s4ag-pigs

Pig management decisions — pasture, woodland, and orchard systems; rotational management; breed selection; housing; nutrition; and health basics. Use when the user asks about pigs, raising pigs, pastu

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Pigs

Managing pigs well means managing their destructive power intentionally. Pigs are the most effective land-clearing and soil-working animal on the farm — and the most damaging if left in one place too long. The goal is to harness that rooting energy as a tool: moving pigs through areas in rotation, letting each area fully recover, and integrating pig impact into the broader farm system so that they build the land rather than degrade it.

How this skill works: Each sub-tool pauses at a Checkpoint to confirm the assumptions it is about to build on before producing output. A recommendation built on a wrong assumption wastes time and money — confirm the checkpoint before acting. Each sub-tool ends with Next steps — the skills worth running once you have acted on this one.


Expert Lineage

The thinkers whose frameworks underpin this skill — and what they specifically discovered that changes how you farm.

Joel Salatin — Multi-Species Stacking Salatin demonstrated at Polyface Farm that pigs, when moved behind cattle, perform "sanitation" grazing in the manure-rich areas cattle leave behind — consuming fly larvae and parasites, scratching and aerating the soil, and integrating manure into the soil profile. His most actionable finding: pigs as the third species in a stacked rotation reduce parasite load and fly pressure across the entire livestock enterprise, not just for the pigs. The practical implication is that pig placement in the rotation is as important as duration.

Forrest Prichard — Integration on a Diversified Farm In Gaining Ground, Prichard documented the financial and land-health trajectory of integrating pigs into a failing diversified farm operation. His specific contribution: pigs positioned in the right place at the right time function as "free labour" — clearing scrub, preparing seedbeds, and cycling nutrients — in ways that would otherwise cost machinery hours. The practical implication is that pig value is not just in the meat; it is in what they do to the land between arrival and slaughter.

Allan Savory — Recovery Period as the Key Variable Savory's Holistic Planned Grazing research established that recovery time — not stocking density per se — determines whether land degrades or improves under animal impact. While Savory focused on ruminants, the principle applies directly to pigs: the damage from pigs staying one week too long in an area exceeds the damage from three times the stocking rate at correct duration. The practical implication is that the paddock a pig herd just left is more important to monitor than the paddock they are in.

Elaine Ingham — Soil Biology Under Rooting Pressure Ingham's soil food web research identifies fungal hyphal networks as the most fragile component of soil biology — and pig rooting as the most comprehensive way to destroy them. Her finding: a single pass of pigs at high density on light soil can set fungal recovery back 2–3 years. But the same disturbance on compacted, bacteria-dominated soil can function as a biological reset, creating the aeration and organic matter incorporation conditions that allow biology to recolonise. The practical implication is that pig rooting is only beneficial when used on ground where disturbance is the correct prescription.

Weston A. Price — Nutritional Density and Foraging Diet Price's comparative research on traditional versus industrialised food systems established that pigs raised on diverse foraging diets — mast, roots, grubs, fresh pasture — produce meat with dramatically different fat-soluble vitamin content, particularly vitamins A, D, E, and K2. His specific finding: lard from woodland-pastured pigs was among the most vitamin D-dense foods recorded in traditional diets. The practical implication is that access to diverse forage is not just a welfare preference — it is the primary determinant of product quality and marketable differentiation.

Mark Shepard — Restoration Agriculture and Woodland Integration Shepard demonstrated at New Forest Farm that pigs integrated into agroforestry systems — running under tree rows at the right season — can suppress grass competition around young trees, cycle orchard drop, and convert woody debris into fertility without the capital cost of mulching or mowing. His specific finding: pigs running the tree rows in autumn, after the harvest window closes, extend the productive season of both the pig enterprise and the orchard enterprise simultaneously. The practical implication is that the calendar matters as much as the paddock map.


Which tool fits

You need to... Tool
Choose between pasture, woodland, and orchard integration systems system-selection
Design a rotation that prevents land damage rotational-management
Work out what and how to feed pigs on or near your land nutrition
Design or choose shelter and housing for your system housing
Identify and address worms, skin problems, or lameness health-basics

Routing Decision

  • Starting out — unsure what kind of pig system fits your land → system-selection
  • Have pigs, concerned about land damage or recovery → rotational-management
  • Feeding costs are high, want to reduce purchased feed → nutrition
  • Building or choosing housing for a new pig enterprise → housing
  • Pig is showing signs of illness, worms, or injury → health-basics
  • Integrating pigs into an existing orchard or agroforestry system → system-selection, then rotational-management

System Selection

Matches the right pig enterprise model to the land, the farmer's goals, and the available infrastructure.

