Housing for a Small Scale Pig Unit
Contents - Previous - Next
For units with 2 to 15 sows, specialized buildings for the various stages of production may not be practical or desirable. For the smallest units of 2 to 6 sows a kind of universal pen which is about 2.7m wide and 2.8-3.0m deep (including feed through) which can be used for:
I sow and her litter, or
2 litter of weaned piglets, or
3 to 4 gestating sows, or
9 growing/finishing pigs of up to 90 kg live weight, or
This type of pen shown in Figure 10.28, provides a high degree of flexibility but usually does not allow as efficient a use of the building space as the more specialized pens.
When used for farrowing, the pen should be adapted with guard rails 25cm above floor level and 25 from the wall to protect the piglets from being crushed as shown in Figure 10.28b. However, confinement farrowing is one of the most efficient ways of reducing piglet losses. An arrangement with fixed or removable rails, which divide the pen, as shown in Figure 10.28c, will offer some degree of confinement.
In some climates it may be desirable to give sows with litter access to exercise yards. However, for the relatively short suckling period (6 to 8 weeks), it is usually considered best to keep the sows confined in pens with their litters.
A creep for the piglets is arranged in one corner of the pen. It is recommended that a temporary ceiling (e.g. wire netting covered with straw) 50 to 60cm above the floor in the creep area be constructed to prevent draughts and to keep warmer temperatures for the piglets during their first weeks of life. Where electricity is available, heating with an infra-red lamp may be used instead. Piglets are fed in the creep area out of reach of the sow.
Figure 10.29 shows a single row pig unit for 2 sows and fattening pigs, and Figure 10.30 a double row pig unit for 4 sows having a central feeding alley. The semi-covered manure alleys are arranged along the outside walls separated from the resting area of the pen. This arrangement will allow rain water to help flush away the waste to the drain channel and on to the manure store which has to have extra capacity for this water. However, in the 4 sow unit the furrowing pens have fully covered manure alleys for increased protection of the piglets.
The roof may be equipped with gutters so that rain water can be drained away separately or be collected for use as drinking water for the pigs.
A single tubular steel or round timber rail 20cm above the outside, rear wall (1m high) is desirable to increase security without interfering with ventilation.
Both buildings shown in Figures 10.29 and 10.30 can be extended to accommodate 2 to 4 more sows by adding 2 pens for fattening pigs at one end every time a farrowing pen is added at the other end.
Table 10. 10 Minimum Trough Length and Height of Partitions in Various Types of Pig Pens
|Minimum trough length||Minimum height of pen partitions|
|Sow in farrowing pen||0.7||1.0|
|Loose dry sows in pens||0.5||1.0|
|Stall for dry sows||0.5||1.0|
|Piglets||10 kg||0.14 - 0.15||0.6|
|Piglets||15 kg||0.16 - 0.17||0.7|
|Pigs||25 kg||0.18- 0.20||0.8|
|Pigs||40 kg||0.22 - 0.24||0.9|
|Pigs||60 kg||0.25 - 0.27||0.9|
|Pigs||90 kg||0.30 - 0.32||0.9|
|Pigs||120 kg||0.35 - 0.37||1.0|
Figure 10.28 Universal pen.
Figure 10.29 Single row pig unit for 2 sows and fatteners.
Figure 10.30 Double row pig unit for 4 sows and fatteners.
Housing for the Medium Scale Pig Unit
In pig units for more than six to eight sows it becomes feasible to construct specialised pens for the various production stages, but these can still be accommodated under the same roof. A larger production volume can be accommodated by extending the unit shown in Figure 10.31 up to about 15 sows. A further increase should then be accomplished by building an additional separate unit of this type with up to 15 sows, as too many animals in one building is a potential health hazard.
Housing for the Large Scale Pig Unit
In large scale units special provisions must be made for efficient health control. This means: not too many animals in one building; animals of approximately the same age housed together; using an all-in-all-out system with thorough cleaning and disinfection of every house between each batch of pigs; placing the buildings 15 to 20m apart and surrounding the entire site with a secure fence.
