Fermentation is an inconspicuously complex process. Once thought to be a purely chemical reaction, fermentation is the work of hundreds of species of bacteria, yeasts, and molds consuming, excreting, reproducing, and dying off. Each have their own ideal conditions under which they will grow and flourish. By maintaining the right environment and introducing the species you want, you can prevent spoilage and maximize your feed!
Bacteria require the most water to thrive. The bacteria seen in fermentation are in the acetobacter, streptococcaceae, and lactobacillaceae families.1 Most preferred is Lactobacillus plantarum which is a very beneficial bacteria found in many places including human saliva.2 Bacteria can work in two ways. Homofermentative bacteria, such as L. plantarum, turn the sugars in food, specifically glucose, into lactic acid. Meanwhile, heterofermentative bacteria turns glucose into lactic acid, ethanol, and carbon dioxide gas and also produces flavor and aroma compounds.3 It would be best if we could have both, because a wider range of bacteria will create a more diverse nutrient profile.
Lactobacillus used for feed fermentation prefers an anaerobic (meaning ‘without oxygen’) environment. Keeping your feed submerged in water while fermenting will satisfy the bacteria’s need for a very wet environment with little air. Make sure your water is dechlorinated by using filtered water or allowing the chlorine gas to evaporate by leaving your water in an open container overnight before using it for fermentation. Chlorinated water will kill bacteria, as it is intended to do. Lactofermentation is best accomplished at 66.4-71.6 degrees Farenheit.4Yeast requires less water than bacteria, so a drier mix may be dominated by yeasts. Yeasts turn sugars into alcohol, specifically ethanol. We certainly do not want our chickens getting drunk, but if you use enough water and leave the ferment longer, this alcohol will become the food for beneficial acetobacter bacteria to create additional acetic acid. Saccharomyces cerevisae is the best of the yeasts and is found in baker’s yeast although a fair amount of yeast will be picked up from the air naturally. Yeast can help by consuming the air within a closed container to improve the environment for anaerobic bacteria. The presence of yeast in the food also helps with weight gain in chickens and reduces diarrhea.5 Molds can play a beneficial role in fermentation, such as in the ripening of cheese, but there is generally no positive role for mold in fermenting feed for your chickens. Molds cannot tolerate an anaerobic environment – they need air – and so keeping enough water in your container will prevent your food from molding. You may notice mold growing on the sides of a container if the feed slops around. Fermentation reactions work together in a chain. For example, yeasts produce the alcohol needed by acetobacter bacteria to create acetic acid. Generally, bacteria are followed by yeasts which are followed by molds.6 You can see such chaining at work in the production of silage, a long-used fermented feed, just within different strains of bacteria:
When we are fermenting feed for chickens, we want to use plenty of dechlorinated water, keep the feed submerged by adding more liquid when needed, maintain about 67-70 degrees Farenheit, and give the microorganisms enough time to go through all of the stages of fermentation to leave us with an acidic, nutrient-enhanced wet feed. I need to do more experimenting to find a procedure which works for me, but I think the health benefits for my birds are worth the extra effort.
E. faecium growth is the first step in the silage process. […] L. plantarum takes over from E. faecium and finishes off the initial silage process, after which it runs cool. […] L. buchneri takes over from L. plantarum as soon as the silage reaches its lowest pH and converts some of the lactic acid to acetic acid, which inhibits the yeasts that may be there to cause heating on feedout.7
Fermented Feed Posts:
#1: Fermented Feed
#4: Microorganisms at Work (this post)