Silage is one of the feeds you can give your animals to maintain good health and high milk production.
When making it, one uses the principle of fermentation under anaerobic conditions to prevent fresh fodder from decomposing, allowing it to keep its nutrient qualities thus preserving feeds for your dairy cows in periods of scarcity.
Silage is simple to make, with key components being sufficient chopped fresh fodder, additives to boost organic acid production and a plastic lined trench or pit while keeping in mind the distribution and packaging of the crop in the pit (about 15cm per layer) and you must expel as much air as possible. The rate of distribution and packing affects the rapidity with which the air is eliminated.
However, several fodder factors affect the type of fermentation, extent of the losses during ensiling, and the quality of the silage produced.
They include the stage of maturity at harvest and chemical composition of the fodder, amount of soluble carbohydrates or sugars they produce, fodder moisture content (normally 60 to 70 per cent or 30 to 35 per cent dry matter), the length of cut to use (about an inch) to help expel trapped air when trampled and pH (below 4.2 for wet forage and below 4.8 for wilted forage).
Wilt too wet fodder with more than 70 per cent water in the sun taking care not to dry too much to result in molding. One or two hours may be sufficient on a good sunny day or half day to a day on very humid days.
If wilting is not possible due to unfavourable weather, add 5 to 15 per cent dry hay and chop them together. You can use maize, sorghum, oats, pearl millet or napier grass depending on ease of availability.
They should be harvested when the yield of total digestible nutrients is high, for example harvest maize or sorghum when the seeds are soft but not milky when squeezed open.
Most grasses should be cut after emergence of their heads but before they start blooming.
Napier grass is cut about a metre high. Legumes like desmodium, lucerne, calliandra, sweet potato vines and groundnuts leaves should have young pods which are not dry. Their seeds can be bought from agrovets, Kenya Seed Company or International Centre for Research in Agroforestry. The additives are molasses, formic acid, lime, urea or simply sugarcane chops.
The forages contain fermentable carbohydrates or sugars necessary for bacteria to produce sufficient organic acids that act as preservatives. The top of the heap should be thoroughly tramped and covered well with the plastic lining material to prevent rain from entering or rodents interfering.
Even though yeasts secrete enzymes, which break down the complex fodder parts into simple sugars, their concentrations are considered undesirable. Yeast will cause heating of silage and energy losses when exposed to air during feeding. They ferment sugars and degrade desired lactic acid to ethanol, carbon dioxide and water.
Ethanol decreases the amount of sugar available for fermentation giving milk a bad taste. Yeast will also cause a rise in silage PH to trigger the growth of more spoilage organisms such as molds that are harmful to the cow.
It takes about 30 to 40 days for the silage to mature and be ready for feeding. Spoilt silage means poor fermentation and has offensive taste, strong smell and slimy soft texture when rubbed from the fibre.
With correct components of silage, and following the proper preparation procedure, a desirable fermentation process will go on smoothly minimising nutrient seepage while giving very nutritious, palatable, digestible and laxative silage, which when fed to your stock, the ultimate result is happy cows for a happy farmer.