Specialised pens in separate houses for the various stages in the production is normally feasible in units for more than 20 to 30 sows. Each type of pen can be designed with dimensions for the most efficient use of the building space, as they don't have to fit in a layout with other types.
The type of farrowing pen shown in Figure 10.32 offers a relatively high degree of confinement in that the sow is restrained in a farrowing crate during farrowing. Five to ten days after farrowing the crate is removed or opened, to free the sow, as indicated in the figure. A slightly askew arrangement of the farrowing crate will allow for a longer trough for the piglets in the front of the pen, but is more complicated to construct.
A reduction in space requirement can be accomplished by putting the sow in a farrowing pen, consisting merely of a farrowing crate with 0.5 and l.0m wide creep areas on either side, one week prior to farrowing. Two weeks after farrowing the sow and piglets must be transferred to a suckling pen equipped like the pen shown in Figure 10.28b but with the dimensions 2.3m wide, by 2.35m deep and with a 1.4m wide manure alley.
Figure 10.31 Pig unit for 10 sows and fatteners.
Figure 10.32 Farrowing pens with crates for confinement of the sow during birth.
Housing for Growing/Finishing Pigs
Growing/Finishing pens 2.8m wide by 1.9 to 2.2m deep and with a 1.2m manure alley can accommodate the following number of pigs, according to their weight:
up to 40 kg - 12 pigs
40 - 90 kg - 9 pigs
over 90 kg - 7 pigs
Where it is very hot it is preferable to reduce the number of pigs per pen below the numbers given here. The manure alley must be well drained, preferably by a covered drain, but an open drain will also serve provided that it is outside of the pen to prevent urine from flowing from one pen to another. Bedding in the pens is preferable for the animals' comfort and to reduce stress, as the bedding will provide them with something to do. Controlled feeding is important to ensure the best possible feed conversion.
Housing for Gestating Sows
Gestating sows are usually the last group in a pig herd to be considered for confinement housing. However, there are obvious advantages which could have a great influence on the production efficiency when sows are confined and controlled during gestation.
As their litters are weaned, sows can be returned to the gestating sow structure and placed in one of the pens arranged on either side of the boar pens for easy management of sows in heat. After mating and the three week control period, the sows should be re-grouped according to the actual farrowing dates.
The type of accommodation shown in Figure 10.33a will always have four sows per group as the gates in the manure alley are used to enclose the sows in their stalls while cleaning the pen. The stalls, which are used for both feeding and resting, should be 0.60 to 0.75m wide, depending on size of the sows.
With the type shown in Figure 10.33b, the numbers in the groups can vary according to the size of the herd and farrowing pattern, but sows in one group should be in about the same farrowing period (within about 10 to 15 days of each other).
The feeding stalls should be 50cm wide, and a bar should be installed which can be lowered after all the sows have entered the stalls. This arrangement will prevent sows from backing out of their assigned stall, and biting and stealing feed from other sows. When all the sows have finished eating, the bar is lifted and they can leave the feeding stalls.
Behind the feeding stalls there is a manure alley with gates across and which can close the opening of the resting area in order to confine the sow while cleaning out the manure alley. The width of the manure alley can be increased from 1.5 to 2.5m if desired, so that cleaning out can be earned out by a tractor mounted scraper.
In both types of pens, exercise yards when considered feasible, can be arranged behind the building.
Figure 10.33a Groups of four sows in resting and feeding stalls and with access to a manure alley.
Figure 10.33b Groups of five sows with access to feeding stalls and a headed resting area, where they are enclosed during cleaning.
Figure 10.34 Layout of a 50 sow unit.
Special Arrangements for Warm Climates
Many of the principles that have been discussed above apply equally well to both hot and temperate climates and are basic requirements for the housing of pigs. The open type of confinement system has its limitations, but applied in many warm areas leads to a major improvement in production.
The complete control of the environment in animal houses is generally far too expensive to be feasible, in particular when considered in connection with nonconfined systems. However, provisions for shade, proper roof colour and material and controlled air movements, which have already been discussed, can be both practical and economic.
A spray or a wallow can considerably reduce heat stress in pigs. A wallow can be anything from a water filled hole in the earth to a concrete trough. While wallows are effective and need not be expensive, they tend to become unsanitary if not regularly cleaned.
