Efficient Silage Making
Silage
making relies on anaerobic fermentation to convert sugars to organic acids. An anaerobic fermentation
cannot take place in the presence of air. Where oxygen is present due to poor consolidation, inadequate
sealing or where sheeting is delayed this process is slow, inefficient and wasteful resulting in
high dry matter losses. Often there will be top surface waste, a poorer fermentation in the top third
of the clamp combined with with heating and spoilage on the face. This is especially so when relying
on bacteria naturally present on the crop to carry the fermentation.
Fermentation can only begin when there is no air in the clamp
On the other hand the use of an inoculant together with rapid filling, good consolidation and an effective air tight sealing will generally result in a very fast and efficient fermentation with minimal losses of dry matter. The result being a well fermented silage with minimal waste, more feed value and excellent intake characteristics. A silage inoculant or additive supplies selected elite strains of bacteria which are capable of rapidly fermenting sugars to acids much more efficiently than will take place in an uncontrolled fermentation. This could be likened to running a race with an Olympic athlete set against an 'old codger from down the village'.
Fast fermentation reduces losses, minimises waste and makes better silage
Always use an additive
Dropping the pH to below 5 in a matter of hours deactivates protease enzymes preventing protein breakdown and dramatically reduces the multiplication and activity of a wide range of spoilage organisms including clostridia, yeasts and moulds. With an inoculant, within a day or two the pit will be dropping towards 4 pH and becoming stable. This compares with up to 6 - 8 weeks for untreated clamps. An inoculant will rapidly drop the pH without wasting vast amounts of nutrients on heating the silage clamp for weeks on end. Whether or not an additive is used the fermentation cannot begin until there is no air in the clamp.
Any air in the clamp will delay the fermentation and dramatically increase losses.
Make sure that the clamp really is air tight
It
is not unusual to find silage clamps where the top metre or two of silage is low in quality compared
to the bottom metre of the pit, due to impaired fermentation caused by oxygen presence during the early
part of the fermentation. Often the these top layers are prone to heating on the face and are contaminated
with mycotoxins. Not only will these contaminated layers have reduced feed value and poor intake characteristics
they may cause the TMR or complete diet to heat. This can result in a loss of milk yield of up to 5
litres along with all sorts of knock on effects on cow health and fertility.
Inadequate sealing can represent a massive loss in output and profitability
Keeping Air out of Silage Clamps
The amount of air in the pit depends on a wide range of factors. Firstly dry matter % is obviously
important. Below 25% DM most of the spaces between the particles of silage will be taken by liquid. Above
30% DM unless the clamp is extremely well consolidated air can penetrate up to 1 - 2 metres from the
surface or face with relative ease. Obviously wet, short chopped, leafy material, low in fibre
will consolidate much better than dry, long chopped, stalky material.
Packing density is important. Ruppel, 1992 showed that dry matter losses halved from 20% to 10% when packing density was doubled. That is equivalent to saving 100 tonnes of silage for every 1000 tonnes clamped. More rolling with heavier machines on narrow tyres, rolling no more than 15cms of silage at a time will give the best consolidation. Clamps should never be overfilled. Steep shoulders and slopes of more than 30o are almost impossible to roll. Wetter silage is much heavier than dry silage so putting some direct cut grass on top can be highly beneficial. The faster that filling is completed and the silage sheet goes on the better.
Covering Systems for sealing Silage Clamps
Richard
Webster has looked at hundreds of silage clamps every year for
the past 30 years. it is quite clear that some farms produce silage with virtually no visible
waste and excellent fermentation characteristics year in year out, whilst others make silage which has
top waste and a very average fermentation most of the time. This is probably one of the reasons
why the top 10% of farms have always made double the profit per cow compared with the bottom 10%. Attention
to detail. Basically there is nothing that the best silage makers are doing that can't be done by the
whole industry.
Stating the obvious, oxygen will only stay out of the clamp if there is an impermeable, air tight barrier between the silage and the outside air. If the edges aren't air tight, if there are holes in it, if there are air pockets under it, if there are gaps at the edges, if it is permeable to air then air will get through. On outside pits where the wind constantly changes in pressure much more air will get through.
If the clamp does not have a truly air tight seal, then there will be losses and waste
Both
standard black silage sheets and the new thin clear polythene clamp films which have recently entered
the market are both made of polythene are permeable to oxygen. In fact black plastic sheets have
been shown to be capable of transmitting around 2 litres of oxygen per square
metre per day across the whole sheet and clear polythene cling film sheets around 7 litres of oxygen
/ m2 / day. Even putting several sheets on will allow significant amounts of oxygen into the clamp.
When we consider that average dry matter of grass silage over 30 years has risen from 22% to 32%, we make more dry wholecrops and maize silages, we have more outside clamps, we use far fewer tyres, we have less labour available to do a proper job of sealing the clamp, then it is not surprising that despite the massive technological improvements in silage additives, silage making techniques, machinery, nets, silage covers and gravel bags we still have a major problem with waste and excessive dry matter losses in silage clamps.
