During the transfer of silage to another structure, oxygen is re-introduced into the silage and yeast can become active causing the silage to heat up. Corn silage or small-grain silage, because of their high yeast counts and available sugar, are often prone to heating during a silage transfer. This tendency to heat during a silage transfer is also prevalent in grass or legume silage that did not ferment well. Because of the introduction of oxygen into the transferred silage, we suspect that there is some loss of both DM and nutritive value. The severity of loss depends on the type and quality of silage transferred, and the transfer process.
Silage is less prone to heating during transfer and feed-out in cold weather.
Limiting silage transfer and the feeding of transferred silage to the late fall, winter, and early spring months helps reduce the risks associated with transferring silage. There are a number of propionic acid based additives that reduce the growth of yeast and molds when added to silage and thereby lessen the risk associated with transferring silage. These products often contain some acetic acid or benzoic acid to make them more effective against yeast. Since these are buffered-acid products, corrosion of equipment is not a concern. Unstable silage that is prone to heating upon exposure to oxygen is not a good candidate for transfer.