Where is there a role for additives in silage?

Introduction

In most Australian situations, wilting will be the first strategy used to ensure successful silage preservation. However, effective wilting is not always possible. Management changes need to be considered in areas where low DM content is a frequent problem.

Selecting later-maturing crops or pastures, and delaying sowing of some crops, may shift the main silage cutting period to later in the season when wilting conditions are likely to be more favourable. During periods of poor weather, it may be possible to delay cutting by 2-3 days until wilting conditions improve.

Where wilting is not possible, silage additives can offer a viable alternative. Situations where there is a clear role for additives are summarised below.

Potential role for silage additives in Australia

Crop and ensiling conditions

1. Low-Dry Matter (DM) forage (nil or short wilt), low- Water Soluble Carbohydrate (WSC) (sugar) content, poor wilting conditions.

2. Low-DM forage (nil or short wilt), high-WSC content, poor wilting conditions.

3. Good conditions for wilting, good silage preservation expected, and silage aerobically stable when opened.

4. Good silage-making conditions, good silage preservation expected, but significant risk of aerobic spoilage during feed-out.

Additive type

• Molasses (with or without inoculant).
• Acid or acid salt. Inoculant (homo-fermentative LAB) or acid or acid salt.

Additive is not essential for satisfactory preservation. There is some evidence that inoculants (LAB) may improve silage nutritive value.

Inoculant specifically designed to improve aerobic stability, or organic acid salt, or inoculant + organic acid salt. Further research is required to evaluate these additives.

Warning

• Safe use of silage additives is important, particularly when using chemical additives. Follow the manufacturer’s guidelines for safe handling.
• Use protective clothing and equipment.
• Carry water to immediately rinse off any chemical splashing onto exposed skin.
• Avoid working with chemicals in confined spaces, particularly the additives containing volatile compounds.
• Ensure chemicals are safely stored.
• Clean all equipment and machinery after use.