The three main systems for outdoor pigs each have different requirements, different land-health outcomes, and different suitability to farm types. Choose the system first — then design the rotation and infrastructure within it.

System comparison:

System Best for Land type Infrastructure Soil health outcome Risk
Pasture pigs Meat production at scale Open grass paddocks, moderate slopes Electric fencing, arks Positive if rotated; destructive if static Wet soil damage in winter
Woodland / forest pigs Mast-fed pork, orchard integration Established woodland or orchard Shade and shelter available; electric or post and wire Litter incorporation, mast cycling; root damage risk to tree roots Tree root damage at high density
Orchard integration Autumn windfalls, fertility cycling Established fruit orchard Existing orchard infrastructure Windfall cleanup, fertility; blossom damage if timed wrong Spring timing — pigs must be out before blossom

Breed matching to system:

Breed Temperament Rooting tendency Feed conversion Best system fit
Tamworth Active, alert High Moderate Woodland, scrub-clearing
Large Black Docile, hardy Moderate Good Pasture, orchard
Berkshire Calm, good forager Moderate Good All systems; premium meat quality
Oxford Sandy and Black Hardy, good forager Moderate-high Good Pasture and woodland
Gloucester Old Spot Docile, orchard-bred Low-moderate Good Orchard integration
Commercial cross (LW x LR) Variable Low Excellent Pasture systems where fast throughput matters
Kunekune Very docile, grazes rather than roots Very low Moderate (grass-based) Pasture; low land-damage system; mixed livestock

Kunekune as a low-damage option: If soil biology preservation is a priority and rooting capacity is not needed as a land tool, Kunekune pigs are the outlier in the breed table. They graze grass rather than root soil, have low maintenance costs, and suit mixed systems where pig presence is wanted but rooting is not.

Scale guidance:

  • Under 0.5ha: enterprise is viable only with very tight rotation and rapid throughput (weaner-to-finish in one season). Assess land carefully.
  • 0.5–2ha: viable for a small breeding herd with proper rotation. 2–4 paddocks minimum.
  • Above 2ha: sufficient for a productive enterprise with genuine recovery periods. Design the paddock map before acquiring stock.

Checkpoint — confirm before finalising:

  • What is the primary goal: meat production, land preparation/clearing, orchard integration, or all three?
  • What land type and size is available — open pasture, woodland, orchard, mixed?
  • What is the production scale — weaners finished once per year, or a breeding herd producing piglets on a cycle?

Matching the wrong system to the land type produces predictable damage — a high-rooting breed on a small orchard, or a pasture system run on unsuitable wet soil, causes land damage that takes years to recover.

Output:

PIG SYSTEM RECOMMENDATION
Farm context: [land type, area available, primary goal]

Recommended system: [pasture / woodland / orchard / mixed]
Breed recommendation: [breed(s)]
Rationale: [2-3 sentences connecting system, breed, and land type]

Infrastructure required:
- [fencing type and specification]
- [shelter/housing]
- [water provision]
- [feeding infrastructure if needed]

Production model: [weaners only / breed and finish / store pigs bought in]
Approximate stocking density: [pigs per hectare, system-appropriate]

Key constraints to manage:
- [constraint 1]
- [constraint 2]

Next steps:

  • Run rotational-management (within this skill) to design the paddock map and rotation schedule.
  • /s4ag-livestock — if pigs are joining an existing grazing system, integrate the pig calendar with the whole-farm grazing plan.
  • /s4ag-agroforestry — if woodland or orchard integration is the goal, design the tree system and the pig integration together.

Rotational Management

Designs a rotation that uses pig impact intentionally and prevents land degradation.

Rotation is the single most important management variable for outdoor pigs. Static pigs degrade land in proportion to the time they are on it. Moved pigs — in the right area, at the right density, for the right duration — can be the most effective land improvement tool on the farm.

The core principle: Move pigs before the land shows damage, not after. By the time the soil looks bare and poached, the fungal networks are already gone and recovery is measured in months, not weeks.

Rotation design — step by step:

1. Assess available land. Map all areas available for pig rotation. Note: soil type (clay vs sandy vs loam), drainage status, existing vegetation cover, and any areas that must be protected (young trees, watercourses, seed crops).

