Now that corn silage harvest is complete, it’s time to size up your results. Fermentation analysis is a useful tool to help evaluate all factors that contribute to successful silage-making.

“A silage fermentation analysis can provide a benchmark to help you improve your corn silage production process,” says Phil Krueger, Mycogen Seeds forage nutrition specialist. “Use this year’s data to plan ahead and adjust your management as needed to ensure you harvest the highest-quality silage next year.”

Here are measurements in a typical silage fermentation analysis and what they might indicate:
• Dry matter (DM). Corn silage should be between 32 percent and 37 percent DM. Silage harvested too wet often has less than 30 percent DM and may decrease intake. Corn silage with more than 37 percent DM likely was harvested too dry and has greater potential for oxygen to penetrate the exposed silage surface, increasing spoilage.
• Total acids. When making silage, the goal is to reduce oxygen and increase acidity rapidly so lactic acid bacteria can grow to stabilize and preserve the silage. After fermentation, total acids should be less than 10 percent of the forage DM. Silage that is too wet often undergoes extended fermentation, resulting in higher total acid content. Silage that is too dry may not have enough total acids to remain stable when re-exposed to oxygen at feedout.
• pH. Fermented corn silage pH should be between 3.7 and 4. Values less than 3.7 may indicate the silage was harvested too wet, while a pH greater than 4 could mean the silage was ensiled too dry.
• Titratable acidity. Combined with other analyses, titratable acidity can help troubleshoot intake challenges. Silage ensiled too wet likely will have a titratable acidity above 10 milliequivalents per gram (meq/g). Silage with titratable acidity under 5 meq/g may spoil faster than you’ll be able to feed it.

Discuss fermentation analysis results with your nutritionist. If results uncover areas for improvement, begin planning now to fix the problems.