Introduction to “How To Make Silage for Dairy Cattles”
The following information is about “How To Make Silage For Dairy Cattles”.
The product obtained by fermenting any green plant material in the absence of air is called as Silage. The process of Silage does two things: first it ferments the sugars to form acids and then breaks down the forage proteins into simpler compounds. The entire process of making the Silage is called ensiling and takes almost 2 or 3 months for the fermentation to occur. The container where the Silage is stored is called silo. Conserving the green fodder through the process of Silage is proved to be an economical way of dairy farming. Silage once prepared can be stored for almost 2 years and it should be noted that good quality Silage doesn’t contain butyric acid. When Silage is not produced under hygienic conditions, then the Silage obtained after the process is expected to contain butyric acid content.
Crops that are considered for Silage making are maize, sorghum, oats, pearl millet, hybrid Napier etc. The quality of Silage obtained from these crops can be improved by adding molasses, urea, formic acid etc.
Advantages of Silage
Some advantages of Silage making are:
- Crops can be ensiled into hay or dry fodder when the weather doesn’t support curing.
- When there is availability of Silage, large unit of cattle can be raised on the farm land.
- Some varieties of weed crops are used to produce Silage. This process can kill many weed seeds.
- Silage from the green plants contains 230 kgs of dry matter/m³ when compared to hay that contains 66 kgs/m³ of dry matter.
- Forage crops that are stem like in nature when converted into Silage get better utilized by the stock.
- Unwanted things present in the fresh crops get eliminated after ensiling.
- It can be stored in pits for many months.
- The ensiling process is a fermentation process that makes the Silage taste better than green grass and hence is suitable for cattle.
Characteristics of Silage
The ensiling process defines the quality of the Silage produced, its nutrient loss and relative palatability.
- The colour of good Silage should be yellowish green in colour. Excessive heating may cause dark brown or charred black colour material in the Silage. Too much moisture in the Silage appears to be deep green to black in colour.
- The odour of good Silage should not be very strong and objectionable. If the Silage smells musty or has strong butyric acid ammonia odour then it indicates that the Silage has lost its feed value.
- High moisture content, i.e. more than 75% indicates that the Silage has less feed value per kilogram. This low content of feed value is due to seepage.
- The chemical composition of the Silage is estimated on the type of crop, ensiling process and compaction. The pH of the Silage determines its quality and should be always less than 4.2. The general recommended values of butyric acid and ammonical nitrogen should be less that 0.2% and 11% respectively.
- Proper management and care can help produce good quality Silage. The Silage is generally classified into 3 categories: grade 1 (crude protein >15%, prepared from young grass and legumes), grade II (crude protein content in between 10 to 12%, prepared from cereal and legume grasses at emerging stage) and grade III (crude protein content <10%, prepared from grasses of maize and sorghum at seeding stage).
Prerequisites for making the Silage
- Harvesting the crop should never be done during the rainy season in Silage making.
- Before preparing the Silage, the unit size of the farm should be properly assessed and the pits for silos should be created accordingly to store the feed during the lean months.
- The silo in which the Silage is prepared or stored should have walls that prevent the entrance of air and doors that fit snugly. Flow of air into the Silage will spoil the Silage.
- The crop that is being used for making Silage should neither be too dry nor too wet. The stem of the crop should be solid with minimum air in the mass. Hollow stems should be crushed before use.
- The grass is pre wilted for a few hours before ensiling. The moisture content should be less than 70-75%. This helps in the butyric acid type of fermentation.
- The crop that is being used for preparing the Silage should be chopped into smaller pieces if needed. The shorter length of the material facilitates immediate bacterial fermentation and produces acid very rapidly. The minimum size of the chopped pieces should be 4 to 5 cm in length.
- Decide on the proper ratio of ingredients to make the Silage.
- Add some extra things like salt, molasses, etc. to improve the quality of the mixture.
- The silo should be filled properly with the required material and distributed uniformly throughout the silo.
- The silo should be covered with materials like straw, saw dust etc.
- Intermediate checks should be done to check the seal of the silo flatten the material and seal any cracks if any.
- The type and material of the silo container also have great importance because it determines the quality of the final product.
Pit preparation and materials for making Silage
Silage is also known as the pickle of green fodder and is considered to be easily digestible. The best quality Silage is prepared from cereal fodder crops like maize, sorghum, pearl millet, Oats and barley, etc. because they are rich in carbohydrate or sugar content. The green grass should be harvested at milking to dough formation stage, especially when the moisture is around 65 to 70%. The fodder is chaffed to the size of 1 to 2 inches and then filled into the pit.
A Silage pit has to be created with the required dimensions. The recommended dimensions of a pit are 1 x 1 x 1 m so as to store 500 kgs of Silage. The Silage has to be located in an area where there is no water logging problem. The pit has to be surrounded by thick plastic on all sides or it can be constructed with bricks and cement.
The fermentation mixture estimate for 1 ton of Silage needs the following materials:
- 1 kg jaggery or molasses
- 1 kg of salt
- 1 kg of mineral mixture
- 1 kg of di calcium phosphate
- Lactic acid bacteria
- 1 kg of urea
Silage making procedure
Mix all the above mentioned ingredients in a drum and add water to it. Small pieces of fodder (chaffed) are also added to the fermentation mixture in small quantities and pressed hard to remove the air from the mixture. Removing the air is very important. Pressing is done manually in small silos, but for large silos pressing is done by tractors. The pit is sealed and wrapped with a plastic sheet compactly and 5 inches thick, moist soil should also be used to cover the pit. Heavy stones are placed on the top of the pit so that air comes out of the pit. The pit should be covered properly such that water doesn’t enter the pit.
The pit can be re-opened after 15 days or when needed. The Silage is ready to be fed to the cattle after 45 days. The colour of Silage should be golden yellow. All the fungus formation on the top of the Silage is removed from the top layer before usage. During the initial stages, feeding Silage should be restricted to a minimum of 5 to 10 kg per animal each day so that the animals adjust to the feed slowly.
Types of silo and other containers
The silo has to be located very near to the crop that is being used for ensiling. The different types of silos are:
- Stacks
- Clamp silo
- Pit silo
- Trench silo
- Tower silo
- Temporary and portable silo
Problems of Silage making in India
The silage making process is not very common practice in the tropical regions because of the following reasons:
- The low density of the Silage; hence needs the process of excluding air from the ensiling process.
- Stable Silage is produced without additives.
- The largest amount of molasses is required for improving the quality of the Silage.
- Growth of mould on pre -wilting grass is a common problem in tropical regions.
- The grass in the tropical region has low feeding value and ensiling can reduce the value further.
- The Silage made from the tropical grass has no improvement on the weight of the cattle during the winter or dry season. Therefore, tropical grass Silage has to be fed along with another concentrate feeds for obtaining good milk production.
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