2. Calculate minimum paddock size. As a starting point: 0.1 ha per adult pig at any one time, with at least 3 paddocks in rotation. This is a floor — adjust based on soil type and season.

  • Sandy, free-draining soil: this stocking density is workable.
  • Heavy clay: reduce by 30–50%, especially in wet months.
  • Dry summer conditions: can push density higher temporarily.

3. Set rotation duration. Duration in a paddock is more important than area. A useful rule: leave when vegetation cover drops below 50%. Never wait for bare soil.

Typical rotation sequences:

System Time in paddock Minimum rest period Paddocks needed
Fast rotation (summer, good growth) 2–3 weeks 8–12 weeks 4–6
Standard rotation 3–4 weeks 10–14 weeks 4–5
Winter / slow-growth 2–3 weeks maximum 16–20 weeks 6–8
Scrub-clearing (intentional damage) Until task complete 12–18 months Purpose-specific

4. Manage the resting paddocks. Rest periods are where the land heals. During rest:

  • Oversow bare patches with a fast-establishing grass or clover mix.
  • Do not apply fertiliser to resting paddocks — the pig manure provides it.
  • Do not run other heavy animals over the paddock during recovery.
  • Delay re-entry until sward height is 15–20cm.

5. Seasonal adjustments.

  • Spring: soils are wet. Reduce density and duration significantly or keep pigs in housing until soil firms.
  • Summer: fastest recovery. Tight rotations work well. Watch water provision.
  • Autumn: move pigs onto scrub-clearing or orchard paddocks to use the season purposefully.
  • Winter: highest damage risk. Consider a sacrifice paddock (one area accepted as a write-off) to protect the rest. Or bring pigs indoors if the system supports it.

Using rooting as a tool: Pigs can be placed intentionally on areas designated for clearance or soil preparation. This is distinct from production rotation — these areas are written off for the season and managed as a land-prep exercise, not as production ground. Uses include:

  • Scrub and bramble clearance before replanting.
  • Bracken control on upland areas.
  • Breaking compacted ground before sowing.
  • Windfall management in orchard floor.

Allow 12–18 months minimum recovery before returning to production use after intentional clearance work.

Monitoring recovery:

Indicator Healthy recovery Flag for concern
Vegetation cover Returning within 4–6 weeks Bare soil at 8 weeks
Earthworm count (spade test) 5+ per 30cm square at 6 weeks Fewer than 3 at 8 weeks
Sward height 15cm+ at 10 weeks Less than 5cm at 10 weeks
Soil surface Firm, crumbling structure Still poached / puddled at 6 weeks
Smell Earthy, no ammonia Persistent ammonia or sulphur

Checkpoint — confirm before finalising:

  • What is the current season and soil drainage status? This determines what rotation duration is safe right now.
  • How many paddocks or areas are available, and what is their approximate size?
  • Is the goal sustainable production rotation, or is this an intentional clearance project?

Designing a rotation without knowing the paddock count and soil type produces a plan that cannot be executed — confirm these first.

Output:

PIG ROTATION PLAN
Date: [season / month]
System: [pasture / woodland / orchard]

PADDOCK MAP
Paddock 1: [location / area / current status]
Paddock 2: [location / area / current status]
Paddock 3: [location / area / current status]
[add as needed]

ROTATION SCHEDULE
Week 1–[X]: Paddock 1
Week [X]–[Y]: Paddock 2
[continue]

Stocking density: [pigs per hectare]
Maximum time in paddock: [weeks]
Minimum rest period: [weeks]

RECOVERY ACTIONS
Bare patches: [oversow with — species and rate]
Re-entry trigger: [sward height / visual indicator]

WINTER PLAN
[Sacrifice paddock / housing / reduced density approach]

MONITORING DATES
Check paddock 1 recovery: [date]
Re-entry assessment: [date]

Next steps:

  • Run housing (within this skill) to ensure shelter is available for each paddock position.
  • /s4ag-soil — if recovery is slow, assess whether the food web needs active support through compost or biological inoculants.
  • /s4ag-fencing — rotational pig management requires moveable fencing; design the infrastructure to support the paddock plan.

Nutrition

Works out what to feed pigs given the system, the land, and the goal of reducing purchased feed.