From a hygienic point of view sprinklers which spray water on to the pigs, are preferable, but water consumption can be up to four times as high as for a wallow. Water consumption is about 20 litres per pig per day for 10 hours continuous spraying, compared with 5 litres per pig per day using a wallow. However, a spray system can be operated intermittently by a timer which can limit use to about 2 litres per pig per day. The spray should be directed on to the pigs and not into the air. The spray system can be effectively used with all categories of pigs, except very young piglets. A sprinkler in the manure alley of the farrowing pen, operated from the time the litter is about two weeks old, may help the sow to maintain her feed intake. Hosing pigs once or twice a day is a great deal less effective than a spraying system.
Feed Troughs and Feed Storage
Efficient pig production requires a reliable supply of water and feed for a balanced diet. A large range of feedstuffs, including by-products and crop surpluses, may be used provided they are incorporated into a balanced diet. The requirements for feed change as the pigs grow and depend on the stage of production in sows. Table 10.11 shows the requirement where the feeding is based on a mix of meal feeds and can be used to estimate the required storage capacity for supply between deliveries.
Table 10.1 1 Feed and Water Requirement for Pigs
|Animal||Feed Intake (meal feed) kg/pig||Drinking Water Requirement litre/day|
|Sow in farrowing pen||5 - 7||22 - 27|
|Gestating sow||2 - 3||12 - 17|
|Boar||2.5 - 3.50||10|
A wide variety of feeding equipment is available for pig operations. The easiest to clean and sanitize are made from concrete, metal or glazed burnt clay. Concrete troughs are commonly used and can be pre-fabricated using a metal mould. The trough is often placed in the front wall of the pen as shown in Figure 10.35d, e and f. Although such an arrangement makes for a more difficult construction than to have the trough inside the pen it is usually preferred due to easier feeding and it also prevents the pigs from stepping into the trough.
The wall above the trough can be made either solid or open and can be either vertical or sloping inwards to the pen.
An open front improves ventilation in the pen but it is more expensive than a close-boarded wooden front as galvanised steel pipes have to be used for durability. In particular a sow confined in a stall of a farrowing crate will feel more comfortable if she is able to see in front of her. A sloping front will more effectively discourage pigs from stepping into the trough but it is more complicated and expensive to construct.
Two piglet feeders for use in the creep area are shown in Figure 10.36. The same types can be used for growing pigs up to 40 to 50 kg, but the dimensions will need to be increased. Metal is preferred, although a feeder made of wood can be satisfactory if cleaned regularly and thoroughly.
The requirement of drinking water is shown in Table 10.11. It is preferable to mix mealfeed with 1.5 to 2.1 litres of water per kg feed. The rest of the water can be given in the trough between feedings or in special drinkers. Clean water must be available to the pigs at all times, including the piglets in a farrowing pen.
Automatic drinkers are the most hygienic and can be used where piped water is available. There are two types, one which is placed above the feed trough and sprays into the trough when pushed by the pigs and the other type, which is operated by the pigs biting around it. This latter type is often placed in the manure alley or in the pen close to the manure alley to prevent the pigs from getting the resting area wet.
The pig pens must be cleaned once or twice per day. Provided suffcient bedding is used and the urine is drained away separately to a urine storage tank the solids may have a consistency, which allows it to be stacked on a concrete slab. Where little or no bedding is used or the urine is not separated, a manure storage slab of the type shown in Figure 10.22 can be used. Table 10.12 shows the manure production.
Figure 10.35 Feeding equipment.
Figure 10.36 Piglet feeders.
Poultry, including chickens, turkeys, ducks and geese, offers one of the best sources of animal protein, both meat and eggs, at a cost most people can afford. Chickens are the most widely raised and are suitable even for the small holder who keeps a few birds that largely forage for themselves and require minimum protection at night. At the other extreme, commercial farms may have highly mechanized systems housing thousands of birds supplying eggs and meat to the city market. In between are farm operations in a wide range of sizes with varying types of housing and management systems proportionate to the available level of investment and supply of skilled labor.
No single system of housing is best for all circumstances nor even for one situation. Some compromise will invariably have to be made.