Despite massive technological improvements, we still have a major problem with excessive losses in silage clamps
Fortunately there is a cost effective solution. For several years now Richard Webster Nutrition has been promoting a completely new type of sheet. A genuine barrier to oxygen - Silostop Oxygen Barrier Film.
Silostop Silage Covering Systems
Silostop® was developed in Italy by a joint effort between a leading plastic film manufacturer and University scientists.
This was at the request of Italian farmers for assistance from the University for ways to improve their
silage quality and minimise the risk of moulds in the silage entering the food chain. This was particularly
important when producing certain cheeses. Silostop has been scientifically proven by a number of research
centres in the UK, the USA and across Europe.
Silostop Oxygen Barrier Film
The Silostop system consists of a Clear Oxygen Barrier Film along with close weave Silostop anti-UV protective nets and Silostop gravel bags. The Silostop oxygen barrier film is quite different from other clear cling film type sheets available which are made of polythene and which do transmit oxygen. Silostop film is just as effective as cling film type sheets at clinging to the silage surface but unlike other clear films or black plastic sheets does not transmit large amounts of oxygen into the silage surface.
Silostop Clear Top Film is the only silage film which is a genuine Oxygen Barrier
Tests
on Silostop at Michigan State University forage research centre showed dramatic reductions in oxygen
transmission compared with other silage sheets. Silostop oxygen barrier film has proven extremely effective
at reducing or eliminating top waste on grass silage, wholecrop, maize and crimped cereals on commercial
farms. Silostop is the only genuine oxygen barrier film currently on the market and should not be confused
with cheap low density polythene films. Silostop oxygen barrier film has been shown in trials to reduce
dry matter losses in the top layers of silage by 10% - 20%.
Download the Silostop Oxygen Barrier Film brochure and the Silostop Leaflet.
Silostop film is used in the same way as a black plastic sheet to cover the top of the pit and can be protected from UV light either by a new or re-used black plastic sheet or a close weave protective anti-UV net. Since the objective is to exclude oxygen particular attention should be paid to sealing the edges and to protecting the sheet from damage, making sure that all silage sheets, covers and protective nets are secure and well sealed at the edges. Use gravel bags on seams, shoulders and edges and for best results weight the sheets and silage nets with gravel bags, tyres or lorry tyre sidewalls.
Silostop Protective Nets and Gravel Bags
The
Silostop system includes nets and gravel bags. Not essential but highly beneficial especially on outside
pits. Silostop gravel bags are 1 metre in length when filled and weigh around 25kg. They have a much
heavier footprint than tyres and mould to the silage better.
Silostop gravel bags are much more effective than tyres when used against walls, on the ground, along the face and along seams and joins in the sheets. Gravel bags can also be used across the pit at 3 metre intervals as an alternative to tyres.
Silostop anti-UV nets used on top of the clear oxygen barrier film avoid the need to use a black plastic sheet over the clear film. These high quality nets mould well to the silage and do an excellent job of protecting the film from birds, cats, dogs, foxes and accidental damage. Much easier to use than tyres. Silostop protective nets are close weave and are relatively impermeable to wind pressure changes.
Trial work at Leeds University has clearly demonstrated that Silostop nets are much more effective in reducing oxygen transmission into the clamp than open weave, see-through nets and covers. The Silostop close weave net reduced DM losses in the top 30cms of silage due to oxygen transmission from 35% to 8.2% when used on top of two black sheets.
Download the Silostop Protective Net brochure and the Silostop Gravel Bags brochure.
Silostop Anti-UV Protective Nets are much more effective than open weave nets
Silostop
can be used in various combinations with other covering materials either with or without tyres. One of
the best combinations is Oxygen Barrier Film, covered with Silostop Anti-UV Nets with gravel bags round
the edges and
RWN Lorry Tyre Rings to apply
an even weight across the pit. They make the best and most effective silage pit covers dramatically reducing
top waste on silage pits.
As well as being effective on a wide range of ensiled crops Silostop oxygen barrier film is particularly useful for controlling spoilage and top waste on moist feeds as can be seen from the picture here.
A clamp of high quality forage is very valuable. A little additional time and effort in sealing the
clamp together with a little additional investment in additives, sheets, nets and covers can make all
the difference between a below average product with high dry matter losses, poor fermentation, mycotoxins,
spoilage and heating on the face, or a superb, stable, feed with excellent intake characteristics capable of supporting very high levels
of performance and milk yields with less reliance on concentrates. Silostop isn't the cheapest option
but it is highly cost effective compared with the huge benefits.
Use Silostop as a matter of course for superb quality silage
BETTER SILAGE, REDUCED FEED COSTS, MORE MILK AND LESS HASSLE
A More Effective Clamp Sealing System
For advice on making better silage and reducing feed costs, contact Richard Webster.