Pig nutrition has two layers: what the animal needs physiologically, and what is available from the system. The goal of this sub-tool is to maximise the forage and on-farm contribution to pig nutrition before calculating what remains to be purchased.

Nutritional requirements by stage:

Stage Dry matter intake (% bodyweight) Crude protein (% DM) Energy (MJ ME/kg) Key nutrients
Weaner (8–20kg) 4–5% 18–20% 13–14 Lysine, calcium, phosphorus
Grower (20–50kg) 3–4% 16–18% 12–13 Lysine, balanced minerals
Finisher (50–100kg) 3% 14–16% 12 Energy, fat deposition
Dry sow 2% 14% 11–12 Calcium, phosphorus
Lactating sow 4–5% 18% 13–14 Energy, protein, calcium

What different systems contribute to diet:

System Forage contribution to diet Quality Limitation
Permanent pasture (good sward) 10–30% of total diet Moderate protein, high moisture Low energy density; cannot replace grain
Diverse pasture (herbs, clover, chicory) 20–40% of total diet Higher protein and minerals Seasonal — summer/autumn peak
Woodland / mast (acorns, chestnuts, beech mast) Up to 100% during mast season Very high fat, high energy Short season (6–10 weeks); annual variation
Orchard windfalls Variable, up to 40% short-term High sugar, moderate energy Short season; adjust for sugar balance
Roots and tubers (kale, fodder beet, mangel) 20–40% Good energy, moderate protein Water content — weigh on DM basis
Household / kitchen waste Variable Variable Legal restrictions apply (see note)
Surplus dairy / whey Supplement-level High protein (whey) Source-dependent; check regulations

Legal note on kitchen waste: In many jurisdictions (UK, EU, Australia), feeding catering waste or kitchen scraps to pigs is prohibited or heavily restricted due to disease risk (African Swine Fever, Foot and Mouth transmission vectors). Check current national and regional regulations before feeding any material that has contacted meat products. On-farm vegetable waste, surplus produce, and dairy products from the same farm are generally lower risk — but confirm local rules.

Reducing purchased feed — practical steps:

  1. Assess the system contribution first. Walk the paddocks before buying feed. Pigs on good diverse pasture in summer may need 30% less concentrate than pigs on poor rye grass monoculture.

  2. Use mast strategically. If woodland is available, plan the finishing period to coincide with mast fall (October–December in the northern hemisphere). Acorn-finished pigs have higher oleic acid content in the fat — a genuine quality premium.

  3. Grow fodder crops. Fodder beet, kale, and mangels are low-cost to grow and can replace a significant proportion of purchased feed in autumn and winter. Trial a small area in the first season to test yield before committing.

  4. Balance the ration. Pigs on high-forage diets often need protein supplementation. Fishmeal, soya, or field beans (home-grown) are the most common protein sources. Home-grown field beans at 25% of the ration replace most of the purchased protein in a growing pig ration.

  5. Formulate a simple ration. For a finisher on a pasture system:

    • 50–60% cereal (wheat, barley, oats)
    • 15–20% protein meal (soya, field beans, fishmeal)
    • 10–20% on-farm forage contribution (credited at DM equivalent)
    • 3–5% mineral/vitamin premix

Feeding system — options:

Option Best for Pros Cons
Ad lib (hopper) Finishing groups Reduces labour; pigs grow at maximum rate Higher feed conversion; risk of overfat
Twice daily hand feeding Small herds; mixed age groups Control over intake; monitor individual pigs Higher labour
Once daily Pasture systems, summer Acceptable for finishers on good forage Less suitable for weaners or lactating sows
Electronic sow feeder Breeding herds of 10+ sows Individual feeding; reduces aggression Capital cost; maintenance

Water: Pigs drink 3–5 litres per kg of dry feed. Water is the most commonly underestimated nutritional input — shortage reduces growth rate faster than any feed deficiency. Check water availability in every paddock position before moving pigs.

Checkpoint — confirm before finalising:

  • What stage of production are these pigs at — weaners, growers, finishers, or breeding stock?
  • What does the current system contribute to diet — pasture type, any mast or forage crop available?
  • Is there a target of reducing purchased feed, and if so, what on-farm resources are available to use?

Without knowing production stage, the ration calculations cannot be calibrated — weaners and finishers have very different requirements.

