Shepherd, Megan L.Ponder, Monica A.Burk, A. O.Milton, Stewart C.Swecker, William S.2016-12-082016-12-082014http://hdl.handle.net/10919/73592The purpose of the present study was to compare digestibility of grass hay, faecal and plasma volatile fatty acid (VFA) concentrations, and faecal bacterial abundance in overweight and moderate-condition mares. Five overweight adult mixed-breed mares and five adult mixed-breed mares in moderate condition were housed individually and limit-fed orchard grass (Dactylis glomerata) hay at 20 g/kg body weight (as fed) daily for 14 d. Forage DM and fibre digestibility were determined using AOAC methods; digestible energy was measured using bomb calorimetry; plasma and faecal VFA concentrations were determined by use of GC and MS; faecal Firmicutes, Bacteroidetes, Fibrobacter succinogenes, Ruminococcus flavefaciens and total bacteria abundance was determined by quantitative real-time PCR using previously designed phylum-specific 16S ribosomal RNA gene primers. No differences in hay digestibility, faecal VFA concentrations or faecal bacterial abundance were detected between overweight and moderate-condition mares. Mean plasma acetate concentrations were higher (P = 0·03) in overweight (1·55 (range 1·43-1·65) mmol/l) v. moderate-condition (1·39 (range 1·22-1·47) mmol/l) mares. We conclude that the higher plasma acetate in overweight mares should be further investigated as a potential link between gut microbes and obesity in horses.e10 - ? page(s)application/pdfenCreative Commons Attribution 3.0 UnportedADF, acid-detergent fibreBCS, body condition scoreBody condition scoreDE, digestible energyDMI, DM intakeDigestible energyFaecal bacteriaHorsesNDF, neutral-detergent fibreOG, orchard grassVFA, volatile fatty acidrDNA, ribosomal DNArRNA, ribosomal RNAArticle - Refereedhttps://doi.org/10.1017/jns.2014.83