reduced FCR appears to be linked to villous elongation and stimulation of SCFA production in the intestine.