Output:

PIG NUTRITION PLAN
Production stage: [weaner / grower / finisher / breeding]
System: [pasture / woodland / orchard / mixed]
Number of pigs: [number]

FORAGE / ON-FARM CONTRIBUTION
[Source]: [estimated % of diet] [season available]
Total estimated on-farm contribution: [%]

BASE RATION (per pig per day, DM basis)
Cereal: [kg] [source]
Protein: [kg] [source]
Forage credit: [kg DM equivalent]
Mineral/vitamin premix: [g]
Total DM: [kg]

WATER REQUIREMENT: [litres per pig per day]

FEED COST ESTIMATE
Purchased feed: [kg/week for group] [estimated cost/week]
On-farm saving vs. full purchased diet: [estimated %]

FODDER CROP OPTION
[If applicable: crop, area needed to replace X% of purchased feed]

Next steps:

  • /s4ag-soil — forage quality is determined by soil fertility; improve the pasture by improving the soil.
  • /s4ag-agroforestry — if mast production is limited, plan a long-term woodland establishment to build the mast resource.
  • Run health-basics (within this skill) — nutritional deficiencies and parasite burden are often confused; assess health alongside nutrition.

Housing

Designs or selects appropriate shelter for pigs in an outdoor system.

Outdoor pigs need protection from sun, wind, rain, and cold — but not the complex indoor housing of intensive production. The right outdoor shelter is simple, moveable where possible, and matched to the system.

Housing requirements by system:

System Minimum shelter requirement Ideal Notes
Summer pasture Shade structure + dry lying area Moveable ark with deep straw Pigs sunburn easily — shade is welfare-critical
Year-round pasture Insulated ark with deep straw, windbreak Moveable farrowing arc + store arks Winter welfare requires dry, draught-free bedding
Woodland Natural canopy usually sufficient Supplementary shelter for farrowing Monitor for hypothermia in piglets during wet cold periods
Orchard Light seasonal shelter Moveable ark Arks must be moveable — orchard use is seasonal

The pig ark — the standard outdoor shelter:

An ark is a semi-circular corrugated metal or timber structure, open at one or both ends, large enough for pigs to lie in and turn around. Standard specifications:

  • Weaner group (10 pigs to 30kg): 2.0m x 1.2m ark, minimum
  • Grower/finisher group (10 pigs to 100kg): 2.4m x 1.8m ark, minimum
  • Sow with litter: 2.4m x 1.8m with solid door (farrowing arc); block one end for warmth

Bedding:

  • Straw is the standard. Wheat straw is preferred — it lasts longer than barley or oat straw.
  • Deep litter system: build up the straw over time rather than removing it. The composting action generates warmth. Turn and top-dress rather than complete strip-outs.
  • In summer: maintain a minimum layer for comfort; full deep litter not needed.
  • In winter: increase straw provision significantly. A sow with piglets in winter needs 15–20kg of fresh straw per week.

Predator protection:

  • Foxes and dogs are the primary risk to piglets and small weaners.
  • Electric fencing around the sleeping area at night provides adequate protection in most contexts.
  • Purpose-built farrowing arcs with a solid door and latch are preferred for sows with young piglets.

Water provision per housing position: Every ark position needs a reliable water source. If moving arks across paddocks, either:

  • Use trough-based water delivery that moves with the arc, or
  • Install a simple gravity-fed water point at each paddock position from a header tank. Weaners and lactating sows are the most vulnerable to water shortage — check water in these groups twice daily.

Shade and wallows: Pigs do not sweat and are highly susceptible to heat stress above 25°C. In warm climates or during hot summers:

  • Provide a wallow (a muddy depression filled with water) in each paddock. Pigs coat themselves in mud to regulate temperature.
  • Natural shade from trees is ideal. Where absent, a shade cloth structure is inexpensive to erect.
  • Watch for sunburn on light-skinned breeds (Large White, Landrace crosses) — this is a welfare issue, not cosmetic.

Farrowing outdoors: Outdoor farrowing requires a farrowing arc placed in a sheltered position with:

  • Deep, well-banked straw bedding before the sow farrows.
  • Access to a small paddock for the sow.
  • A creep area within the arc where piglets can access supplementary heat (heat lamp) in cold weather.
  • Monitoring at least twice daily for the first week post-farrowing, more frequently in cold or wet conditions.

Outdoor farrowing mortality is higher than indoor in adverse conditions. If the weather forecast for farrowing week is below 5°C or sustained heavy rain, consider delaying or providing indoor farrowing accommodation.

