By Ken Stroud,
Volac NI forage specialist
PEOPLE grow maize to maximise their milk margins from forage as this ‘rocket fuel for dairy cows’ makes an ideal partner with grass silage.
Yet after all the expense and effort put into growing maize, take care as it heads for the silage pit. Bacteria, yeasts and moulds can be present in your crop when it is ensilaged and affect dry matter, DM, content and nutritional value.
As well as fungal diseases that can live on maize, for example Eyespot, Smut and Fusarium, remember that decomposing crop debris and dirt can become trapped in leaf joints. Plus if the crop is harvested after it has started senescing (fading away), then dead tissue is a breeding ground for undesirable bugs.
These are in addition to any soil microbes that get into the stem base, especially in muddy conditions. One would not make grass silage from almost dead grass in muddy fields so what can be done when ensiling maize in these conditions?
The rapid response is two fold. Minimise the number of harmful bugs getting into the clamp from the field and then inhibit the growth of any that do make it into the silo.
Make sure the area around your silage pit and your machines are completely soil free. Clean and tidy always pays off. Also do harvest at the right time and at the right height.
Today’s maize varieties often reach the desired 30 to 33 per cent DM for harvest while still green. Hence no need to wait for them to die back.
And remember, as well as the stem base tending to carry soil and mould spores, it is of low feeding value. So leave at least 15cm of stubble.
Then to curtail the growth of any harmful bugs that get into your clamp an Ecosyl dual active additive from Volac is needed to help improve fermentation so that pH falls faster and undesirable bacteria are inhibited. This additive also curtails yeasts and moulds that cause heating. This is important, as heating is a sure sign that some of the time and money you put into growing that maize is about to go to waste!
Then consolidate the clamp thoroughly and seal with great attention to detail. Time that will be very well spent.
Maize needs compacted to a density of 700g of fresh weight per cubic metre. To improve consolidation have a chop length of 1.5 to 2cm and fill clamps in horizontal layers no more than 15cm deep and not in a wedge shape. Then seal with an oxygen barrier film on top, use side sheets folded over using at least one to two metre overlaps, followed by a top sheet pulled tight, a well weighted down woven sheet and finally netting to stop birds damaging the covers and letting air in.