Effects of Aspergillus oryzae fermentation extract on in vitro equine cecal fermentation.

The research examines the impact of Aspergillus oryzae fermentation extract on horse’s cecal fermentation under lab conditions. It notes that the presence of A. oryzae can alter fermentation profiles, suggesting the adaptability of horse gut microorganisms to dietary supplements and the possible impacts on digestion.

Research Process

• The study focused on how the Aspergillus oryzae fermentation extract influences the in vitro equine cecal fermentation of soluble starch, amino acids/peptides, coastal bermudagrass hay, and alfalfa hay.
• The cecal contents were collected from a Quarter Horse gelding with a cecal fistula, fed on bermudagrass and grain. This horse was either fed normally (unadapted) or given a dietary supplement of A. oryzae (2g/day).
• The harvested cecal microorganisms were cultured in an oxygen-free environment for 24 hours (for soluble starch, amino acids) and 48 hours (for bermudagrass hay, alfalfa hay).
• The A. oryzae extract was added to these cultures at concentrations of 0, .07, or .7 g/L.

Key Findings

• The fermentation of soluble starch with .7 g/L of A. oryzae resulted in increased concentrations of acetate, propionate, NH3, and L-lactate and a decreased final pH.
• Addition of .7 g/L of A. oryzae to amino acid/peptide fermentations also decreased final pH and increased concentrations of H2, acetate, propionate, butyrate, and total VFA.
• When alfalfa hay or bermudagrass hay was fermented using .7 g/L of A. oryzae, CH4, IVDMD (in vitro dry matter disappearance), and digestion of NDF (Neutral Detergent Fiber) and ADF (Acid Detergent Fiber) decreased.
• .7 g/L of A. oryzae did not inhibit methanogenesis or fiber digestion and L-lactate concentrations were not increased when adapted mixed cecal microorganisms were used (those from horses previously exposed to the A. oryzae supplement).

Implications and Conclusions

• The study signifies that A. oryzae has the potential to affect the cecal fermentation process in horses, leading to potential changes in their digestive dynamics.
• It shows that horse gut microorganisms are likely to adapt to the addition of dietary A. oryzae, which alters their fermentation profile and may consequently affect the nutritional absorption and overall health of the horse.
• The changes in nutrient digestion depending on the addition and concentration of A. oryzae suggest the need for careful consideration when incorporating this fermentation product into equine diets.