As another silage season approaches, now is a good time to start preparing for a safe silage season. Unfortunately, when most producers are asked what silage and safety mean to them, their answer usually revolves around silage pile or bunker safety.
We need to start thinking about an all-encompassing safe silage season that starts with harvesting the crop in the field and ends with silage delivery to the feedbunk. As dairies grow in size, so do the number of employees and contract laborers involved.
However, as the number of people required to run and maintain a dairy is increasing, the level of agricultural experience and on-farm skills of these people is decreasing. This makes education and training of employees and contract labor on farms that much more important.
When we begin to prepare for a safe silage season, we must ask ourselves, “Who needs to be trained and on what specific tasks or topics?” Some key topics for training and education are silage inoculant selection, application of inoculants and silage feedout.
Those who need to be educated are all employees involved in pre- or post-harvest silage activities, such as chopping, packing, covering, tire removal and feedout.
Before we delve into how to accomplish a safe silage season, let’s take a step back and review the objective of ensiling feed. Ensiling is a means of harvesting a large amount of forage in a short period of time and storing it in a way that preserves the nutrient value, limiting spoilage and contamination, so the feed can be fed out slowly over a long period of time.
While using a silage inoculant is an easy way to ensure proper preservation of forages, choosing an inoculant is not always easy. There is a wide range of inoculants available on the market today, but they do not all achieve the same goal. To optimize preservation of forages, one needs an inoculant best suited for the crop characteristics and moisture of the feed being harvested, as well as taking into consideration storage structure, achievable packing density and rate of feedout.
Farmers may find more than one inoculant brand intended to be used in the conditions they will be harvesting, so how does one decide which brand to select? First and foremost, ask for the research. The fermentation activity of the bacteria in inoculants is strain-specific, so make sure the research is specific to the product and specific strains used.
Keep in mind, the right inoculant can only do its job if the bacteria are viable (alive) when applied to the forage. Don’t forget to take into account the necessary storage conditions for the inoculants being considered and make sure the operation can comply with these requirements.
For an inoculant to work, it must be applied correctly to the crop. This starts with using the right applicator for the product. One major consideration when deciding on how to apply the inoculant is to assess the water temperature in the applicator.
Some harvesters have built-in inoculant tanks used for inoculant application or storing water for add-on applicators. However, the position of these tanks often results in the water being heated to temperatures beyond safe ranges for the bacteria to survive. If bacteria are boiled to death before being applied to the crop, the convenience of the water tank or applicator becomes irrelevant.
Starting with cool water and maintaining low temperatures in an externally mounted applicator will help ensure the bacteria are alive when applied to the forage.
Maintaining good applicator hygiene is critical on all applicators. The attributes that make an inoculant good for ensiling are also the same traits that make for a dirty, clogged applicator. The bacteria in an inoculant want to grow and survive. They will happily start to proliferate and create a biofilm in the body and tubing of the applicator.
If a farmer allows a biofilm to build up in their applicator, they are putting themselves at risk for two issues. The biofilm provides a surface for foreign bacterial contaminants that may come from the water or soil to grow. These bacteria may have a negative effect on silage fermentation.
The biofilm can also physically block the tubing of the applicator, restricting the flow and therefore altering the application rate. Maintaining a clean applicator will ensure the bacteria applied are the bacteria you intended and are being applied at the rate intended.
The final topic to bear in mind to achieve a safe silage season is managing safe, clean feed for your cattle. Here, our goal is to enact practices both during packing and feedout that prevent or reduce contaminants like mold, yeast and toxins. During packing, a plan should be made ahead of time for how much space is required to create piles and bunks with adequate packing densities.
By increasing packing density, and therefore reducing the oxygen in the pile, we reduce the risk of yeast and mold growth. Pile size should also be determined based on the amount of silage that will be fed out. The longer a silage face is exposed, the greater the risk of spoilage.
Even when a pile is put up under ideal conditions, and front-end fermentation was successful, there is still an opportunity for spoilage to occur at feedout, making the silage less safe for cattle. If feeding from a covered pile or bunker, tires and plastic should only be removed to reveal no more than three days of feed.
Longer exposure to oxygen increases the risk of oxygen-loving yeasts and molds. This is seen in the form of a dark crust on the outer layer. Care should be taken not to feed this dark crust, as it can contain high levels of molds, yeast and toxins.
It may seem intuitive to remove the silage that is clearly discolored, but it is important to remove an additional 6 to 12 inches below the crust, as this is where the live spoilage micro-organisms are living. Like the shell of the bunk, the face of the silage bunk can become subject to spoilage when exposed to oxygen.
Face management should be a top priority. A farmer’s goal should be to achieve a flat surface and thereby reduce the amount of surface area exposed between feedout periods. As oxygen will begin to permeate deeper into the face over time, it is ideal that at least 6 to 12 inches of the entire face are fed out daily, depending on packing density.
As a farm owner or manager, one may be reading this and thinking, “Tell me something I don’t know.” However, the real key to achieving a successful, safe silage season is: Every single person who’s a part of pre- and post-harvest needs to be trained and educated on these topics.
Every employee needs to be trained on not just “what” their duties are, but “why” they should and should not perform certain actions. During the pre-harvest phase, remember: Both farm employees and contract labor (such as custom-chopper employees) on a farm should be educated on the rules and expectations involved in chopping, packing and covering the feed.
Likewise during post-harvest, anyone involved in feeding animals or managing the silage piles should be educated on silage pile and bunker safety. These topics should cover items such as the danger of silage gases, the risk of silage faces collapsing and protocols for removing tires and plastic from piles.
By focusing on topics around silage inoculant purchase, application of inoculant and feedout, in combination with educating all employees involved, farmers can be on their way to a successful, safe silage season. There is no doubt safety around the silage pile is important, but it is time to broaden our ideas about silage safety and think about the big picture. 
PHOTO: It is important to remove an additional 6 to 12 inches below silage crust because this is where the live spoilage micro-organisms are living. Photo by Lynn Jaynes.
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Jill Soderstrom Havlin
- Technical Service Manager
- CHR Hansen
- Email Jill Soderstrom Havlin
