Pig housing should be simple and strong, and should provide shade in summer and warmth in winter. The pig requires a warm, dry bed with the minimum of draughts and changes of temperature, space where it can eat its food, and a separate area where it can dung and urinate. The idea that pigs are dirty animals is not true, and if they are kept in clean conditions they will keep themselves clean. They will dung and urinate away from their sleeping area, and it is a good idea to provide a dunging passage which can be quickly and easily cleaned out each day, without disturbing the pigs in the rest of the pen. Good, well-designed pig housing must take into account the following factors:
- Temperature of the pigs in the house;
- Ventilation of the piggery;
- Space requirements for the pigs, both sleeping and living space and feeding space;
- Access for feeding, inspection of the pigs, and cleaning out the pens; and
- Correct siting of the whole unit and the houses within the unit.
Compared to other farm animals, pigs have very little in the way of a protective coat and rely on their layer of fat to act as insulation and keep them warm in cold weather. Newly born pigs have very little hair and hardly any fat under their skin, so that they are very prone to being chilled which can kill them; they have to be protected from draughts and kept warm. As the pig grows, it lays down fat under the skin which helps to keep it warm, but pigs that are kept under cold conditions will eat more food to provide more energy in the form of heat for their bodies. Pigs are also sensitive to heat, because they do not have any sweat glands and cannot keep themselves cool by perspiring. Pigs kept in high temperatures show an increase in body temperature and a higher respiration rate, which causes them distress and can lead to their death from heatstroke.
OPTIMUM TEMPERATURE FOR PIGS
|Sows||13 – 21°C|
|Farrowing House||15 – 18°C|
|Piglets to 8 weeks old||21 – 26°C|
|Porkers||15 – 21°C|
|Baconers||13 – 18°C|
Square Metres Per Pig
|Sows in yards||3 – 4|
|Weaning in yards||0.7 – 0.9|
|Porkers pen + dunging area||0.73|
|Baconers, pen + dunging area||0.93|
|Gilts and Sows||0.35|
SHADE AND VENTILATION
Shade is important to pigs in Africa, and all buildings should be sited so that they face north-south to avoid too much sunlight penetrating the pens. It has already been mentioned that pigs are prone to heat stress, and white pigs in particular, can suffer from severe sunburn. All pig pens should be at least partly roofed with thatch, iron plastic sheeting.
Very few pigs in Southern Africa are kept in controlled environment housing, and pig pens rely on natural ventilation with a good flow of fresh air through the building. Sleeping areas can be covered with temporary covers made from poles and straw bales during the winter to provide extra warmth.
Figure 1: Pig House Showing Water, Feed and Sleeping Area
Walls and roofs do not require insulation in the Southern and Central African climate but it is most important to insulate the floors of all pig pens against cold and damp. Pigs that have to lie on uninsulated floors can suffer badly from rheumatism, and other conditions of the joints, and can lose the use of their legs. The figure below shows how an insulated floor can be constructed.
Figure 2: A Typical Floor Showing Insulation
The polythene sheeting or roofing felt prevents damp rising up through the floor and the hollow blocks or egg trays provide insulation.
Particular care should be taken with the surface of the floor. A very smooth finish will cause the pigs to slip, and a rough, sharp finish can cause damage to feet, legs and udders. The top layer of concrete should be finished off with a wooden float to achieve the correct surface finish.
Siting the Piggery
When building a new piggery or extending an existing piggery, care should be taken to choose a good site for the buildings, and the following points should be noted:
- The site should not be too cold or exposed to cold winds e.g. winds blowing off a dam in the winter;
- A slight slope will help drainage and the farrowing pens should be at the top of the slope and the fattening pens at the bottom;
- Buildings should not be too close to wells, boreholes or other sources of clean water in case the effluent from the pigs seeps into the water supply;
- Buildings must not be placed under high tension electricity wires;
- Avoid poorly drained and low lying areas which can become waterlogged during the rains;
- Make provision for the drainage of effluent and, if necessary, the storage of manure. Pig manure is a valuable source of soil nutrients and should be ploughed into the land as soon as possible; and
- Buildings should be arranged so that breeding pigs, young pigs and fatteners are separated; this type of layout is shown in the figure below.