Checkpoint — confirm before finalising:

  • What is the climate zone and season — what temperature extremes must the housing handle?
  • Is the system permanent or moveable — will arks need to move with the rotation?
  • Is farrowing outdoors planned, or are weaners bought in? Farrowing outdoors requires a higher housing specification than a finishing system.

Recommending a static housing structure to someone who needs a fully moveable rotation system wastes the investment.

Output:

HOUSING SPECIFICATION
System: [pasture / woodland / orchard]
Climate zone: [temperate / mediterranean / cold]
Stock: [number and category — weaners, finishers, sows, etc.]

ARK SPECIFICATION
Type: [standard ark / farrowing arc / timber shelter]
Size: [dimensions]
Number required: [number]
Material: [corrugated metal / timber]
Approximate cost: [estimate if known]

BEDDING
Type: [wheat straw / deep litter]
Quantity: [kg per week for the group]
Management: [top-dress weekly / full change monthly / other]

WATER PROVISION
Method: [mobile trough / fixed point / header tank]
Capacity needed: [litres per day for group]

SHADE / WALLOW
Required: [yes / no — reason]
Type: [tree shade / shade cloth / wallow location]

WINTER PROVISIONS
Additional straw: [yes / amount increase]
Windbreak: [required / existing / to install]
Farrowing in cold: [indoor provision / monitoring protocol]

Next steps:

  • Run rotational-management (within this skill) — ark positions need to map onto the paddock rotation.
  • /s4ag-fencing — shelter alone is insufficient; each paddock position needs appropriate fencing to contain pigs.
  • /s4ag-finance — cost the housing and infrastructure before the first pig arrives; capital costs are front-loaded in this enterprise.

Health Basics

Identifies and addresses the most common health problems in outdoor pig systems — worms, mange, foot problems, and respiratory disease.

This sub-tool covers prevention-first health management for common conditions. It does not replace veterinary advice. Any pig showing severe lethargy, high fever, neurological signs, sudden death, or suspected notifiable disease (Foot and Mouth, African Swine Fever, Classical Swine Fever) requires immediate veterinary contact and, in the UK and EU, a legal duty to report to the relevant authority.

Prevention first — the healthy outdoor pig: Most health problems in outdoor pigs have a nutritional or management cause. Before reaching for treatment, ask:

  • Is the pig at the correct stocking density, or is it stressed by overcrowding?
  • Is the pig receiving adequate nutrition for its stage?
  • Is the pasture rotation being maintained, or is the parasite cycle building up from continuous use of the same ground?

The most common health issues:

Worms (Internal Parasites)

The primary internal parasites in outdoor pigs are Ascaris suum (large roundworm), Oesophagostomum dentatum (nodular worm), and Trichuris suis (whipworm). Unlike ruminants, pigs do not develop strong immunity to roundworm — infection builds if the same ground is used continuously.

Risk factors:

  • Same paddocks used for multiple years without rest.
  • High pig density.
  • Wet, warm conditions.

Signs:

  • Poor growth rate in weaners and growers.
  • Pot-bellied appearance in young pigs.
  • Coughing in severe Ascaris infection (larval migration through lungs).
  • Diarrhoea or loose faeces in Oesophagostomum infection.

Diagnosis: Faecal egg count (FEC) — send fresh faecal samples to a vet lab. This should be routine at least twice per year, or when growth rates are unexpectedly poor.

Treatment: Macrocyclic lactones (ivermectin, doramectin) or benzimidazoles (fenbendazole, flubendazole) are effective. Dose according to the product datasheet; treat the group, not individuals. Record all treatments (legal requirement in most jurisdictions).

Sustainable note: Long rotation intervals (12+ weeks) reduce pasture contamination significantly. Pigs moving off contaminated ground before infective-stage larvae concentrate are substantially less likely to accumulate significant worm burden. Rotation is the most effective parasite management tool available.

Mange (Sarcoptes scabiei var. suis)

Mange is the most common external parasite problem in outdoor pigs and is frequently underdiagnosed.

Signs:

  • Intense scratching, especially around the ears and neck.
  • Scaly, crusty skin around the face, ears, and body.
  • Ear-shaking, head-rubbing on fencing and posts.
  • Reduced growth rate (chronic irritation suppresses growth).

Diagnosis: Skin scraping and microscopy by a vet. In practice, a trial treatment response is often used — if the signs resolve after treatment, the diagnosis is confirmed retrospectively.

