In vitro fermentation characteristics for pigs of hulless barleys differing in β-glucan content

摘要

Isolated non-starch polysaccharides (NSP), especially isolated β-glucan, are reported to haveprebiotic effects in pigs. However, little information is available on their possible functionalproperties when they are still present in the fibrous matrix of whole cereals. Hulless barleys(hB) are rich but variable sources of β-glucan. In order to evaluate their potential as functionalfeeds, an in vitro experiment was carried out to study the fermentation characteristics of 6 hBvarieties and breeding lines varying in their β-glucan content (36–99 g/kg DM) in comparisonto three hulled barleys (HB), two oat groats, three oats and one wheat, taken as reference. Afterpepsin–pancreatin hydrolysis, the ingredients were incubated in a buffered mineral solutionand pig faeces (inoculum). The accumulated gas production, proportional to the amount offibre fermented, was measured for 48 h and modelled. Short-chain fatty acid (SCFA) andammonia concentrations were measured in the fermented solutions. A cereal type effect(Pb0.05) was observed on the fermentation kinetics parameters. Rates of degradation and totalgas productions were higher with hB than with oat (Pb0.05). Differences were also foundbetween hB for total gas production, lag time and rate of degradation (Pb0.01). The productionof SCFA was also higher with hB (6.1 mMol/g DM incubated; Pb0.05) than with hulled barleyand oat (4.9 and 2.9 mMol/g DM incubated respectively). In contrast, oat generated higherammonia (Pb0.05) production (1.4 mMol/g DM incubated, on average) than both hB and HB(1.0 mMol/g). In conclusion, hB are better fermented, produce more beneficial (SCFA) and lessharmful (ammonia) metabolites and have a better potential than other cereal species tomodulate gut microbiota and improve gut health.