Hay, Haylage and Silage: What’s the Difference?

activity and just like conventional hay bales that are baled in excess of 12 percent moisture heat generation to occur. Forage that is ensiled too dry is a fire risk and can have reduced feed quality due to heating within the bale.
The differences between haylage and silage
Haylage and silage are both ensiled forages but the difference between them is moisture content. In general haylage has a moisture content of between 15 percent to a maximum of 40 percent 60 to 85 percent DM. Silage has a moisture content of more than 40 percent DM less than 60 percent. Both haylage and silage can be found in plasticwrapped round bales. In silage with the higher moisture content the preservation of the forage is as a result of the fermentation of the sugars in the grass under anaerobic conditions. This results in a pH drop. In general a good grass silage in a round bale should have a pH of less than 5. In haylage there isnt sufficient moisture to allow for as much fermentation as in silage. The pH of a haylage round bale will be above 5 on a pH scale of 14. The preservation of the forage in haylage comes from the low moisture content which prohibits microbial growth
It is possible to have a hot spot in either haylage or silage round bales. A hot spot is an area within the bale that is inconsistent with the rest of the bale. The feed in this spot may be completely rotten or poorly fermented. Hot spots are usually a result of contamination of the forage with either soil animal manure or dead animals such as mice that may have become caught up in the harvesting equipment. In the anaerobic conditions of a fermented feed this can provide a potential health risk to horses because of the secondary bacteria that can grow. For this reason clostridial organisms like botulism are a risk in feeding fermented feeds to horses.
Do all round bales contain ensiled forage? 
All round bales that are wrapped in plastic are either silage or haylage. The plastic is commonly white or light green but can be black as well. The plastic wrap on the round bale provides the anaerobic environment necessary to allow the preservation of the forage through fermentation.
It is extremely important that all round bales fed to any livestock species be wrapped with sufficient layers of plastic.