Free-range pigs

Aerial view of circular system of free range paddocks

Aerial view of a free-range piggery paddock. This piggery uses the circular system.

A free-range piggery is a one in which the pig herd is rotated on pastures or cropland (e.g. sows are mated and farrow in paddocks, piglets are weaned and grown out in paddocks). There are variations to the production system on some farms (e.g. growers may be finished in shelters). Free-range pigs are typically kept in distinct groups based on age, sex, size, and stage of pregnancy. They receive the majority of their nutritional needs from prepared feed, with pasture or forage as supplementary feed. 'Free-range' implies that animals are not confined in enclosures - they may be fed in a shed, but normally have free access to paddocks. Pig meat products are typically targeted toward niche markets.

Under Queensland's Environmental Protection Act 1994, pig keeping is considered to be an environmentally relevant activity. As defined in the Environmental Protection Regulation 2008, pig keeping consists of keeping 21 or more standard pig units (SPU) of pigs. Keeping more than 21 SPU can only be carried out in Queensland on land where a development approval is in place. The operator of a pig keeping activity must also hold a registration certificate.

Free-range herds generally have lower set-up costs, but are slightly less productive in terms of weight gain per unit of food consumed (e.g. sows will eat more to compensate for the uncontrolled temperatures and there is greater potential for feed wastage) and a larger proportion of labour input is required.

Suitable pigs

A primary consideration in keeping pigs outdoors is their welfare, with the prevention of sunburn, the transmission of diseases from feral pigs, interbreeding with feral pigs and the predation of young pigs by other animals being significant factors that should be addressed.

It is preferable to source breeding stock that are fast-growing with good feed conversion and whose progeny will suit your market (e.g. some markets do not like pork products with dark hairs in the skin). Crossbred pigs with some pigmentation (not totally white) are generally better suited for free-range pig production, as they are reportedly less susceptible to sunburn and tend to be more hardy and robust than purebred pigs (i.e. larger litter size and higher survival rate).

A suitable cross-breed that meets the above requirements is the large white-landrace cross with about 25% duroc/Hampshire. This cross-breed offers sound growth and reproductive traits with that of improved meat quality. The duroc and Hampshire bloodlines provide some skin pigmentation.

Pigs with a quiet temperament are easier to handle and manage. As for any pig farming operation, you should consider the advantages of purchasing pigs that are free of some diseases.

Site selection and management

Climate

Preferable geographical areas for free-range pig farming are those with low rainfall (suggested less than 750 mm a year) or moderate rainfall throughout the year with no excessive heat in summer. Areas with concentrated rainfall patterns, combined with extremes of humidity and/or air temperature (particularly prolonged extremes), are likely to cause stress in pigs. While wallows may offer relief and, to a degree, protection against heat and sunburn, they are considered environmental hazards and a potential risk to pig health. Wallows should therefore be avoided.

Land requirement and landform

The amount of land required to operate a free-range piggery will be determined on a nutrient mass balance approach and is influenced by climate, soil type, cropping regimes within any keeping areas, land topography, pasture cover and SPU number kept within the areas. On-site vegetative buffer zones around sensitive sites like waterways will be required, as will appropriate separation between neighbours and the pig keeping activity.

These calculations can be done using the Free Range Piggery Assessment spreadsheet, which Intensive Livestock Environmental Regulation Unit (ILERU) officers can provide for free as well as pre-lodgement advice. This Excel spreadsheet allows you to enter the details of a proposed free-range piggery and calculate the required area needed to accommodate a number of pigs, as well as assess the environmental viability of a proposal using a range of scenarios including different numbers, soil types, cropping or grazing regimes. You can also use the Free Range Piggery Assessment spreadsheet to compare the proposed separation distances with the required separation based on the Separation Guidelines for Queensland Piggeries (PDF, 260.4KB).

Maximum stocking densities under the Welfare Code are 20-25 dry sows per hectare and 9-14 lactating sows with piglets per hectare.

Free-range piggeries should be located on relatively flat land with a gradient and soil type that will minimise soil, and therefore nutrient, erosion from the pig keeping areas to adjacent surface waters. Steep& slopes and soil types that are prone to erosion should be avoided due to the risk of soil erosion offsite particularly in wetter climates and on steeper slopes. Site topography also influences the potential for water logging and the potential for strong vegetative growth (which can use the accumulated nutrients) within the pig keeping area. Avoid land that is contaminated with poisonous plants and parasites that may affect pig health.

