HAVING put a lot of time and effort into conserving your crop or pasture as silage, what is the value of the crop in the stack or bale?
According to Nutritech International Pty Ltd, it is important to first look at how ensiling works.
When plant material dies, naturally occurring bacteria break down the plant tissue into compost.
Bacteria which break down plant material work best when the environment pH is neutral or slightly acidic (in other words when the pH is seven to 5.5) and there is a good supply of oxygen. When conserving silage, we try to exclude oxygen from the system through compaction and allow a build-up of lactic acid (fermentation), which creates acidic conditions. Acidic conditions discourage bacteria from breaking down the pasture into compost, so by dropping the pH quickly, wastage is reduced. Bio-Sil inoculant enzymes and beneficial bacteria accelerate the pH drop and reduce waste from unnecessary breakdown.
Silage quality can be assessed in two different areas. One is the quality of fermentation, or how well and efficiently the grass has been preserved. Nutritech says good silage making techniques have a big impact here, and using a good silage inoculant, such as Nutritech's Bio-Sil, will help to ensure that the fermentation is fast and efficient.
The other is the nutritional quality, such as energy and protein levels, and this is initially determined by the maturity of the grass crop when it is cut. It is not possible to make silage of high nutritional quality of grass which has gone past its best. However, if a fast, efficient fermentation is achieved, more of the nutrients in the crop will be preserved and there will be less dry matter losses.
One of the best assessors of silage is stock. If the silage is well fermented, it will be more palatable and they will eat it more readily. Stock have been seen to show a marked preference for Bio-Sil treated bales rather than untreated ones because the better fermented bales are more palatable. Stock will reflect the nutritional quality of silage in terms of milk production or growth rates.
Another way of assessing silage quality is to take a sample and get it analysed. It is important to take a good, representative sample. If sampling from a stack face, dig in at least 15cm from the front, and take samples at random across the face. Do not include silage which has started to heat or grow mould. If sampling from a bale, do so straight after the bale has been unwrapped, and dig in well in several places. The silage should be put in a plastic bag and all the air squeezed out. The bag should be sealed carefully and then placed in a second bag to get a double seal. The silage should then be analysed within 24 hours.
If you have trouble translating your silage analysis report when it comes back, Nutritech can supply a Silage Analysis Guideline Sheet which explains the parameters measured and what they mean.