Pig production is increasing in the world. To meet the demand and the economics of production, pig operations are becoming larger.

Many operations are under a contract system, with integrators supplying feed, management advice and marketing channels. Whole herd and year-round continuous production in confined, high-density, controlled environment facilities are becoming the most common production system.

At the same time, fly control has become more difficult. Each  growing and finishing pig produces 18 tons of feces and urine per year. This does not include the large amount of water used in flushing systems for manure removal.

The large number of pigs and the large amounts of manure in a limited area create the potential for large amounts of fly breeding.

 

 

Production

Pig production may be classified as:

• Sow-herd which includes feeder pig production and farrow to finish.
• Feeder pig finishing.

In either case, housing facilities vary from simple to specialized, high-density confinement.

The simplest is a pasture system usually operating to yield only two litters per year from one group of sows in a farrow to finish system. Feeders and waterers are provided and fly breeding may occur around them. This type of production is rapidly disappearing.

Most pig production occurs in either low-intensity or high-intensity confinement systems.

Low intensity involves the use of simple buildings (sometimes converted from other uses) with concrete floors (with or without bedding) and partially open fronts. There may be an outside run or pen area with feeders and waterers.

Drawing of low-intensity pig housing with outside pen.

Sectional view of low-intensity pig housing with pen.

Manure is removed from the building and outside pens by scraper or occasionally by flushing.

Runoff from the pens is collected in holding ponds  after passing through a settling basin if the system is properly constructed. Sometimes, however, there is no provision for collecting runoff, and areas adjacent to the pens become saturated with manure and produce flies.

Low-intensity housing may be used for sow herds or for feeder pig finishing. Separate buildings are usually used for growing-finishing and for farrowing. Often the low-intensity system involves two groups of sows for staggered production.

In the high-intensity confinement system, buildings are designed and built specifically for pig production.

Farrowing in a sow-herd system is closely scheduled and staggered, to allow continuous year-round production.

Sophisticated buildings and equipment may be used for feeder pig production, farrow to finish, or for feeder pig finishing only.

View of multi pens in enclosed, environmentally-controlled, high-intensity, partially-slotted floor pig facility.

In a sow-herd system, a separate building or partitioned portions of a building are used for gestation and breeding, farrowing, nursery, and growing-finishing.

Growing-finishing is either to feeder pig selling weight (18–28kg) or to market weight (about 100kg).

Buildings are either totally or partially enclosed, and equipped with fans and heaters. In mild climates, partial curtain sides may be used. Feeders and waterers are automatic.

The trend in pig production is towards totally enclosed, environmentally-controlled facilities. These allow the greatest production efficiency during all seasons of the year.

 

 

Manure

Manure removal and management with modern pig production facilities is accomplished with various arrangements of slotted floor made of wire mesh, concrete slats, or expanded metal. The floor may be totally or partially slotted.

In the partial slotted arrangement, the pens are about one-half concrete floor and one-half slotted.

Sectional drawing of a partially-slotted floor pig house.

Feeders and waterers are usually in the solid floor area, which slopes toward the slotted portion.

The manure falls through and is flushed through the slotted floor to a concrete pit area beneath. However, the supports along the margins of the slotted floor have no openings, and provide an area for manure accumulation and fly breeding.

The concrete pit is relatively shallow if it is frequently flushed to an outside holding pond.

An alternative is to use a deep pit beneath the slotted floor, to allow long-term storage of the manure slurry. Periodically, slurry is pumped out or allowed to flow by gravity, either to a lagoon or into a spreader for distribution on cropland.

The manure pit needs to be well ventilated (usually plenum and fans) to reduce odors and prevent the accumulation of gases  which are detrimental to the swine and corrode equipment.

The trend to larger pig production units and the use of specialized high-density confinement facilities has increased the problem of manure management and fly control.

Pockets of manure may accumulate along the edges of pens and may not be forced through the slotted floors.

Flushing out the manure beneath the slotted floor requires large volumes of water, and manure removal may not be complete.

If there is insufficient water in the deep pit, crusts and piles of partially dry manure may develop, which allow fly breeding.

Flushing manure into an anaerobic lagoon is a common method which is also used for dairy and poultry manure disposal. If the lagoon is too small, islands of solids will accumulate and provide a habitat for fly breeding.

In mild climates, partially slotted floors and manure flushing systems are also used in less sophisticated partially open-front buildings with curtain sides.

In simpler open-front buildings with outside pens, floors and pens are solid, and manure is either flushed out with hoses, or removed with scrapers.

In both of these housing systems there are many areas along the pen walls, beneath railings and fences, and in corners where manure can accumulate and provide a habitat for fly breeding.