A good selection program, coupled with adequate nutrition, will provide producers with sows and gilts that have the potential to farrow and raise large litters. Without adequate housing, this potential will never be realized. Adequate housing and environment are essential for improving reproduction.
Once females are bred, housing is important for the normal maintenance of pregnancy. While confinement provides more environmental control, both confinement and pasture-drylot gestation facilities are adequate with good management.
Individual housing of females or group housing with individual feeding stalls or crates is best. Under group pen conditions, competition for feed results in low intake for gilts and small sows. Sows also fight, leading to stress and reduced litter size and farrowing rate.
When housed individually, feed intake can be controlled. Individual feeding also gives the producer a chance to check each sow and gilt at least once each day. Females in poor condition can be fed more, while those that are too fat can be fed less. Loss of appetite is the first sign of many disease problems and is easier to detect with individual feeding.
Group penning, while in several ways not as good as individual stalls, can work. Sows and gilts must be sorted by size and body condition. Thin sows should be penned together. Limit the group size to four to eight. If you wean a group of twenty sows, you should have at least four pens in breeding and gestation.
A compromise housing design is individual penning for the first 4 to 5 weeks after breeding, and group penning after that. This arrangement reduces or removes the stress associated with fighting during the critical period after breeding, while providing inexpensive facilities for most of gestation.
The temperature of the gestation facilities is critical, especially just after breeding and 2 to 3 weeks before farrowing. Heat stress at these times will reduce litter size. Temperatures of 85 degrees F or more just after breeding can result in an embryonic death rate of 30 to 40 percent. Just before farrowing, the same temperature may increase the number of stillborn pigs.
In confinement, good ventilation combined with sprinklers is normally adequate to keep sows and gilts cool. In pasture-drylot operations, temperature control is more difficult. Providing a shed with an insulated roof can reduce the temperature 5 degrees to 10 degrees F. Where possible, sprinklers and fans should also be used.
For farrowing barns, a drip system with air movement from mechanical
or natural ventilation keeps sows cool in all but extreme temperatures.
The drip system should supply 0.5 gallon of water per hour to each crate.
For maximum cooling and minimum water on the pigs, attach the drip emitter
to the crate so the water drips on the sows' necks.