The needs of chickens and later other classes of poultry will be discussed and a number of housing systems will be described along with the principal advantages and disadvantages of each.
General Housing Requirements for Chickens
Proper planning of housing facilities for a flock of laying hens requires knowledge of management and environmental needs in the various stages of the life of the chicken. A typical life cycle is illustrated in Figure 10.37.
The laying period may be up to 16 months, but in flocks held for commercial egg production the hens are normally culled after a laying period of 11 to 12 months or when the production has dropped to a point where the number of eggs collected per day is about 65% of the number of hens in the flock. It is true that the hens will come in to production again after a couple of month's moulting period, but the production is not as high and the egg quality is generally not quite as good as in the first laying period. Where prices of poultry meat are reasonable, it is usually more economic to cull all the hens after one year's egg production.
Table 10.12 Manure Production for Pigs
|Wet soild Manure||Urine||Total||Storage requirement for slurry|
|kg/day||kg/day||kg/day||m³ per day of storage|
|Dry sow and boar||2.0 - 2.5||4 - 5||6.0 - 7.5||0.011 or 0.013 per sow in the herd|
|Sow with litter||2.5 - 3.0||8 - 10||10 -13||0.018|
|Farrowing pigs - 45 kg||0.8 - 1.0||2.5||3.3 - 3.5||0.004 or 0.006 per growing/finishing pig|
|Finishing pigs 45 - 90 kg||1.5 - 2.0||4 - 5||5.5 - 8.0||0.008|
Figure 10.37 Typical life cycle of a laying hen.
The best site is one that is well-drained, elevated but fairly level, and has an adequate supply of drinking water nearby.
Regardless of the type or size of the housing system, the site for construction should be selected to provide adequate ventilation, but be protected from strong winds. An area under cultivation, producing low growing crops, will be slightly cooler than an area of bare ground. High trees can provide shade while at the same time actually increasing ground level breezes. Bushes planted at one windward corner and also at the diagonally opposite corner will induce air currents within the building to make existing bmise the heat from direct solar radiation.
Since all buildings used for poultry housing tend to produce odours, they should be located well downwind from nearby dwellings. If there are several poultry buildings in a group it is desirable to have them separated 10 to 15m in order to minimize the possibility of the spread of disease.
Brooding buildings should be isolated from other poultry buildings by 30 metres or more and be selfcontained in respect of feed supplies and storage of equipment. If the same person cares for both layers and growing birds, a disinfectant foot bath at the entrance to the brooding area is an added precaution. All buildings should be constructed on well-drained sites where drives and paths between buildings will not become muddy even during the rainy season.
The effects of temperature and humidity on the birds make it apparent that in most areas of East and Southeast Africa the principal environmental concern is to keep the flock as cool as possible. Shade, good ventilation with natural breezes, freedom from roof radiation and the indirect radiation from bare ground are all important. Only in a few high altitude areas does protection from wind and low temperatures become a significant consideration.
Humidity seems important in only two respects. Very low humidity causes objectionably dusty conditions and high humidity combined with temperatures above 27°C seems to interfere with the physiological cooling mechanism and increases the possibility of death.
Day old chicks require a temperature of 33° to 35°. This temperature is maintained for a week and is then gradually lowered to the ambient temperature by the end of 5 weeks.
In addition to providing a good environment, the housing should offer protection from predators and theft as well as the exclusion of rodents and birds. These latter two not only carry disease, but they can consume enough feed to make a significant economic difference.
The effect of light on egg production has been discussed earlier. Additional hours of light can be achieved by installing one 40W electric light bulb per 15m² floor space in a position about 2.2m above floor level.
More important than the hours of light, however, is the maintenance of the lighting schedule, since any sudden change in the length of the photo-period is likely to result in a significant drop in production. Fourteen hours of light throughout the laying period is optimum.
A schedule with gradually decreasing hours of light may be used in windowless houses for maturing pullets. This postpones laying, but results in larger eggs being produced from the start of laying.
In warm climates near the Equator, houses are open for natural ventilation, however, and the day length is close to 12 hours throughout the year. The result is that pullets start to lay at 14 to 18 weeks of age and egg size, which is small at first, gradually increases during the first 3 months.
