Lacto-Fermentation is a way of preserving and enhancing foods through lactic acid. It's been around way before we've had ways to chill our food, can with high heat or use of artificial preservatives. Examples of lacto-fermented foods we eat: yogurt, sauerkraut, fermented pickles...etc.
Benefits of fermenting chicken feed:
Preserves vitamins AND creates new vitamins. Specifically B vitamins (B1, B3, B12, B9)
Contains numerous helpful enzymes, antibiotic & anti carcinogenic substances
Promotes growth of healthy flora through intestines
Removes phytic acid (anti nutrient in grains that binds up minerals and prevents those minerals from being absorbed in the digestive system), thus allowing more minerals to be absorbed.
Increases egg weight and shell thickness
Reduces feed consumption = less feed = saves $$
Less chicken waste & what does come out is more solid and not as smelly
Increases growth rate (If you're raising meat chickens this is exactly what you want)