Farmers who chose to use conventional black plastic to cover their silage clamps could be losing up to 10% of their crop to aerobic spoilage as well as seeing a 20% loss in dry matter (DM) content. Switching to a modern sheeting alternative can reduce DM losses by more than 10% as well as eliminating spoilage caused by poor clamp sealing.
Producing and preserving a supply of high quality winter silage is critical to profitable dairy and livestock production, yet all too often the final stage of silage-making – sealing the clamp – receives inadequate attention to detail.
“After going to the expense and effort of growing a high-quality sward of silage grass, ensuring that it is cut at the right time and wilted sufficiently before being harvested, ensiled and treated with an additive, many farmers are still cutting corners when it comes to sealing their silage clamps”.
“The temptation to re-use last year’s plastic sheeting often results in silage being stored under a layer of film that is riddled with holes and which will be susceptible to high levels of aerobic spoilage.”
Even using a new sheet of traditional black plastic may not be enough to securely seal the clamp. “Conventional plastics aren’t as airtight as most farmers think and can allow up to 400 cm3/m2 of oxygen to permeate through in a 24 hour period. Silostop sheeting is unique in that it is the only scientifically proven high oxygen barrier film on the market. As such it can cut oxygen ingress to as little as 3 cm3 per square metre.”
Regular black plastic sheeting remains the market’s best selling silage covering based simply on it’s low-cost, with modern alternatives costing considerably more per square metre. However, trials carried out by Silostop show that the additional costs associated with films that effectively prevent air ingress are more than paid for by reducing the amount of silage that is lost to aerobic spoilage. They also pay for themselves by reducing losses of dry matter from as much as 20% for conventional sheeting to less than 8% for modern alternatives (see table below).
Research carried out by Silostop also indicates that mould infection in the upper layer of silage can be eliminated by using an high oxygen barrier film, compared to the presence of up to 15cm of mould infection in clamps covered with a conventional plastic sheet.
At a conservative value of £30 per tonne for good quality grass silage, the top metre of the clamp has a value of £18.00 per cubic metre. Silostop’s ability to reduce inedible DM losses by over 10% equates to a saving of £1.80 per square metre. At a typical cost of less than 36 pence per square metre the sheeting pays for itself in the top metre of the clamp.
Modern sheeting products also offer a range of additional benefits. Products such as Silostop films are considerably thinner than traditional plastic sheets which are typically 125 to 150 microns thick. They are more flexible and less brittle than conventional black plastic and can withstand being walked on without the risk of tearing.
Thinner sheets are also easier to use as they cling to the contours of the silage as they are pulled across the pit. This creates a more airtight seal, especially when used in conjunction with a continuous barrier of weighted gravel bags instead of a haphazard pattern of old tyres.
The use of purpose-made gravel bags has the added advantage of reducing the risk of cows ingesting pieces of tyre wire, thereby cutting veterinary bills and replacement cow costs. They also create the perfect seal resulting in minimal silage loss, improved animal intake and increased productivity.
The final stage of the silage making process is key to ensuring the long shelf-life, palatability, dry matter content and nutritional value of silage. Creating an airtight seal will significantly reduce wastage as well as preserving the feed value of the crop. Investing in an high oxygen barrier film and paying attention to how the clamp is sealed after harvest and whilst being fed out is therefore time and money well spent.