Surface and ground water

Surface water, such as dams and streams, may be at risk of contamination by run-off from free-range pig farms, or from the movement of pigs themselves. Finer soil particles that wash into earthen drains and/or watercourses, along with dung and urine, will add nitrogen, phosphorus and possibly pesticides to the water, causing potential environmental damage. You can minimise or prevent these impacts by bearing in mind the rainfall and flood records for the area and creating a landform and controlled drainage system to protect watercourses:

  • Site paddocks across slopes, and site tracks and gateways so they do not channel water into watercourses or beyond the site's controlled drainage areas or boundaries.
  • Use vegetative buffers between free-range production areas and localised surface water bodies and their catchment areas.
  • Install holding structures (e.g. holding/tailing ponds, bunded capture barriers, diversion banks) to divert or contain surface water run-off where creeks or watercourses may be at risk of contamination.
  • Install physical barriers to prevent pigs from making contact with water bodies and riparian zones.

In environmentally sensitive areas, you may need to demonstrate that a drainage system will be installed in order for your application to be assessed in your favour during the development application process.

Groundwater resources may be contaminated by deep percolation of nutrients and pathogens. This is likely to occur within wallows, where bulk manure is not distributed evenly over paddocks or where the nature of the soil profiles allows fast movement of nutrients deposited on the surface. To prevent ground water contamination:

  • do not allow wallows to be formed (fence off areas where wallows are starting to occur and commence rehabilitation of the affected area)
  • contain manure stockpiles (if any) within controlled bunded areas that are designed with impermeable pads/barriers to protect the soil.

Any lands with sandy or loamy soils that are located very close to waterways or lands that contain shallow groundwater may be unsuitable for the establishment and operation of free-range piggeries.

Stored water bodies with high concentrations of nutrients/contaminants (e.g. run-off holding ponds) may require managed irrigation over suitable adjacent land where the nutrients can be sustainably used.

Separation distance and community amenity

All piggeries should be sited with an adequate separation distance to avoid unreasonable interference with the comfortable enjoyment of life and property, both on and off the site. Specifically, odour, dust and noise from the operation must not adversely impact upon neighbouring properties/communities. A well-established and maintained vegetative buffer zone can improve visual amenity, odour dispersion and reduce dust and noise.

Also site piggeries at an adequate separation distance from other piggeries and from roads on which pigs are transported to reduce the risk of disease transmission - as part of on-site biosecurity plans.

Uncontrolled fly populations in free-range piggeries may also lead to community amenity issues. Increased fly populations can result from inadequate waste management practices that allow flies to breed. Minimise fly numbers by ensuring that:

  • all manure is not left to accumulate to create odour, nuisance or potential environmental harm and is managed in accordance with the site's environmental management plan
  • all spoilt feed around feed troughs is regularly cleaned up in accordance to the site's environmental management plan and animal welfare practices
  • all dead carcasses are to be disposed of as early as possible and in an environmentally sustainable manner (e.g. an approved composting area).

For community health reasons, manure must be kept at a manageable level and not allowed to accumulate excessively. A variety of pathogens may be blown from uncontained pig manure and effluent on free-range piggeries to neighbouring premises. The transfer of pathogens may be reduced through general cleanliness of the free-range piggery and appropriate buffers (e.g. vegetative buffer zone).

Download the Separation Guidelines for Queensland Piggeries (PDF, 260.4KB) for further information (or obtain a free copy from ILERU officers). 

Stocking density and rotation

The stocking density varies depending on the capacity of the land to sustainably accommodate the herd - to assimilate the nitrogen and phosphorus deposited by the pig herd on the pig keeping areas. Issues such as soil type, soil erosion potential, cropping potential and therefore nutrient removal, ground cover, slope and climate must be taken into consideration when planning a free-range pig production system. Without careful planning and management, the operation of a free-range pig farm may lead to nutrient accumulation within the soil profile of the pig keeping areas and increase the risk of nutrient and sediment contamination of ground/surface waters.

Overloading occurs when the rate of nutrients added to the soil through animal wastes (e.g. manure) and spilt feed exceeds the rate of nutrient export through harvesting of crops, volatilisation and leaching etc. Plan your stock rotation as part of a whole-farm program and minimise overloading by incorporating cropping and/or pasture programs to remove the excess nutrients added to the soil by pig production and to encourage land restoration (e.g. plant and harvest at least one crop between rotational groups).

Free-range pigs will create soil exposure through rooting activity and the constant trampling of hooves. To prevent soil erosion in exposed areas, it is preferable to spell any affected paddocks before the ground cover is reduced to less than 40%. Do not restock the affected paddock until sufficient ground cover returns in the exposed areas.

