Grass and Legume Silage Tips
High-quality silage is key to optimizing production on the farm. Check out the following management tips for producing high-quality grass and legume silage.
Effective field maintenance includes:
- Levelling and rolling
- Appropriate fertilizer program
- Monitoring of pH and other macronutrients
- Regular re-seeding
Intensive use, late cuts, winter kill damage and damage caused by animals, trampling and tire tracks, for example, can cause undesirable gaps in the stand. Both DM yields and energy concentrations decrease gradually over time.
The optimal cutting time is just before heading to maximize both quality and yield. Waiting till after this point, as the plant continues to mature increasing the yield but decreasing the quality and digestibility. An early first cut establishes the basis for high quality for all subsequent cuts.
The minimum cutting height is 3 in (alfalfa/legume at least 4 in) but this can vary depending on the crop and the environmental conditions.
A minimum cutting height:
- Promotes rapid re-growth
- Reduces ash and thus increases energy contents
- Reduces the introduction of unwanted spores
Keep the wilting time to a minimum to reach the desired DM of 28-35% DM. Wilting time should be limited to less than 24 hours to minimize energy losses. The longer the material is not in the silo the more DM and sugar losses occur from respiration.
Shortened wilting times:
- Reduces respiration, shatter, and leaching losses
- Prevents carbohydrate losses and promotes crop suitability for ensiling
- Reduces proteolysis and improves protein quality
Excessively wet silages can result in butyric acid fermentation, while excessively dry silages are difficult to compact and therefore are more prone to secondary fermentation and reheating. Adequate compaction can no longer be achieved above 45-50% DM.
The optimum chop length for grass and legume silage is 1/2 to 1 inch. Excessive chop length and higher crude fiber hamper compaction, therefore a shorter chop length is recommended for higher DM material.
Optimum chop length is essential for:
- Precise compaction, efficient silo utilization, and reduced losses
- Improved plant cell digestion and thus more intensive lactic acid fermentation
- Reduced gas porosity after silo opening and thus reduced risk of reheating
- Improved feed intake
An effective fermentation process is promoted by adhering to the fundamental principles of ensiling and can be further enhanced by applying silage additives.
- LAB products can only be effective if they are precisely dosed and applied correctly. Microbes do not move through the forage mass so they must be distributed through the material before packing.
- Apply research-proven bacterial inoculants that are designed for specific forage and DM ranges.
- Use a clean and functional applicator. Rinse daily and sanitize if not being used for several days.
The entry of oxygen into a silage pile causes secondary fermentation and reheating to occur. This results in losses of both DM and energy. The more compacted the silage is, the less oxygen that is able to penetrate the silo face.
Measures for optimal compaction/packing:
- Pack thin layers (no more than 6 inches)
- Higher DM material should have smaller layers
- Max 2-3 mph packing tractor speed
- Packing every layer consistently
- No excess packing towards the ends, as this can cause a pumping effect due to silage springing back
“800 lb” Rule of Thumb – Compaction tractor weight calculation: Multiply the tons of material coming in an hour by 800 and the result gives you the tractor weight needed to achieve proper compaction.
Silage should be covered and sealed as soon as possible after packing is finished.
- Oxygen barrier plastic adheres directly to silage
- The top layer of plastic must be air-tight
- Silage netting or tarps protect films against mechanical damage and provide additional weight
- Half tires should be placed on top of plastic for weight and should not have gaps between tires
- Sidewalls should be covered with sidewall film
The minimum daily removal rate is 6 inches, but more can be taken (especially during the summer months). The overall goal is to remove enough to avoid reheating, but be able to remove a single layer from the entire face. Machines used for removing silage helps to keep the silo face as intact as possible in order to minimize oxygen penetration.
How to prevent secondary fermentation and reheating:
- Create summer silos with smaller faces
- Ensure that the silo face is away from the prevailing wind direction
- Remove as little silage plastic as possible in advance
- Calculate silo size and face removal based on herd size