The maize seeds are compacted and usually added to the silage, and the straw can be used for bedding.
To ensile maize it is important to keep the chop length short, about 1 – 2cm but no less as the maize would otherwise lose the effect of its fibre values. A very short chop length may also lead to rumen infection. Where clamp facilities are good and there is a requirement for more fibre in the diet, chop length should be closer to 2cm. At this chop length, the vast majority of kernels will be cracked which means that the crop will have a higher digestibility when fed. This is an added bonus. The length of chop in the field varies depending on the sharpness of the harvester knives and its forward speed through the crop.
Clamping well and consolidating properly are important. The pit should be covered and sealed carefully. A pit that is open at both ends makes rolling and filling a lot easier.
The density of maize silage is roughly half a tonne (500kg) per cubic metre. For every hectare of maize silage grown, and assuming a yield of 40 tonnes of silage per hectare, 80 cubic metres of silo space will be needed.
Since maize has a very high dry matter content almost no silage effluent is produced. The leaves are very valuable at ensiling as they are rich in sugars and so help to preserve the crop.
During ensiling, the anaerobic bacteria use about 95% of the sugar in maize and energy is lost during their conversion to organic acids. Therefore, very little of the energy in maize silage comes from sugar. Since starch is not used up in the process of silage making, it represents 50% of the available energy of maize silage.
For exact details on what happens during ensiling see ‘The Chemistry of Silage’ section in the Silage Project.
Maize Silage Close-Up