Five basic rules to look after your silage
By Frank Mickan, FJM Agricultural Services
1. Cut earlier than later
If forage is cut early in the season and at or near early canopy closure, these paddocks will usually not miss a rotation. The silage will have very high nutritive value and be very palatable to stock, providing it is not left on the ground for too long. Paddocks will recover very quickly and densely, just as if they had been grazed.
Forage cut three to five weeks later will be less nutritious, more bulky due to increased fibre in the stems and pastures will be much slower to recover with less density. Open pastures are vulnerable to soil and nutrient loss in heavy rains and summer weeds just love bare ground.
2. Harvest in the correct dry matter range
Stack silage should be harvested in the 30 - 35 % dry matter (DM) range and baled silage in the 40 - 45% range. If either is below these ranges a poorer fermentation occurs, often with environmentally unfriendly effluent being produced. In addition, there are losses in DM and quality of the forage during fermentation.
Harvesting forage above their respective ranges will often result in mould and yeast growth in the silage due to too much air being entrapped between the dry material. This results in spoiled silage either left at the stack or in the paddock.
3. Harvest within one to two days
Once mown, pastures continue to respire or “live’ so its nutritive value starts to decline. This reduction in quality increases substantially from day three onwards. So use a tedder soon after mowing or a mower-conditioner to increase the rate of wilting.
4. Seal quickly and airtight
Stacks should be sealed airtight as soon as harvesting is completed. The rolling tractor(s) should have been keeping up with forage delivery. If harvest completion is later in the night, do the final roll then drag on the plastic and place tyres, sausage bags or soil around the perimeter to minimise or preferably, prevent air entering overnight. Rolling the next day just pushes more air into the stack.
Many stacks are covered but not sealed airtight. Mould under the plastic sheet indicates poor sealing. Baled silage should have the stretch wrap plastic applied at baling and no later than one to two hours. The bales must be covered with at least four layers of film, preferably six at the correct pre-stretch (55% or 70%) and with 50% overlap. No windows should be visible as oxygen will infiltrate much quicker than with four layers, leading to mould growth, gas production, spoiled silage, etc.
5. Regularly inspect silage storages damage
Regularly inspect your silage stacks and bales for damage and repair as soon as possible. It is very handy to have a roll of silage specific tape in the ute, mule or four-wheel bike. If holes are noticed clean the area around the hole, wipe dry if wet and use a similar colour tape to the holed plastic as dark and light-coloured plastic will heat and cool at different rates. Avoid patching if the plastic is hot.