Farm Sanitation and Biosecurity

22 min

Let's begin

In April 2021 a Rwandan photographer caught a familiar scene: a man cycling to market with live chickens tied to his bicycle (photo below). Every time birds or pigs move between farms and markets, and every time a visitor walks from one pen to another, diseases such as Newcastle disease and African swine fever can travel too. Most of these diseases have no cure. What protects a farm is a set of everyday habits: sanitation, keeping the farm clean, and biosecurity, keeping disease out and stopping it from spreading.

Definition

Farm sanitation: keeping animal houses, equipment, feed, water and surroundings clean, so that pathogens and parasites cannot build up.

Biosecurity: all the measures that keep diseases out of a farm and stop them spreading within it or to other farms.

Disinfectant: a chemical that kills pathogens on surfaces, such as a chlorine bleach solution or a commercial farm disinfectant. It works only on surfaces that are already clean.

Isolation (quarantine): keeping new or sick animals apart from the rest, for long enough to see whether they carry disease.

All-in, all-out: putting a whole batch of animals of the same age into a house together and removing them all together, so the house can be emptied, cleaned and rested between batches.

1. Farm sanitation rules

Keep houses clean and dry. Remove pig dung every day; turn poultry litter and replace wet patches at once.
Clean feeders and drinkers daily; give clean water and fresh feed; store feed dry and off the floor, where rats cannot reach it.
Footbath at every door, refilled with fresh disinfectant whenever it is dirty or diluted by rain.
Control visitors. Allow only people who need to enter; give them clean boots or overalls; never go from another farm's animals to yours without washing and changing.
Isolate new animals for two to four weeks before they join the herd or flock; buy only from known healthy farms and certified hatcheries.
Isolate sick animals at once and call the veterinarian; report sudden deaths.
All-in, all-out: clean, disinfect and rest each house between batches.
Dispose of dead animals safely: burn them, or bury them at least 1 m deep under lime, away from water. Never eat, sell or give them away, and never throw them in rivers or bushes.
Manage manure in a covered pit, compost heap or biogas digester, downhill and away from homes and water.
Control vermin: rats, flies, wild birds and stray dogs carry disease; use mesh, keep the grass short and remove rubbish.
Vaccinate and deworm on schedule, and keep records of vaccinations, treatments, deaths and production.
Keep species and ages apart: chickens and pigs in separate houses; young animals away from older ones.
Personal hygiene: wash hands with soap after work; wear work clothes only on the farm; do not eat or drink in animal houses.

Figure 16. Layout of a biosecure small farm.

2. Cleaning and disinfecting a house between batches

Remove all the animals (all-out) and the feeders, drinkers, nest boxes and other movable equipment.
Remove all litter and dung, and take it to the manure pit or compost.
Dry-clean: sweep and scrape the floor, walls, roof beams and mesh, and brush off cobwebs and dust.
Wash every surface and all equipment with water and detergent, scrubbing off dirt; disinfectants do not work through dirt.
Rinse and let dry.
Disinfect: apply disinfectant at the dilution on the label, and leave it for the contact time stated. Lime wash on walls is a cheap extra.
Rest the house, empty and closed, for about two weeks; repair holes and cracks.
Put in fresh litter and clean equipment, then bring in the new batch (all-in).

An empty, clean poultry shed with a concrete floor and an insulated roof in India. An empty house like this, between batches, is the moment to wash, disinfect and rest it before the next birds arrive. Photo: Hilnik1, <a href="https://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA 4.0</a>, via Wikimedia Commons

Worked example 1: mixing a footbath

Problem. A disinfectant label says: "Use 20 mL of concentrate per litre of water." The footbath holds 15 L. How much concentrate is needed?

Solution. $20\,\mathrm{mL\,L^{-1}} \times 15\,\mathrm{L} = 300\,\mathrm{mL}$

Answer: 300 mL of concentrate in 15 L of water. Too weak a mix does not kill pathogens; too strong wastes money and can burn skin. Wear gloves when mixing.

Worked example 2: how many broiler batches a year?

Problem. A farmer rears broilers for 6 weeks, then needs 2 weeks to clean, disinfect and rest the house. How many complete batches can he raise in a year (52 weeks)?

