Biochemical and microbiological properties of a cereal mix fermented with whey, wet wheat distillers’ grain or water at different temperatures

Population Diversity of Yeasts and Lactic Acid Bacteria in Pig Feed Fermented with Whey, Wet Wheat Distillers' Grains, or Water at Different Temperatures

“…One concern is that yeast metabolism can convert starch into alcohol and carbon dioxide, which may result in high ethanol contents and losses of energy due to carbon dioxide production (5). However, in spite of high yeast CFU numbers during fermentation, we previously found only low levels of ethanol and small losses of weight in the feed (20).…”

“…Using these by-products to produce liquid feed avoids wasteful disposal and can thus decrease costs and the environmental burden (5,31). Whey and wet wheat distillers' grains may contain high numbers of microorganisms that can also positively stimulate the development of a beneficial microbial population in feed (20,30).…”

“…The final hygienic and nutritional properties of the feed will depend on the substrates and fermentation process used (4,20). Fermented wet feed reduces the pH and the number of coliform bacteria in the animal gastrointestinal tract (9,24,30).…”

“…The proliferation of spoilage organisms and food-borne pathogens can be prevented by low pH and high concentrations of lactic and acetic acids (2)(3)(4)38). Lyberg et al (20) found that the pH decreased to approximately 4.0 during the first 3 to 5 days of feed fermentation and that this reduction reduced the levels of enterobacteria in the fermented feed. The reduction of pH in liquid feeds by fermentation would therefore be a cost-effective method of reducing enteropathogens and spoilage organisms in the diet (9).…”

“…We recently performed an analysis of chemical parameters in different fermented feed mixtures, together with a quantitative analysis of the microbial populations (20). However, very little is known about the species-level identities of the organisms involved.…”