How do inoculants differ?
Inoculants contain different species of bacteria as well as different strains of the same species. Bacterial species differ in the same way humans (species Homo sapiens) differ from cows (species Bos taurus). But Holsteins, Jerseys and Herfords, although all the same species, are very different in their characteristics. Think of them as being equivalent to different strains of a particular bacterial species. For instance, there are many different strains of the species L. plantarum, eg MTD/1, and they all have very different characteristics.
Inoculants designed to improve the initial fermentation nearly all contain Lactobacillus plantarum as this species has been shown to be particularly good at bringing about a rapid silage fermentation. But most strains of L. plantarum don’t start working until the pH has fallen to below 5.5 so to get the fermentation started other ‘helper’ species, eg Streptococcus faecium or Pediococcus, need to be included. Sometimes more than one strain of a particular species is also added as these may have different characteristics.