Silage bales are an expensive commodity therefore protecting them should be a priority for farmers, according to Caitriona Mullin, North East Business Manager with Volac.
With an estimated 13m bales being made in Ireland, a 10% loss of this valuable fodder is equivalent to €40m, she said.
Teagasc studies carried out across 35 farms in Ireland found 40% of silage bales examined were visibly damaged.
Bird and cat damage accounted for 35% and 17% respectively. Only 4% of damaged bales were repaired, the studies show.
Damage to the bales via holes and tears can be caused very easily by a variety of components birds, rodents, cats, dogs and machinery.
Furthermore, Mullin said that any holes that occur no matter how small will allow air to enter encouraging growth of aerobic bacteria, moulds and yeasts.
She advises that any visible signs of damage must be repaired immediately in order to prevent further loss of quality and dry matter.
Birds and vermin such as rats are a major cause of damage to baled silage and it is most common if bales are left in the field after wrapping.
A newly cut field of grass uncovers a feast day for birds providing them with very easy access to their next meal – insects, worms, etc. Bird damage also occurs very easily in storage, she said, where the bales are stacked with no form of protection such as netting.
External damage caused by birds etc is recognisable by the presence of holes along the tops and sides of the bales, the birds pierce the film straight through all the layers of plastic into the silage.
If bales of silage are wrapped at baling or very soon after baling the amount of air trapped in the bale is “used up” within an hour or so leading to anaerobic (no air) condition, according to Mullin.
If the harvesting and storage conditions have been favourable (fast wilt to 40% – 50% dry matter content, no holes in plastic), she advises that a desirable fermentation will occur and mould will not grow.
10 steps to take in order to reduce damage to silage bales:
1.    Aim to wrap bales straight away after baling to minimise exposure to air.
2.    Move bales away from the freshly cut field as soon as possible.
3.    Transport bales correctly – ensure bale handler and trailers have no sharp edges no matter how small they can easily puncture bales.
4.    Patch any holes/damage immediately.
5.    Store bales in a specially laid out storage site – ground must be well drained, level and free from sharp objects that could puncture the bale wrapping film.
6.    Site location is important ideally is must be away from trees, water courses and very exposed areas.
7.    Avoid stacking bales more than three bales high. Bales with a lower dry matter can be heavier and should be stored in a single layer as they can squash bales at the bottom of the stack.
8.    Stacks of bales should be covered with a protective net such as Volac Silanet. Net should be lifted slightly higher than the bales using tyres etc so that it is not in direct contact with the surface of the bales birds will peck straight through it. Must secure the net at ground level also.
9.    Other animals can damage bales also ensure farm and domestic animals such as dogs and cats are kept away from the bales.
10. Check your bales regularly after storage and patch any damage immediately in order to maintain your silage quality.
Volac Silanets are available in two sizes 10mx15m and 20mx15m. If cared for properly are reusable year after year.
Volac recently raised over £10,000 for Northern Ireland Breast Cancer Now. Pictured are Jim Davidson, Trioplast, Noel McGrath, Volac Forage Specialist and Alistair Sampson Volac Business Manager NI.
