Harvest, storage and feeding conditions can affect the effectiveness of silage inoculants and other additives, warns Limin Kung, University of Delaware dairy nutritionist.

Inoculants aid silage fermentation and additives such as L. buchneri, buffered propionic acid, acetic acid, potassium sorbate and sodium benzoate improve aerobic stability, he says.

But slow packing rates, poor packing densities, delayed fills and inadequate sealing of silage “could all potentially affect the efficacy of a silage additive. Challenges during silo filling could be detrimental to an inoculant – the upper layers of forage will remain poorly packed during the evening hours if filling is stopped. This can result in excessive respiration and high temperatures in the forage mass in those layers.”

During storage, damage to plastic coverings from weather or rodents is likely, and at feedout, low silage removal rates, exposed feeding faces where the air is allowed to penetrate into the silage pile or bunker and extremely hot weather can challenge silage additives.

“When used correctly, various additives can help farmers maintain and sometimes improve the quality of their silages,” Kung says. “However, a variety of factors can interact and affect the efficacy of a silage additive. Additives must be stored and applied properly to maximize their potential effectiveness.”

And they aren’t an alternative to good silage management practices, he concludes.