Figure 3: Pig House Showing Water, Feed and Sleeping Area
These should be housed in individual pens measuring 3 metres x 3 metres, and leading out into a service area where the boar can serve the sow. As soon as a sow has been weaned, she should be moved into a pen close to the boar pens, so that the boar can signal the fact that the sow is coming on heat.
Figure 4: A Plan of Boar Pens and Service Area
These can be run outside on clean pasture, with small shelters to provide shade and shelter for sleeping, or they can be kept in yards, sow stalls or housed in cubicles.
Are the simplest accommodation for dry sows and they are moved into their quarters after they have been served by the boar. A number of sows can be kept in a sow yard, but it is important that they have individual feeding spaces to avoid bullying and stealing food from each other. Communal feeding can result in some sows getting very little to eat, resulting in their poor condition and the production of very poor litters. Yards should have cement floors and the shaded areas should be littered with straw or stova, so that they can sleep comfortably.
Sow stalls are used in the bigger herds in South Africa and overseas. Each sow has her own stall and is protected from bullying and food stealing by the other pigs. Feeding and management are made easier, and the house can be cleaned out quickly. The house must be warm and free from draughts, and slats at the rear end of each stall keeps the sow clean and free from her own dung. Temperature is important in the house, because the sows cannot huddle together for warmth or move away from direct sunlight.
Figure 5: A Bay of Four Stalls
Cubicles allow for individual feeding and management of the sows but they do allow the sows to have some exercise.
Figure 6: Cubicles Holding Gilts
Good housing for sows from farrowing to weaning is essential, and it is claimed that 20% of all pigs born, die before they reach weaning age. While some of these losses are due to disease and poor nutrition, many little pigs are killed by being squashed by the sow. The most important factor in a farrowing house is to provide protection from the sow for the little pigs. The best way to do this is to use moveable crates for the sow during farrowing and for the first 2 – 3 weeks of the suckling period. The sow is placed in the crate which restricts her movements while the little pigs are free to suckle and move around outside the crate. Additional warmth can be provided for the little pigs by means of infra-red lamps, and creep feed can be given when the pigs are 1 week old.
Figure 7: A Sow Farrowing Down in a Farrowing Crate
Once the little pigs are strong enough to avoid the risk of being squashed by the sow, both sow and piglets can be moved out of the farrowing house and into ‘follow on’ quarters. The P.I.B. recommends a Solari House for this purpose.
Figure 8: A Solari House
Another possibility it to have the follow on pens arranged so that there is a common creep feed area for two litters. This allows the litters to mix and get used to each other, without too much fighting while they are small. When the litters are weaned and moved into the fattening pens they can be graded into equal sizes to avoid bullying.
Some large pig units use the weaner pool system, whereby, the weaner pigs from several litters are moved into a large pen or yard at weaning. It is important to move all the pigs into the pen at the same time, to avoid excessive fighting. The pen or yard must have ample watering and trough space, and a sheltered area where the pigs can sleep. This system has the advantage that pigs can be sorted into batches of equal sizes when they are moved into their fattening quarters.
The pens where the pigs are growing and fattening should be large enough to hold up to 10 pigs with a sleeping area and a dunging area or passage. There should be adequate trough space for the pigs in the pen, and either a water trough or drinking nipple. One of the most common designs, particularly overseas, is the Danish Piggery, shown below.
Figure 9: A Danish Piggery
In Southern Africa pigs can be fattened in comparatively simple buildings because of the kinder climate. A boy type sleeping area that can be covered during the winter and the covering removed in the Summer is the main requirement. The whole of the sleeping and feeding area can be roofed with thatch or zinc sheets, and the dunging passage does not need to be covered.
Figure 10: Example of Simple Pig Housing