Treatment: Injectable ivermectin (1% solution) at the manufacturer's rate is the standard treatment. Two doses 14 days apart are required to catch the full egg-to-adult lifecycle. Treat all pigs in the group simultaneously. Do not reintroduce untreated pigs.

Note: Mange can be introduced by bought-in stock. Quarantine all new arrivals for a minimum of 2 weeks before mixing with the main herd.

Lameness and Foot Problems

Foot problems in outdoor pigs are most commonly caused by:

  • Hard, dry ground — cracks and abrasions on the sole.
  • Waterlogged, poached ground — softening of the hoof and bacterial foot rot.
  • Joint ill (septic arthritis) in young piglets from naval infection.
  • PRRS or other systemic disease causing joint inflammation — veterinary investigation required.

Management:

  • Hard ground: provide a damp lying area or wallow to prevent cracking.
  • Wet, poached ground: the primary prevention is paddock rotation. Pigs should not be on waterlogged ground — move to dry areas or provide board/chip bedding at entry points.
  • Foot rot: antibiotic treatment under veterinary prescription. Prevention: avoid the conditions that cause it.
  • Lameness in a single pig with a swollen joint: isolate and seek veterinary advice — joint ill in weaners requires early antibiotic treatment.

Respiratory Disease

Respiratory disease in outdoor pigs is less common than in intensive indoor systems, but conditions that concentrate pigs in shared housing during wet weather can create risk.

Common causes:

  • Enzootic pneumonia (Mycoplasma hyopneumoniae) — endemic in most pig populations; causes chronic, low-grade cough and reduced growth rate.
  • PRDC (Porcine Respiratory Disease Complex) — secondary bacteria invade lungs stressed by Mycoplasma.
  • Influenza (swine influenza A) — acute onset, herd-wide.

Signs: Persistent cough in a group of pigs, especially after weather changes or stress events. Reduced growth rate. Increased respiration rate.

Prevention: Good ventilation in housing, avoiding sudden weather stress, not overcrowding arks. In endemic herds, vaccination against Mycoplasma is available.

Treatment: Antimicrobials under veterinary prescription. Veterinary diagnosis should precede any respiratory treatment — coughing has multiple causes.

When to call the vet immediately:

  • Any pig with high fever, sudden death, or neurological signs.
  • Blister-like lesions on the snout, mouth, or feet (possible FMD — notifiable).
  • Sudden severe diarrhoea with high mortality in weaners.
  • Any condition affecting more than 10% of the herd acutely.
  • Breeding stock off feed for more than 48 hours.

Checkpoint — confirm before finalising:

  • What signs are being observed — wasting, scratching, lameness, respiratory? Confirming the presenting signs before recommending treatment avoids misdirected intervention.
  • Is this an individual pig or group-level problem? Group-level health problems usually have a management or infectious cause requiring a different response than individual cases.
  • Is any bought-in stock involved, or is this a closed herd?

Recommending treatment without understanding whether this is an individual or herd problem, or without considering quarantine history, can miss an infectious introduction or cause unnecessary antibiotic use.

Output:

PIG HEALTH ASSESSMENT
Date: [date]
Presenting signs: [what is observed]
Number affected: [individual / group / proportion of herd]

MOST LIKELY DIAGNOSIS
Primary: [condition]
Rule out: [differential]

IMMEDIATE ACTIONS
1. [action — isolation / observation / treatment / vet contact]
2. [action]

TREATMENT (if applicable)
Product: [name]
Dose: [rate — confirm with vet / product datasheet]
Route: [injection / in-feed / topical]
Withdrawal period: [days — meat and milk if applicable]

MANAGEMENT CHANGE REQUIRED
[rotation interval / stocking density / bedding / nutrition]

FOLLOW-UP
Recheck in: [days]
Vet referral if: [trigger for escalation]

RECORDS TO UPDATE
[treatment record / movement record / health register]

Next steps:

  • Run nutrition (within this skill) — poor growth, wasting, and some skin conditions are nutritional rather than parasitic; assess both together.
  • /s4ag-soil — pasture-based parasite management is most effective when rotation intervals allow biological breakdown of infective stages; healthy soil biology accelerates this.
  • /s4ag-livestock — if pigs are part of a multi-species grazing system, parasite management should be coordinated across species; cattle and sheep do not host pig-specific roundworms and can be rotated through pig paddocks to break the cycle.