Most are a bit confused by the question thinking they are pretty much the same thing — but they are actually poles apart.
The key to making good silage is to start with an excellent fodder source.
The reality is the quality of silage is always a step in grade down from the crop you start with, and it matters not whether it’s pasture, maize, cereal or lucerne.
Two factors contribute to this — the fermentation process and the inability of the animal to select when fed back.
Our first mistake in making excellent silage is in chasing yield as, with the exception of maize and lucerne, yield always comes at the expense of quality.
The second mistake is in not understanding well enough what happens during the ensiling process.
We don’t all need to be experts in silage making here, but it helps to understand the most important factors and how they impact the end result.
The shorter the period between initiating the ensiling process (which starts at cutting) to when the pH reaches its magic number — 4.2 (but it ranges from 3.7 to 4.7, depending on the crop and conditions) — the better.
It is the soluble carbohydrate to soluble protein ratios that largely determines this because this ratio determines the buffering capacity of the crop.
In short, soluble carbohydrate is the source of acid, and soluble protein is the buffer.
The lower the sugars and higher the protein, the greater the buffering capacity which, in turn, slows the rate at which the crop hits the magic pH. And, the longer this period, the more nutrient is lost from your silage.
This is why maize is the easiest crop from which to make silage well, and pure legumes the most difficult. It is also why silage crops should always be cut mid-afternoon as sugars are at peak and NPN at its (relative) lowest.
The importance of wilting to a DM of 35 to 40 per cent cannot be overemphasised to optimise the balance between compaction and avoiding seepage (in which all the goodies are lost), and compaction to eliminate oxygen.
Too dry and we cannot sufficiently compact the crop; too wet and we get seepage.
Both increase the lag between ensiling and obtaining our target pH 4.2.
The past couple of decades have seen a massive improvement in method and repeatability of successfully making silage well — most of this is around inoculant use. But now there are so many it is difficult to choose which one you should use.
The newest is 4SIGHT’s enSILE-Bio RTU, a ready-to-use catalyst that accelerates the growth of the endogenous (not applied) lactic acid bacteria — the ones already contaminating the silage in vast numbers.
This means the carbs are converted to acid much sooner and finishing the process faster resulting in better quality silage.
The reports coming back from early adopters are that “the silage looks exactly like the feed that went in”. Music to my ears.
– Dr Les Sandles
4Sight is an Australian business focused on equipping agriculturalists with innovative and cost-effective solutions for regenerative farming practices and sustainability.