Additive microbial agents add rather than replace those of natural origination. The goal would be : 1. to minimize those naturally occurring (e.g. don't kick up dirt into hay when baling); 2. to maximize distribution apply additives during accumulation before hay compacts with appropriate nozzles, pressure, and liquid volume to get good coverage; and 3. to keep hay from heating which obviously degrades quality while allowing natural microbials to multiply quickly. For a general guide to microbial products vs. organic acids and anhydrous ammonia see: http://www.midwestforage.org/pdf/209.pdf.pdf. You may actually learn more by creating just the opposite effect--that is what agents at what moisture multiply rather than decrease preservation. Refer to my 2014 patent "Systems and processes for producing biofuels from biomass" (#8,641,910) where I harvest green biomass and convert it to pipeable fluids within 24-48 hours without additional moisture added. See: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=8641910.PN.&OS=PN/8641910&RS=PN/8641910