Wrapping hay bales, often referred to as making baleage or silage, is a method of preserving forage by sealing it in plastic film to create an anaerobic environment, allowing for fermentation. This process is crucial for maintaining the nutritional quality of the forage, especially when it's harvested at a higher moisture content than traditional dry hay.
Understanding Hay Bale Wrapping
Wrapping hay bales is a specialized technique used to produce baleage, a highly nutritious feed that undergoes fermentation. Unlike dry hay, which is cured to a low moisture content, hay for baleage is typically baled when it's significantly wetter. This method allows farmers to harvest forage more quickly, reduce dependence on dry weather windows, and often results in higher quality feed with better palatability and digestibility for livestock.
Why Wrap Hay?
- Nutrient Preservation: Anaerobic fermentation preserves more nutrients, especially proteins and carbohydrates, compared to field-dried hay.
- Reduced Weather Risk: Forage can be baled at higher moisture content (typically 40-60%), reducing the drying time needed and minimizing exposure to unpredictable weather.
- Increased Palatability: The fermentation process can improve the taste and aroma of the forage, making it more appealing to animals.
- Less Leaf Shatter: Handling wetter forage results in less loss of valuable leaves during baling.
The Process of Wrapping Hay Bales
The wrapping process typically involves several key stages, from cutting the forage to storing the wrapped bales.
1. Cutting and Wilting
Forage (grasses, legumes, or a mix) is cut and allowed to wilt in the field. The goal is to reduce the moisture content to an optimal range, typically 40-60%. This is considerably wetter than hay destined for dry storage. Wilting too much can hinder proper fermentation, while too little can lead to spoilage.
2. Baling
Once the desired moisture content is reached, the wilted forage is baled. Both round and large square balers can be used. It's important to create dense, well-formed bales to minimize trapped air, which is detrimental to the fermentation process.
3. Wrapping
This is the critical step where the baled forage is sealed in specialized plastic film. The wrapper will typically come behind the baler, meaning bales are formed first and then individually or collectively wrapped shortly after.
- Timing is Key: Bales should be wrapped as soon as possible after baling, ideally within 2-4 hours. Delaying this step can allow undesirable aerobic bacteria to grow, compromising feed quality.
- Wrapper Types:
- Individual Wrappers: These machines pick up a single bale and rotate it while applying layers of film. They can be stationary or mobile, often towed behind a tractor.
- Inline Wrappers: These machines line up multiple bales end-to-end and wrap them together in a continuous tube of film. This is often more efficient for large volumes.
- Film Application:
- Plastic Film: Specialized bale wrap film is used. It's typically white, green, or black, designed for UV resistance and high stretchability.
- Number of Layers: A minimum of 6 layers of film is generally recommended for optimal sealing and oxygen barrier, with 8 layers often preferred for better protection, especially for longer storage or rougher handling.
- Stretch and Overlap: The film is stretched during application (often 50-70%) to create a tight seal and ensure proper overlap between layers, creating an airtight barrier.
| Bale Type | Minimum Layers Recommended | Optimal Layers Recommended | Storage Duration |
|---|---|---|---|
| Round Bales | 6 | 8 | Up to 12 months |
| Square Bales | 6 | 8 | Up to 12 months |
4. Sealing and Storage
After wrapping, the bales are removed from the wrapper. If using an individual wrapper, the film is usually cut and pressed onto the bale to create a complete seal. Wrapped bales should then be handled carefully and transported to a suitable storage location.
- Storage Location: Choose a well-drained site away from sharp objects, weeds, and potential wildlife damage.
- Protection: Protect bales from punctures by rodents, birds, or other animals, as any breach in the film will allow oxygen in and spoil the forage. Repairs to film should be made immediately using specialized patch tape.
- Monitoring: Regularly inspect stored bales for any damage to the film.
Best Practices for Quality Baleage
To ensure high-quality baleage, consider these practical insights:
- Moisture Content: Aim for a target moisture range of 40-60%. Too dry (below 35%) can prevent proper fermentation, while too wet (above 70%) can lead to clostridial fermentation, producing undesirable byproducts.
- Rapid Wrapping: Minimize the time between baling and wrapping to reduce exposure to oxygen.
- Film Quality: Invest in high-quality bale wrap film that offers good UV stability, puncture resistance, and stretch.
- Proper Overlap: Ensure each layer of film overlaps the previous one by at least 50% to create an effective barrier.
- Bale Density: Densely packed bales help to expel air, aiding in the fermentation process.
- Careful Handling: Avoid dropping or roughly handling wrapped bales, as this can easily puncture the film.
By following these steps and best practices, farmers can successfully wrap hay bales to produce high-quality baleage, offering a valuable feed source for their livestock.
