A PRACTICAL GUIDE TO TREATING MAIZE SILAGE Maize Silage is being widely used in many dairy and beef rations often contributing over 50% of the forage. It is high in energy in the form of starch, but low in protein compared to grass. These two characteristics encourage a rapid straightforward fermentation once air is excluded. So why should the farmer use a silage additive? The opposite chart, first shown at a Maize Growers Association Conference demonstrates that with a typical maize crop harvested at 30% DM, around 20% of the energy is lost. So for a farmer growing 50 acres, 10 may never be fed. Half of these losses arise from the face/shoulder, due to heating & from what is a ‘fizzy fermentation’. It is proven that use of a chemical preservative or certain bacteria can minimize the face & shoulder losses while use of an inoculate can exercise control over the fermentation.
Maize silage heats up more quickly when it is less well compacted, which is also influenced by maturity and chop length with more mature woody material and longer chopped silage being more difficult to compact. As shown opposite the top half and shoulders are always warmer by at least 10-15 degrees than the bottom of the clamp. Some farmers react to this with their additive application by putting more additive in the top half. This is fairly easy to do since a maize clamp should be filled in long shallow layers from back to front in order to maximize compaction. The other way to reduce heating is to cross the face more quickly.
In Summer aim to cross face in under 3 days In Autumn/Spring 4 days In Winter 6 days
The other reason why maize silage should be treated is to improve stock performance. Treatment of grass silage with inoculant has been shown to improve milk yield by around 1 litre/ cow/day & live weight gain by around 0.75 kg/hd/day. Treating maize silage with bacterial inoculant can produce even larger responses of around 1.5 litres & 1kgm. These high responses which in themselves pay for the product many times over are probably due to the fact that a maize silage clamp, however well it is rolled will always contain significantly more air than a grass clamp. With more air and higher sugars the potential for a less efficient wasteful fermentation is higher, so not only do you lose DM, but the remaining material is less potent.
A Few Practical Tips • • • • • • •
A maize crop will usually yield 15-20 tonnes/acre The clamp must be rolled heavily and consistently Sealing out air is vital, Clamp films are effective (typically in 4 sizes 8*50 m,11*50,16*50, 18*50) Effective and consistent top weight is a must Rubber mats typically 6ft*4ft*16mm With secure covers, use extra sand bags or tyres Don’t forget to use vermin control