Silage production is fermented, high-moisture stored fodder which can be fed to cattle, sheep and other such ruminants (cud-chewing animals)] or used as a biofuel feedstock for anaerobic digesters. It is fermented and stored in a process called ensilage, ensiling or silaging, and is usually made from grass crops, including maize, sorghum or other cereals, using the entire green plant (not just the grain). Silage can be made from many field crops, and special terms may be used depending on type: oatlage for oats, haylage for alfalfa; but see below for the different British use of the term haylage.
It is an important way farmers use to feed cows, goats and sheep during periods when pasture isn’t good, such as dry seasons.
Silage assists farmers store forage (pasture) for up to 2yrs while maintaining their full nutrients.
Silage production; Steps in Silage Making:
Silage production; Shallow Pit:
Prepare a shallow pit, preferably on slightly sloping ground. The depth of the pit should decrease from the higher side of the sloping ground to the lower side giving a wedge-like shape. Dimensions of the pit depend on the amount of forage to be stored.
As a rule of thumb 72 cubic feet (2 cubic metres) holds 1000 kg (or 20 bags) of fresh, chopped material. This requires 2030 litres of molasses and 10 metres of polythene sheeting.
Silage production; Harvest:
This is the second step in silage making here the forage e.g maize is harvested from the field. A rule of thumb for harvesting forage is, the more mature a crop is, the lower the nutrients it possesses. This is because as the crop matures, it has less leafy content and more “harder ” parts such as a stronger stem resulting in lower nutrients and hence it is important that a farmer harvests the crop at the right time. The fiber content increases with maturity and it is unsuitable as it has lower palatability (so a farmer is likely to witness lower intake by the cows), less digestible and has a lower protein content level.
Silage production; Wilting:
Wilting Is the process of making the crops loose some moisture. This can be done by laying the plants against the wall or on a rack outdoors and in the sun. When wilting, it is important to remember not to wilt in thick layers as the plants in the bottom will not be exposed to the sun/heat and may lead to decomposition undoing the silage making process. Turning severally is also advised.
Silage production; Chopping:
The crops should then be chopped to lengths of between 1cm-3cm for several reasons:
• Having shorter chop lengths allows for better silage making. This is because longer chop lengths are more difficult to compress and displace the air within the crop especially the stems which are harder.
• Livestock especially young ones consume more with shorter length forages as compared to longer ones and more consumption of good quality forages usually results in higher milk production.
• Chopping grass can lead to more efficient silage fermentation. It allows sap, containing
sugars, to be released.
• A chopped material will also break down more rapidly in the rumen and lead to higher animal intakes. It is also said to more palatable, because it ferments more quickly.
• A short chop can allow faster harvesting because more the amount or weight which fits in a trailer is increased
Silage production; Add Fermentable Substrate and compact:
Spread polythene sheets over the sides and floor of the pit so that the forage does not come into contact with soil.
This stage is carried out differently by different farmers. There are those that prefer spreading molasses on the chopped crop as they compact it while others prefer to compact as it is. Especially in maize silage where farmers ensile their maize without molasses and opt to utilize the natural sugars in the maize plant.
Whichever way you take, compacting must be done well and thoroughly.
This can be done in plastic tubes, a silage pit or above ground. What you are trying to achieve is to expel as much air as possible and to maintain the condition as is without allowing air in.
Press the forage down with your feet or a suitable weight (e.g. a drum full of water) to force out as much air as possible. This will prevent fungi attacking and destroying the forage.
Add another bag of the chopped feed, sprinkle diluted molasses and compact the forage again. Repeat this process of adding forage, diluted molasses and compacting until the pit filled in a doom shape.
Cover the pit after a final pressing with polythene sheeting to prevent water seeping into the silage and dig a small trench around the sides of the pit.
Then, cover the pit with soil: a layer of 24 inches (in the case of wet, fresh fodder) up to 36 inches (in the case of more dry forage) of soil to keep the air out and to prevent damage of the polythene by rain, birds and rodents.
The conservation of the material by microorganisms takes a couple of weeks. Thereafter, it can be fed, but you better leave it until a time of feed shortage. With good sheeting and enough soil on it, the silage can be kept well for 1 – 2 years.
Open the pit from the lower side of the slope. Remove enough material for one day’s feeding, and then cover the open end again.
