Pigs – environment
Housing requirements for pigs.
Fences, gateways, gates and all facilities used to secure pigs must be constructed and maintained to reduce the risk of injury and attack by predators. Pigs may be housed or kept in intensive conditions provided the following conditions are met:
- Porkers must have a minimum of 1.5 m² per pig
- Baconer must have a minimum of 2.1 m² per pig
- The diet composition and quantities of feed must be recorded
- An area for sleeping with dry bedding must be provided. This sleeping area must be away from the dunging area
- Feed bins must be off the floor and cleaned regularly
- Faeces and urine accumulations must be removed daily
- Effluent must be treated and/or removed in accordance with local council regulations
- Normal diurnal pattern of lighting must be provided
- Opportunities for appropriate exercise must be provided
- Air must be of acceptable quality with respect to dust, chemicals and smells
- All pigs must be observed standing and moving during daily inspections.
Pigs require sufficient space to be able to extend their limbs while lying down and to move around, sleep, feed, dung and play with other pigs. They must have enough space to have a clean, dry place on which to lie.
Exercise is usually obtained through walking to water or food and interacting and playing with other pigs, which often becomes quite physical. Pigs are intelligent and inquisitive animals that should always be given some form of environmental enrichment such as hanging tyres, logs, balls hanging on chains and dirt to forage in. Growers and weaners, in particular, respond well to environmental enrichment and with enough space and stimulus, the need to carry out tail docking is greatly reduced.
Due to pigs foraging nature, they thrive in a free ranging environment where they can root in the dirt, forage, play, wallow and have access to sunlight which is vital for their health, however most pig farms keep their pigs housed inside. Where pigs are housed inside it is important to separate the feeding area from the dung area by placing food at the opposite end of the pen to where the pigs will dung.
The use of farrowing crates in piggeries is the traditional method of keeping the sow from laying on or trampling her piglets. As a result of the revision of the Model Code of practice for the welfare of animals: Pigs, this method is now not considered acceptable for schools. Any school that wishes to use farrowing crates must first seek written approval from SACEC.
This approval is sought by completion of Application form 5, Application for SACEC approval to house production animals intensively.
Schools are encouraged to develop management systems for farrowing that provide the following:
- Space for the sow to move around
- Nesting material for the sow and piglets
- Safe (creep) area for the piglets, reducing the chance of injury or death due to squashing.
There are a number of options that schools can use to develop a system that meets the physical and behavioural needs of the sow and piglets and suits the available resources.
In general, the pig production system should provide the maximum amount of space and environmental enrichment, and for dry sows, boars and growers access to the outdoors. When piglets are raised in less intensive conditions, the need for routine teeth clipping and tail docking is greatly reduced and may not be required at all.
ARRP Fact Sheet 1: Environmental enrichment for pigs
Providing some bedding, such as wood shavings, straw or rice hulls, is essential when pigs are kept on concrete to avoid abrasions. Under floor heating or heat lamps are also recommended for when sows farrow to provide warmth to the piglets. Some form of barricade is essential to provide the piglets with an area to go so that they do not get squashed by the sow. This can be provided by building sloping barricades off the walls of the pen that piglets can hide under.
From an animal behaviour and welfare point of view, free ranging piggeries are much more beneficial for pig health and welfare however many pig farmers argue that they are not nearly as efficient as traditional intensive piggeries. Pigs in intensive piggeries often develop behavioural problems such as tail biting due to boredom. In a school situation where a smaller number of pigs are kept and production efficiency is not quite as vital, it is encouraged to consider a free ranging set up for the pigs.
Pigs can be kept in artificial or natural light. When exposed to sunlight, shade should be readily available as pigs, in particular white breeds, are susceptible to sunburn.
Pigs are unable to sweat, so are very susceptible to heat stress. Pigs eat less when suffering heat stress and gilts and sows will be less likely to display oestrus in the heat of the day.
Ideal temperatures for farrowing sows is 18–21°C and growing piglets is 26–40°C.
Pens should be constructed of strong steel fencing. Fencing must be well maintained and latches on gates must be working. Fencing needs to be checked regularly to ensure that there is no loose wire or protrusions that will cause injuries to the pigs. Higher pens should be used for boars when they are penned next to gilts or sows.
Where pigs are housed outside, prefabricated pig wire should be used. Fences should be 1.2 metres high at least and pig netting should be at least 1 metre high, extending right to the ground. Fences will be need to be checked regularly to ensure the pigs are not rooting under the fences, allowing them to escape. It is recommended to use an electric wire standoff to keep the pigs away from the fences. Electric wires need to be appropriately signed.
Ventilation is very important when housing pigs to prevent the build up of poisonous gases such as ammonia. Ventilation should involve letting in fresh air without creating a draft.
Where pigs are free ranging, shelter is ideally provided by purpose built shelters with some shade provided by trees. Opportunities to wallow, allows pigs to cool off in summer and cover themselves in mud to reduce the chance of sunburn.
It is important to ensure that pigs kept in sheds do not overheat during hot periods. A sprinkler or drip system should be installed to ensure that they are kept cool while it is hot.
It is important to clean piggeries daily so that waste does not build up. Pigs are clean animals and where given the opportunity will dung in one area. However if pigs are housed very intensively, waste builds up very quickly. Solid waste should be removed using a shovel and then the area hosed. Alternatively, flushing drains, which self-clean, can be installed. A good drainage system that allows effluent to be removed or composted in accordance with local council regulations is essential.