Caecum odd-numbered and branched-chain fatty acid composition in response to dietary changes in fattening rabbits

Summary The study aimed to describe the interactions between nutrition and caecal bacteria abundance using odd-numbered and branched-chain fatty acids (OBCFA). Following a 2 × 2 factorial design, 47 rabbits were fed diets with two levels of digestible fibre (DF, 180 vs. 260 g/kg DM) supplemented with soybean oil (SO, 20 g/kg) or not. At 77 days of age, fatty acid (FA) composition was determined in caecal contents. The microbial origin of OBCFA vs. dietary FA in caecal contents was illustrated by clustering of these FA in the loading plots of principal component analysis. The contribution of odd-numbered FA in the OBCFA pattern was increased (p