चारे के लिए उत्तम गुणवत्ता की पुआल और सिलेज बनानें का तरीका
Grass is the cheapest source of feed for any livestock enterprise and effective utilisation of grass and its management is the key to getting the most of your grassland. Ruminant animals depend on grass as a major source of energy and protein as well as vitamins and minerals. So to take maximum return from the grass there is a way to make qualitied hay and silage from these.
Silage contains 1%-5% of free sugar. This can be fermented anaerobically into a lactic fermentation that will remain stable for years or even decades. Ideally grass should be cut, allowed to dry a little to 75% moisture content, and then chopped and taken to the store (silo) and compacted and sheeted with polythene sheet to exclude air. Silage has a characteristic and pleasant smell.
Haylage usually has a moisture content of 75% to 55%.
Hay is grass that is cut, dried and stored by humans to be used at a later date i.e hay is sun-dried grass whiles silage is fermented pasture (grass). Hay making is the process of turning green, perishable forage into a product that can be safely stored and easily transported without danger of spoilage, while keeping nutrient loss to a minimum. This involves reducing its moisture content by drying the forage in the sun. The process of drying the green crop without significant change in aroma, flavour and nutritive quality of forage is called "curing". This involves reducing the moisture content of green forages, so that they can be stored without spoilage or further nutrient loss. Feeding hay to livestock helps reduce the amount of concentrate feeding, and thereby, the cost of feeding. The low moisture content of hay considerably reduces cost.
Objective of making hay and silage
The objective behind making hay and silage is to preserve forage resources for the dry season (hot countries) or for winter (temperate countries) in order to ensure continuous regular feed for livestock, either to sustain growth, fattening or milk production, or to continue production in difficult periods when market prices are highest.
Suitable crops for making hay
Crops with thin stems and more leaves are better suited for haymaking as they dry faster than those with thick, pity stem and small leaves. These may include Oats, Desmodium, Lucerne, Maize, Sorghum, Napier grass, Rhodes grass. Leguminous fodder crops (e.g. Cow pea, Lucerne, etc) should be harvested at the flower initiation stage or when crown buds start to grow. Grasses and similar fodder crops should be harvested at the pre-flowering stage. At this stage, the crop has maximum nutrients and green matter. After flowering and seeding, grasses contain fewer nutrients. In order to make the process of curing easier, the fodder should preferably be harvested when air humidity is low.
Basic method of making hay
- Forage is cut before it is fully mature (long before it has seeded), to maximize its nutritive value. Although cutting hay early will result in lower total volume, the increase in nutritive value will more than compensate for reduced yields.
- Leaves are more nutritious than the stems, and so when cutting forage, it is important that it is cut with as much leaf and as little stem as possible.
- Do not leave cut forage to dry in a moist environment, as this will encourage the growth of moulds. These can be extremely harmful to livestock and to people handling it.
- The cut forage is laid out in the sun in as thin a layer as possible, and raked a few times and turned regularly to hasten drying.
- Chopping forage into small pieces after drying will hasten the dying process.
- The drying process may take between 2 to 3 days.
- Hay should not be over dried as it may start to ferment and also become a fire hazard.
- The dried hay should ideally be stored in form of bales when the moisture content is low, ideally less than 15%. This helps storage and requires less space.
Leaves are more nutritious than the stems, and so when cutting forage, it is important that it is cut with as much leaf and as little stem as possible. However, during drying, the leaf (being more brittle) will tend to shatter. Hay should therefore be handled with care, to try and minimize the amount of leaf that is lost in this way.
Crops with thick and juicy stems can be dried after chaffing to speed up the drying process and to prevent loss of nutrients. Field curing is conducted during bright sunny weather but may result in bleaching of the forage and loss of leaves due to shattering. To avoid this, drying can be done in barns by passing hot air through the forage. Although artificial drying produces hay of good quality, it is expensive and beyond the reach of small and marginal farmer but can be attempted on a community basis in areas where there is a need, and the necessary facilities.
Storage of hay
- Hay must be stored in a dry environment.
- Hay can be baled and stored under cover or can also be stored by creating hay stacks. Stacks may be covered by plastic sheets to keep out rain and prevent from exposure to excessive sun.
Problems with hay making
- If hay is dried in a moist environment, for example during heavy rains season, mould may grow on the hay. These moulds can be extremely toxic to animals as well as the people handling it.
- In such cases it is advisable to wait till the end of the rainy season before cutting the forage. This may lead to lower nutritional content in the hay, but this is better than toxic hay. The resultant may be supplemented with other feeds.
- On the other hand, drying the hay too fast may lead to shattering of the delicate parts of the plant, causing a subsequent loss of nutrients.
- To avoid this, drying can be done in barns by passing hot air through the forage. Although artificial drying produces hay of good quality, it is expensive, but can be attempted on a community basis in areas where there is a need, and the necessary facilities. (NR International,Livestock Production Programme
In short for hay “the crop is cut and then repeatedly spread during the day and rowed up at night until the moisture content is reduced to under 15%, and preferably near 10%. It is then baled and carted to the stack. A thin stemmy crop can be turned into hay in 48 hours under hot conditions, but a thick leafy crop can take weeks.”
Silage-making is a fermentation process aimed at preserving forage in its wet state away from air. One is seeking to lose minimum dry matter and nutritional value and to avoid creating products toxic to the animal. Good silage is light brown in colour, has a sharp taste and little smell as its lactic acid content is right. It is very stable and can be kept for years if required
To obtain good silage, it is necessary to:
- Use airtight silos (total anaerobiosis); several types of silo are used around the world:
- tunnel silo, trench silo, corridor silo, tower silo, etc.,
- collect forage which is not earth-soiled, chopped and then piled up,
- If necessary apply additional techniques such as pre-tedding for forage with high water content, or use of preservatives (sugar products, formic acid, anti-moulds, etc.) to improve preservation.
- It is essential to harvest forage at the best time, from the point of view of nutritional quality, quantity available and climatic conditions, and then to store it properly to reduce losses.
Additives are available to help maximise the quality of silage produced. There are three main types of additives:
- Sugars/carbohydrates – by adding extra sugar or molasses the crop is more able to produce lactic acid. Some additives contain materials to stimulate the lactobacilli bacteria.
- Acids – formic and sulphuric acid are applied at a rate of between 3–5 litres per tonne as the grass is picked up in the field. This reduces the quantity of lactic acid needed to reach a stable pH.
- Preservatives – these suppress chemical reactions and allow the fermentation process more easily. These are usually within acid additives.
Round bale silage is a relatively new method of preserving forage. It is a very flexible system because of its low capital costs. It is a combination of hay and silage making and has certain advantages and disadvantages over other forage preservation systems. Round bale silage is simply forage of a relatively high moisture content that is baled with a round baler and then stored in a sealed container, usually a plastic bag. Both grasses and legumes can be preserved as round bale silage if proper techniques are followed. It is much easier to make good hay crop silage in silos than in large round bales.
Round bale silage has three distinct advantages over haymaking or conventional silage making:
- Harvesting forage as round bale silage has the potential of minimizing harvest losses.
- Round bale silage requires a relatively low initial investment of capital.
- Round bale silage also is an extremely flexible system.
O/o Dy. Director of Agriculture, Raipur