When a factory complex is built, a strategy is always devised to handle its waste or by-products. This can be accomplished in such a way that it can be put to use, or to treat it in such a way that it does not become a nuisance. The same principle should apply when planning and building a pig production unit. Steps should be taken to combat problems associated with waste products. At the same time, the national and provincial health regulations have to be obeyed.
The amount of waste produced by a 100-sow production unit has the same pollution potential as a town with 2 800 inhabitants. A 100-sow unit which markets say 20 piglets per sow per year, will produce about 177,000 kg of undiluted waste per year. Add to this, the above-mentioned waste of washing water, and the total annual waste production of a 100-sow unit could exceed 500,000 kg. The undiluted daily excrement as percentage of the pig’s body weight is on average 7,2%. Therefore, a pig which weighs 60 kg will produce on average 4,3 kg undiluted manure per day. Here are ways in which you can handle pigs waste as a farmer
Handling of solid manure
The handling of solid manure, that is to say manure and bedding, requires a lot of labour. The following are usually needed: Solid concrete floors with a slope; a large enough concrete floor outside the building where the mixture of manure and bedding can be scattered for long-term storage or composting; front-end loaders to transport, mix and turn the manure; and different types of scrapers pulled by a chain or cable, mounted on a tractor.
The solid manure, which is usually mixed with some bedding, can be stacked in wind-rows. It should be constructed and positioned to allow water to drain from the wind-row, without collecting effluent water. Treatment of solid manure, which is being stored for long periods, is essential to avoid stench and flies. The most common method to aerate the material is to regularly turn the wind-row, or to blow air mechanically through the wind-row by means of a centrifugal fan.
Handling of liquid manure
Liquid manure is a combination of all the excreta of the pigs and the water coming from leaking drinking nipples. They also erupt from flushing water for floors and water used for flushing other areas. The handling of liquid manure is preferred for one or more of the following reasons: It is less labour intensive than the handling of solid manure; no bedding material is needed; flies do not breed in liquid manure; slatted floors limit direct contact between animals and their manure; wasted manure water from lagoons can be recycled for cleaning purposes and aerated and odourless liquid manure with a low viscosity can be recycled as flushing water.
Liquid manure can be handled by deep storage channels under slatted floors which are seldom emptied; shallow channels under slatted floor which are regularly flushed clean; open channels which are flushed clean regularly; or wide concrete alleys which are regularly flushed clean.
Slatted floors leave the pens dry and relatively clean and require less labour. Concrete slats are the most common and durable kind, but they also are the heaviest, demanding sturdy support. To avoid contact between the animal and his manure, the feeding places have to be far away from the manure accumulation areas to prevent contamination of what he feed; drinking places must be put over the slatted area because animals tend to urinate while they drink; and partitions that enable animals in adjoining pens to communicate, have to be placed over the slatted area. This is due to the pigs behavior of discharging waste from the body and urinating while communicating.
Expanded metal floors are not recommended because they may damage the feet and nipples of the animals. Untreated aluminium bars are also not recommended because of possible corrosion damage. Wooden slats are not recommended, as they disintegrate, bend and are chewed by pigs.
Deep channel storage systems
The deep manure channel (about 1 m deep) underneath slatted floors serves as a storage tank with a storage capacity of between one and three months. The channel is first filled with water to a depth of about 70 mm to prevent flies from breeding in the initially semi-solid manure. The manure slurry should not be allowed to get deeper than 200 mm underneath the slats. Unnecessary leaking from drinking nipples should be avoided.
When large volumes of slurry is moved, for instance when manure is being dumped, toxic and suffocating gases may be released which can even cause the animals to die. Therefore, the deep channel storage system is not recommended.
Shallow channel and open channel manure removal systems
These systems are very common in piggeries and is recommended for all buildings. There is no build-up of toxic gases or gases with an unpleasant odour. This is because the diluted slurry which is created this way, can be flushed to a tank outside the building. The main disadvantage of flushing open channels and shallow channels is that they require large amounts of water. The amount of fresh water used can, however, be drastically cut by re-using the slurry. It can also be cut by using aerated manure with a low flood resistance as flushing medium.
To conclude, the breeder should remember that control of the environment has become more critical in modern housing, and that serious stock losses can occur if control of the environment is inadequate.