Broiler houses are often lighted 24 hours per day to encourage maximum feed consumption and rate of gain.
Proper design and management of the poultry house can effectively contribute to the prevention of disease in the flock. In general it is best if the litter is dry but not too dusty. If no litter is used, the floor and wall surfaces should be designed so that they can be easily cleaned between flocks and stay reasonably clean during use.
In most hot climates there will be many more days when a cooling breeze is needed rather than protection from a chilling wind. A wall construction consisting of a solid base, which protects from indirect radiation from the ground, and an open space covered with mesh above it, is therefore preferred for all four walls in most types of chicken houses. A hessian or reed curtain that can be dropped on the windward side will offer extra protection and, if installed on the east and west, it may also protect from direct sunshine. An arrangement where the top end of the hessian is fixed to the wall plate and the bottom end attached to a gum pole around which it can be rolled when not in use, will provide for smooth operation. In high altitude areas off-cuts may be used on the gable ends, but 15 to 20mm spaces should be left between them to improve the ventilation. The width of the building should not exceed 9m for efficient cross ventilation.
Lower Wall Design up to 1000mm of solid walls can be made of any available masonry units. Bag washing will give a smooth easily cleaned finish, but adobe blocks will require the extra protection of plastering to prevent the birds from destroying the wall by pecking.
The Upper Wall Design to the total height of the wall, including the solid base should be about 2m. Gum poles treated with wood preservative and set 500mm deep in concrete are a practical means of supporting the roof and upper wall structure. Eighteen millimetre wire mesh is small enough to keep out rodents and birds. A tight fitting door is essential.
The floor in a poultry house may consist of gravel or well drained soil, but concrete is desirable because it is easily cleaned, durable and considerably more rat proof. A concrete floor should be 80 to 100mm thick and be made of a stiff mix, 1:2:4 or 1:3:5 concrete, placed on a firm base at least 150mm above ground level and given a smooth finish with a steel trowel.
Table 10.13 Recommended Minimum Floor, Feed and Water Space for Chickens
|birds/ m²||birds/ m²||birds/ m||birds/ m||birds/ m|
|Chicks and Pullets|
|1 - 4 weeks of age||15 - 20||25 - 30||40||40||150|
|5 - 10 weeks of age||8 - 11||12 - 15||15 - 20||25||75|
|11 - 15 weeks of age||5-6||7-8||9- 10||12||50|
|16 - weeks of age||3 - 4||5 - 7||7 - 8||10||40|
|Breeders||3 - 4||5 - 6||6 - 8||9||1 5|
|Layers||6 - 7||8||10 - 20|
|house||3||4 - 5|
|run||0.04 - 0.08||0.10 - 0.13|
|house||3||4 - 5|
|Deep litter floor||3 - 4||5 - 7|
|Wire floor||7 - 8||9 - 10|
|Combination floor||5 -6||7 - 8|
|Cages, incl. alleys||8 - 12||15 - 25||7 - 10|
Roof structure with a free span is desirable to avoid any inconvenience caused by roof supporting poles inside the building. Corrugated steel sheets are the first choice for roofing material because they are much easier to keep clean than thatch. Insulation under the metal roofing will improve the environment in the house. However, a thatched roof may result in even better conditions and can be used on narrow buildings. The roof overhang should be 500mm, or more, in order to give adequate protection from sun and rain. A ventilation opening along the ridge is usually supplied in layer houses, but not in brooding houses.
Housing Systems for Layers
The pullets are transferred from the rearing to the laying accommodation at 17 to 18 weeks of age and start laying when they are 20 to 24 weeks old. At the time of transfer they should be grouped according to size and stage of maturity.
There are five major systems used in housing of layers: Semi-intensive; deep litter; slatted or wire floor; a combination of slatted floor and deep litter; and cage or battery system.
Having considered the factors that affect the comfort, protection, efficiency and production of the birds, it is also important to design a system that is labor efficient, reasonable in investment and easy to manage. How well each of the systems fills the needs of both the chickens and the people supervising the operation should be the determining factor in the selection of an appropriate system for a specific situation.
Click here to continue
Contents - Previous - Next