The trampling of hooves will also cause soil compaction in high traffic areas, which may hinder the establishment of crops. To reduce compaction, consider using a deep litter shelter, or similar, to house pigs during wet weather when the soil is most vulnerable to compaction and shifting feeders, drinkers and shelters. Methods for repairing soil compaction include deep ripping and adding gypsum prior to planting.

Nose rings can be fitted to pastured animals to aid in reducing the rate at which paddocks are rooted-up thus destroying the groundcover and exposing the soil. The Model Code of Practice for the Welfare of Animals: Pigs; 3rd Edition states that nose ringing should be avoided, but 'may need to be performed as a last resort, to prevent adverse effects to the environment' and that 'rings should be placed through the cartilage of the top of the snout or the tissues separating the nostrils'.

Facilities and layout

Plan the layout of your free-range piggery so that the groups of pigs can be rotated (move younger pigs onto 'cleaner' ground) through different paddocks easily and with minimum stress to both pigs and operators (e.g. paddocks surrounding a central handling area and connected by practical laneways, such as in a circular wheel pattern with hub (such as the image at the top of this page) or a rectangular pattern with central lane. A stock handling facility (i.e. with a concrete floor and a crush) may be required for vaccinations, veterinary treatments and weighing etc. as well as spare paddocks for sick pigs. Boar service paddocks may also be required.

Shade and shelter

At all times, free-range pigs must have access to dry, clean, shady shelter (e.g. huts) to protect them from rain, wind, heat and cold. The space allowances of shelters must comply with the Model Code of Practice for the Welfare of Animals: Pigs. These are minimum space allowances: 1.2-1.5 m² per dry sow, 4-6 m² per lactating sow with piglets and 2 m² per boar. Providing extra space and, in particular, more than one shelter for a group of pigs will help to minimise bullying.

In cooler climates, extra bedding will help pigs handle the cooler conditions, while in warmer climates, well-ventilated shade is essential, particularly for pregnant sows. Metal roofs can be painted white to reflect heat and low volume sprinkler systems may help to cool the pigs. Also consider the location of shelter belts of trees to protect pigs from cool winds in winter and the sun in summer.

Regularly shifting the position of shelters will assist in reducing localised denuding of vegetation and achieve a more uniform distribution of nutrients.

Fencing and protection

The fences of pig paddocks are typically electric; however, mesh, barbed or plain wire fences, or a combination of electric and wire fences are also suitable for confining pigs. Fences need to be adequate so that pigs cannot jump over, dig under or crawl between the wires. Some free-range piggeries use temporary fencing and shift these to fresh land instead of rotating the paddocks. Whatever the type of fencing you use, train the pigs when they are young or when first purchased to respect the fences that border their paddock (e.g. by using an electric fence in front of a 'solid' fence in a small training paddock).

A quality permanent fence is recommended at the outer boundary to stop pigs escaping the property altogether and to prevent stray and feral animals (e.g. feral pigs, dingoes and dogs) entering. Feral pigs may introduce diseases to your free-range pig herd and the wild boars may mate with your free-range sows, leading to lower productivity. Dingoes, feral dogs and wandering domestic dogs, which are often attracted to free-range piggeries by the noise of pigs and the scent of carcasses, may attack and harass your pigs, thereby increasing pig stress and pig losses. The erection of a permanent, pig/dingo/dog-proof fence, effective disposal of carcasses and, if necessary, eradication programs, should minimise these problems.

Where the risk of fire is high, you should also establish firebreaks around your free-range piggery.

Feed, feeding and water

All classes of pigs need to be fed formulated, balanced diets that meet their respective nutritional needs. Pasture alone does not provide sufficient nutritional benefit for pigs (generally only 0.2-0.3 kg per standard pig unit (SPU) per day), particularly for young weaners that require a diet high in nutrients. During cold weather, pigs may require extra feed.

Swill feeding is illegal in Australia because of the serious risk of introducing a devastating exotic disease (e.g. foot and mouth disease). Swill feeding includes using food (or food scraps) containing or possibly having had contact with animal matter (e.g. from restaurants, hospitals and domestic households) as feed for pigs, poultry or ruminants.

Adequate feeding space and watering points are essential to reduce bullying, avoid stress and ensure that younger or more timid pigs are not deprived of food or water. Free-range pigs may be fed either on the ground or in troughs (to minimise feed wastage) in a designated area of the paddock on a prepared pad (earth or concrete). If pigs are not fed on a prepared pad, regularly changing the feeding area will assist in reducing localised denuding and achieve a more uniform distribution of nutrients. Feed in the form of large pellets is less wasteful than meal.