Solution.

Each cycle takes $6 + 2 = 8$ weeks.
Cycles per year $= \frac{52}{8} = 6.5$ , so 6 complete batches.

Answer: 6 batches. Cutting the rest period to squeeze in a seventh batch is tempting, but diseases then pass from one batch to the next, and losses usually cost more than the extra batch earns.

Warning

Safety with disinfectants and dead animals. Read the label; wear gloves, boots and eye protection when mixing; never mix chlorine bleach with other chemicals or acids (poisonous gas); store disinfectants locked away from children, feed and water. Handle carcasses with gloves and wash your hands afterwards: some animal diseases infect people.

Tip

Memory hook: "Keep it out, keep it in, keep it clean." Keep disease out (fence, footbath, isolation, visitor control), keep it in if it arrives (isolate, report, safe disposal), and keep everything clean (daily sanitation, all-in all-out).

Food and Agriculture Organization of the United Nations (FAO): "Biosecurity is key to stop African Swine Fever - Be a Champion Farmer!". List the biosecurity habits shown and match each to a rule in this lesson.

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Practice

Distinguish between farm sanitation and biosecurity.
Give eight farm sanitation rules for a chicken or pig farm.
Why must new animals be isolated before they join the herd or flock, and for how long?
List, in order, the steps for cleaning and disinfecting a poultry house between batches.
Why must a surface be washed before a disinfectant is applied?
A disinfectant is diluted 1 part in 200 parts of solution. How many millilitres of concentrate are needed for 25 L of footbath solution?
State three correct ways and two wrong ways of disposing of a pig that died of disease.
Evaluate this farm: the pigsty is beside the family's water spring; visitors walk freely into the pens; the farmer buys piglets at the market and puts them straight in with his own pigs; dead pigs are thrown into the bush. Recommend improvements.

Show answersHide answers

Sanitation is keeping houses, equipment, feed, water and surroundings clean; biosecurity is the wider set of measures that keep disease out of a farm and stop it spreading within and beyond it (sanitation is one part of biosecurity).
Any eight of the thirteen rules: clean, dry houses; daily cleaning of feeders and drinkers; footbaths; visitor control; isolation of new animals; isolation of sick animals; all-in all-out; safe disposal of dead animals; manure management; vermin control; vaccination, deworming and records; species and ages kept apart; personal hygiene.
They may carry diseases or parasites without showing signs at first; isolation for two to four weeks lets signs appear before they can infect the rest.
Remove animals and equipment; remove litter and dung; dry-clean; wash with detergent; rinse and dry; disinfect at the right dilution and contact time; rest the house for about two weeks; fresh litter, clean equipment, new batch.
Dirt and dung shield pathogens and use up the disinfectant, so it cannot kill them.
$\frac{25\,000\,\mathrm{mL}}{200} = 125\,\mathrm{mL}$ .
Correct: burn it; bury it at least 1 m deep under lime, away from water; call the veterinarian and follow instructions (especially if ASF is suspected). Wrong: eating, selling or giving it away; throwing it into a river or the bush.
Poor biosecurity throughout: manure and run-off can pollute the spring; visitors carry disease between pens; market piglets may bring ASF or mange straight into the herd; carcasses in the bush spread disease to wild animals, dogs and neighbours. Improvements: move the sty downhill and away from the spring; fence the farm with one gate and a footbath; limit visitors and give them clean boots; isolate new piglets for two to four weeks and buy from known healthy farms; burn or bury dead pigs deeply and report deaths to the veterinarian.

Key points

Biosecurity keeps disease out, contains it if it comes and keeps the farm clean; most poultry and pig virus diseases cannot be cured.
Key rules: clean, dry houses; clean feeders and water; footbaths; few visitors; isolate new and sick animals; all-in all-out; safe disposal of carcasses and manure; vermin control; vaccination, deworming and records.
Clean before you disinfect; use the label dilution and contact time; rest houses between batches.

11. Farm sanitation rules

22. Cleaning and disinfecting a house between batches

1. Farm sanitation rules

2. Cleaning and disinfecting a house between batches