<p>Principal component analysis (PCA) of microbial metabolite profiles in digesta samples collected from different sections of the gastrointestinal tract of horses receiving one of four rations.</p>

Sections: PNG, gastric pars nonglandularis (dark orange); PG, gastric pars glandularis (light orange); CAE, caecum (royal blue); CVD, colon ventral dextrum (light blue); CVS, colon ventral sinistrum (steel blue); PFL, pelvic flexure (turquoise); CDS, colon dorsale sinistrum (light lavender); CDD, colon dorsale dextrum (purple); CTR, colon transversum (pink); REC, rectum (dark purple).

Rations: PST, pasture (24 h/d, n = 4, green); HAY, hay <i>ad libitum</i> (n = 8, yellow); OS1, hay <i>ad</i> <i>lib</i><i>itum</i> and oats at 1g starch/kg BW/meal (n = 6, light blue); OS2, hay <i>ad</i> <i>lib</i><i>itum</i> and oats at 2 g starch/kg BW/meal (n = 5, dark blue). Abbreviations: BW, body weight; iso-SCFA, sum of iso-butyrate and iso-valerate; SCFA, short chain fatty acids.</p>