While the dairy industry is continually looking to advance practices and become more efficient, these are long-term goals that are not likely to yield meaningful results in addressing the high input costs we’re seeing right now.
There is no magic solution, and if something new is suggested that seems too good to be true, it probably is. As always, the potential to mitigate input challenges comes from the use or adoption of sound management practices. This same concept applies to our management of forages in the harvest and storage phases.
Many opportunities remain to evaluate management practices and look for opportunities to combat increased costs. Evaluate your forage system to develop strategies to ensure quality forage for the entire dairy herd.
Some level of silage shrink is unavoidable, and this is attributed to dry matter (DM) losses through the fermentation process itself. In the best-case scenarios, this is near 10%.
But real opportunity exists in all the other areas of the ensiling process, where both yield and quality are lost. Here are eight tips:
1. Maximize windrow width. When a plant is cut, it continues to respire. This aids the drying process, but it also burns plant sugars and reduces overall dry matter yield. Studies have shown respiration losses of 1% to 7% of dry matter yield.
Plant sugars provide an important food source to the microbes responsible for proper fermentation. Therefore, sugar loss during the drying process can increase the risk of improper fermentation. Respiration losses can be minimized by shortening the time that mowed hay remains in the windrow before harvest.
One of the most significant ways to control this is to maximize windrow width to allow as much exposure to sunlight as possible. Windrows should be a minimum of 80% of cutter bar width and preferably more.
Consider limiting conditioning. Some studies show that no conditioning speeds the drying process for silage, but it is not recommended for dry hay production. It also tends to be more beneficial in alfalfa than high-yield grass.
Increasing cutting height comes with the trade-off of leaving more material in the field, but it can result in higher quality and less overall harvest losses. This outweighs the extra stubble left in the field, particularly in spring when the ground is still wet, which slows drying.
Speeding the drying process has the additional benefit of reducing weather-associated risk. Dry matter losses from hay that is rained on in the windrow are reported to range from 3% to 50%, with as little as 0.2 inches to 2.0 inches, respectively.
The worst-case scenario is when hay is left in the windrow for several days, but still must be ensiled at a lower-than-desired DM. At this point, much of the sugar is gone, but the forage is still too wet, which is a leading cause of poor fermentation and butyric acid production.
2. Limit leaf loss. Particularly with legumes, leaf loss through tedding, raking and harvesting can be significant, reducing both quality and yield.
Losses are generally most significant when the crop becomes too dry before the completion of these tasks. Practices to encourage uniform and rapid drying of the windrow mentioned prior, as well as proper setup of hay-handling equipment, will minimize these losses.
Harvesting at the correct DM will also minimize losses.
3. Use a forage box cover. Losses during the transportation process may seem insignificant, but they can add up, too, particularly in drier silages and when transported at higher speeds, as is more common with the increasing use of dump trucks and tractor-trailers.
Additionally, they can create safety and public perception concerns when forages blow onto roads. Evaluate the use of forage box covers to minimizes these losses.
4. Ensile at proper DM. Storage represents the next challenge and opportunity.
Horizontal silos (bunk and drive-over piles) continue to gain popularity given their logistical advantages, but they can also present the most challenges to maintain forage quantity and quality. Success starts with preharvest planning of how and where forage will be stored with considerations for preserving yield and quality, as well as access to different feeds for different groups of animals.
Ensiling at the proper DM is critical to achieve a proper fermentation. For most silages, a forage DM close to 35% is recommended to optimize yield, quality and fermentation. This can differ by storage structure, with a slightly greater DM favored for upright silos and baleage.
5. Exclude air and water. Oxygen and water, essential to life, are enemies of forage fermentation. It is critical to drive as much oxygen out of the fresh forage as possible to achieve a high density. This is beneficial to maximize the quantity of forage stored and at feedout to prevent oxygen infiltration into the exposed feeding face of the silage.
Exposure to rain can also lead to significant spoilage and should be excluded from the time of ensiling to feedout. When properly set up and maintained, storage options such as upright silos, silo bags and baleage will keep air and water out in a single process.
Studies show that the impact is minimal to the resulting feed if wrapping of bales is delayed as much as 12 to 24 hours. However, this should not be standard practice as it introduces additional challenges for proper fermentation that are avoidable by ensiling more quickly.
Follow manufacturers’ guidelines on plastic layers needed for proper forage preservation. In general, additional layers are recommended for feed that will be stored more than nine months.
The use of high-quality plastic is critical to minimize spoilage around the edges of the bunk or pile. For bunks, the use of plastic lining on the walls is highly encouraged to reduce oxygen infiltration. Oxygen barrier plastics, ideally a separate sheet layered under the standard black-and-white plastic, result in a substantial return on investment to reduce shrink losses.
Minimizing spoilage under plastic presents another opportunity to minimize the safety risk associated with removing spoiled feed at feedout as there is little to no spoilage to deal with.
Ensure adequate weight (tire sidewalls, sandbags) is used to cover the entire surface area, paying extra attention to edges and seems.
6. Use silage inoculants wisely. When used as directed, inoculants can enhance the fermentation process and stability of silage, but should not be considered a solution for problems associated with improper harvest and storage management.
Ask for data to support the efficacy of the product, and make sure to compare products based on actual concentration of active ingredient.
Also, determine where the risk and opportunities are. “Front-end” products are associated with microbes that are beneficial to fermentation and can aid in achieving a proper fermentation. “Back-end” products aid in feed stability at feedout. While effective, they do have a “DM cost” as their activity in the silage results in a small loss of DM. This can be a positive trade-off when concerns around feed stability at feedout are unavoidable.
7. Minimize exposure at feedout. Efforts should be made to minimize the amount of silage exposed to air during feedout and to size feedout faces appropriately to achieve an adequate rate of feedout.
A minimum feedout rate of 4 to 6 inches per day is often referenced. This rate may be adequate in the winter months, but should be considered a minimum and may not be adequate during the summer months.
Avoid scenarios where piles are “split” and an exposed face is left for extended periods of time. Silage face management defacers and rakes have become prevalent on farms and aid in maintaining a smooth face that will minimize surface area exposed to air. However, regardless of equipment used for removing silage, management and technique are critical.
Silage should always be removed from top to bottom to minimize any excess movement of existing silage that would allow air infiltration. Equipment should be sized to reach the top of the silage face, and the face should never be undermined as it significantly increases the risk of avalanches.
8. Be safe! Large bunks and piles present additional safety risks at feedout. Only the silage removal equipment should be near the silage face.
Avoid working near the top edge of the face by keeping tire and plastic removal ahead of feedout, and minimize any spoilage that would need to be removed. If working around the top of the face is necessary, use harnesses or portable railings attached to feedout equipment (tractor, loader, skid steer, telehandler).
Finally, never work in this area alone.
Lawrence is a dairy forage systems specialist with Cornell Pro-Dairy. Kuck is the agriculture program educator with Cornell Extension in Cayuga County.