Abstract
In recent years, ancient grains have become popular sources of novel carbohydrates and fiber in pet foods. End-products of microbial fermentation (e.g. short-chain fatty acids) have been shown to be beneficial to the canine microbiome and overall host health. However, limited research exists on the fermentation characteristics of these increasingly popular grains. Thus, the aim of this study was to quantify the fermentative characteristics of select ancient grains in vitro using canine fecal inoculum. Five ancient grains, amaranth (AM), millet white proso (MWP), oat groats (OG), quinoa (QU), red millet (RM), were evaluated and compared to cellulose (CEL) and beet pulp (BP). Triplicate samples of each substrate were initially subjected to partial digestion of starch and protein to mimic in vivo conditions. They were then fermented for 0, 3, 6, 9, and 12 hours. All test substrates had acetate concentrations similar to that of BP after 6, 9, and 12 hrs. Amaranth, OG, and QU had significantly greater butyrate concentrations than BP and CEL after 6 hours, with all test ingredients having significantly higher butyrate concentrations after 9 and 12 hours. pH decreased significantly after 6 hours with further decreases seen after 9 and 12 hours for all substrates, except CEL. Amaranth, MWP, OG, and RM showed significantly greater pH reductions than CEL and BP, with QU performing similarly to BP. Overall, ancient grains show a moderate and beneficial fermentative profile with greater concentrations of butyrate compared with BP; a traditional and moderate fermentable fiber source used in pet foods. Future research should evaluate these substrates and their blends on gastrointestinal health and fecal quality in vivo.
In vitro fermentation kinetics of a range of alternative forages and their suitability as forage feeds for horses