Vermin, such as rats and mice, can be attracted to a piggery. All feed storage areas must be vermin-proof. Where feed is provided ad lib (e.g. for young growers), use feeders that are designed to prevent vermin from accessing the feed (i.e. with flaps that cover the feeding space and the filling area of a hopper). An eradication program may also be necessary to control the vermin in and around the piggery.

Drinking water of adequate quality and sufficient volume must be provided for the pigs at all times. This water can be sourced from appropriately licensed sources, such as bores, dams, water courses, or reticulated supplies. Watering points should be managed to ensure that wet patches from spilt water and leaking troughs do not develop. Wet patches must be avoided because they are prone to develop into wallows which can become odorous and potentially contaminate soil and water resources. Water that has been heated by the sun to a high temperature (e.g. through exposed polypipes) is not suitable for pigs to drink. If a pig doesn't drink enough water, their feed intake, and thus production, will be reduced, as well as impacting on their welfare.

Breeding free-range pigs

It is imperative that the breeding stock are protected from the sun. Sunburnt sows will not 'stand' to a boar. In addition, heat stress may cause pregnant sows to abort and boars to be less fertile (heat stress can occur even if the pigs are not sunburnt).

Gilts should weigh at least 130 kg liveweight and be about 30-35 weeks of age at the time of their first mating. Sows can be grouped by stage of pregnancy to allow better management (e.g. be fed the most suitable diet, checked for returning to heat). Sows that are young (e.g. a group of sows pregnant with their first litter) or in poor condition can be separated from the main group(s) so their feed intake can be adjusted and closely monitored.

Boars may be kept separate to sows or a few boars may be put with a group of sows in paddock of around 0.5 ha. However, hand mating (fully supervised) is preferable to running boars with sows in order to achieve quality matings, spread boar workload and to accurately predict farrowing times. Hand mating may occur in a mating area adjacent to the sow paddock. Alternately, artificial insemination may be used.

A group of pregnant sows at the same gestation stage may be kept separate or may be combined in larger groups. Sows may be mixed, in a large space to allow sorting of hierarchy, at weaning, in the first days after mating or not until 28 days after mating (to reduce possible embryo loss due to mixing stress). A boar can be put with such groups to catch sows returning to oestrus at six weeks post-mating.

Approximately seven days before pregnant sows are due to farrow, move them to a paddock that has clean, warm and draught-free farrowing accommodation with ventilation for the sows in hot weather (i.e. shutters high in the walls of the farrowing huts) and sufficient bedding to keep piglets warm. To avoid overlaying of piglets and, hence, reduce piglet mortality, guard rails are recommended on the walls of farrowing huts (225 mm above the floor and 300 mm from the walls).

Herd health

As for any piggery, source breeding stock from high health status herds. All breeding stock should be vaccinated against at least leptospirosis, parvovirus and erysipelas. In addition, a regular and effective control programfor worms and mange should be in place for all stock.

Management practices

In general, most management practices of free-range piggeries are similar to those of fully housed piggeries; however, managers of free-range piggeries should have expertise in both pig and pasture management. Staff of free-range piggeries also need to be prepared to work in all weather conditions.

Permits and approvals

Under environmental and biosecurity legislation in Queensland, free-range pig farming holds the same legal status as all other methods of pig farming:

  • Pig keeping is identified under the Environmental Protection Act 1994 as an environmentally relevant activity (ERA), as it has the potential to cause environmental harm. The keeping of more than 21 standard pig units (SPU) can only be carried out on land where a development approval is in place to authorise the activity. Therefore, all new piggeries, or those considering expansion, will need to obtain a development approval and registration certificate under the Sustainable Planning Act 2009 and the Environmental Protection Act 1994 before any development takes place. Officers from the Intensive Livestock Environmental Regulation Unit (ILERU) of the Department of Agriculture, Fisheries and Forestry are delegated authority for assessing applications for pig keeping activities. To enquire about development approvals, please contact ILERU on 07 4688 1605.
  • The operator of a pig farm must hold a registration certificate under the Environmental Protection Act 1994. To apply for a registration certificate, contact ILERU.
  • Any person that keeps one or more pigs must, in accordance with the Stock Act 1915, register their property with the Department of Agriculture, Fisheries and Forestry.

Acknowledgement

Thanks to Ian Barugh, Massey University, New Zealand for information and to piggery operator Geoff Terry, Tasmania for photos.

Further information

Last updated 19 July 2011