Experts weigh in on the viability of silage wrap for baling.
In the last few years, there has been a proliferation of products being sold as materials that can help prevent spoilage losses from ensiling high moisture corn or other crops like hay and grasses. The primary idea that underlies this is that some oxygen barrier is needed in the silage to prevent moulds from taking hold and growing, destroying valuable nutrients. Some examples of these products are listed below.
- Oxygen Absorbers/Sealers
- Bags with purging compound or desiccant
- Products containing potassium permanganate
- Products containing sacrificial CO2
Oxygen absorbers and sealers are a technology that your grandparents might have used to preserve fruits and vegetables in canning jars. Bags with purging compounds and desiccants are widely used in other industries to store and ship consumables such as pharmaceuticals, foods, and other items. And potassium permanganate and CO2 have been used to preserve other crops such as hay for many years. For the most part, they all sound pretty good when you read about them on their website or in their sales literature.
However, the claims made about these products appear very appealing when you find out that corn silage can lose up to 33 pounds of dry matter for every 1% of organic matter lost to moulds. To put it another way, a loss of only 3.3% total moisture content can destroy over one third the weight of the original crop!
Fortunately, there is an easy solution to this problem. Dairy farmers have used NETWRAP silage wrap for decades to protect their high moisture corn silages from the mould during the critical period after filling and before ensiling. The best description of how it works is that, when applied to moist silage, silage wrap helps seal the product, preventing oxygen exchange with the outside air. As a result, aerobic moulds cannot grow inside or outside the bale.
Silage wrap is a thin sheet of polyethylene plastic that has been perforated with small holes to allow water vapour and oxygen to escape during the critical early stages of ensiling. A silage wrap is laid on top of the silage pile, close enough to the sides so that a “breathable” net can still be formed with less permeable sheets of plastic.
Once airflow has been restricted and aerobic moulds have had a chance to die from lack of oxygen, there is no reason for concern because the silage pile will stop producing carbon dioxide. At this point, the bale can be wrapped with a thicker sheet of plastic or netting to exclude oxygen from the outside air completely.
The only other consideration is that it may be necessary to have someone on hand to shuffle down the sides of the silage pile as it is being filled to keep it in close contact with the plastic wrap.
If you sell your dairy’s high moisture corn for feed, you owe it to yourself and your customers to compare NETWRAP silage wrap versus other alternatives. While they might look more expensive upfront, silage wrap is the less risky path when compared to oxygen absorbers or bags filled with a desiccant compound.