Chicken and Pig Rearing
Senior 3 · Agriculture
Chicken and Pig Rearing
Lesson 3 of 4
25 min
Let's begin
Rwanda's pig herd shrank from about 1.50 million in 2022 to about 1.12 million in 2023 (MINAGRI, Annual Report 2024–2025). MINAGRI blamed high deaths from African swine fever, swine erysipelas and leptospirosis (Livestock Development Strategy, 2024). In its 2024–25 disease tests, 75 of 185 poultry samples were positive for Newcastle disease (MINAGRI, 2025). Disease, not lack of feed, is often what ruins a small poultry or pig farm. A farmer who can recognise the early signs, and who vaccinates, deworms and keeps parasites down, protects both the animals and the family's income.
Definition
Disease: any condition that stops an animal's body working normally. Infectious diseases are caused by pathogens (viruses, bacteria, protozoa, fungi) and spread between animals.
Parasite: an organism that lives on (external, e.g. mites, lice) or in (internal, e.g. worms) a host and feeds on it.
Vaccination: giving a harmless form of a pathogen so that the animal builds immunity before it meets the disease.
Zoonosis: a disease that can pass between animals and people, e.g. pork tapeworm.
Notifiable disease: a disease that must be reported to the veterinary authorities as soon as it is suspected, such as African swine fever.
A healthy chicken is alert, with a bright red comb, smooth feathers and firm droppings; a healthy pig is lively, eats eagerly, has a smooth coat, a curly tail and normal droppings. Watch for: dullness and standing apart; loss of appetite; ruffled feathers or a rough coat; diarrhoea or blood in droppings; coughing, sneezing or gasping; discharge from eyes or nose; lameness or paralysis; a sudden fall in eggs or growth; and sudden deaths.
| Disease | Cause | Main signs | Prevention and control |
|---|---|---|---|
| Newcastle disease | virus | gasping and coughing; greenish, watery diarrhoea; twisted neck, paralysis; eggs stop; many sudden deaths | vaccinate on a regular schedule (eye drops or drinking water); no cure; isolate sick birds, burn or bury the dead; report to a veterinarian |
| Gumboro (infectious bursal disease) | virus | young birds of about 3 to 6 weeks: ruffled feathers, whitish diarrhoea, trembling, deaths | vaccinate chicks; strict hygiene |
| Fowl pox | virus, spread by contact and mosquitoes | wart-like scabs on the comb, wattles and face | vaccinate; control mosquitoes |
| Coccidiosis | protozoa (Eimeria) in the gut | bloody or brown diarrhoea; huddled, ruffled young birds; deaths | keep litter dry; clean drinkers; anticoccidial drugs in feed or water as advised |
| Fowl typhoid | bacterium (Salmonella Gallinarum) | yellow-green diarrhoea, weakness, deaths in adults | buy chicks from clean hatcheries; vaccinate where advised; treatment only on a vet's prescription |
| External parasites | mites, lice, fleas, ticks | pale combs, feather loss, restlessness, fewer eggs; red mites hide in cracks by day | clean house and perches; seal cracks; dust baths of dry ash or sand; approved treatment |
| Internal parasites | roundworms, tapeworms | poor growth, diarrhoea, fewer eggs | deworm regularly; keep litter dry and clean |
| Disease | Cause | Main signs | Prevention and control |
|---|---|---|---|
| African swine fever (ASF) | virus | high fever; no appetite; red to purple skin on ears, belly and legs; bloody diarrhoea; almost all infected pigs die | no vaccine and no cure; strict biosecurity; no swill or pork scraps; buy pigs only from known healthy farms; report at once to a veterinarian |
| Swine erysipelas | bacterium (Erysipelothrix) | fever; raised, diamond-shaped red patches on the skin; lameness; abortion | vaccinate; treatment by a vet; MINAGRI began vaccinating against it in 2024–25 |
| Piglet anaemia | lack of iron | pale, weak piglets of 1 to 3 weeks, breathing fast, growing slowly | iron injection at about 3 days old |
| Mange | mites (Sarcoptes) in the skin | intense itching and rubbing; thick, crusty skin, often on the ears | treat all pigs in the pen; clean the pen |
| Lice | pig louse | itching; lice visible in skin folds | approved treatment; clean pens |
| Roundworms | Ascaris worms | poor growth, coughing, pot belly; white "milk spots" on the liver at slaughter | deworm regularly; clean, dry pens |
| Pork tapeworm (zoonosis) | Taenia solium | pigs: cysts in the muscle ("measly pork"); people: tapeworm or cysts (Figure 15) | latrines; confine pigs; meat inspection; cook pork well; treat infected people |
| Leptospirosis (zoonosis) | bacterium spread in rats' urine | abortion, weak piglets | control rats; protect feed and water |
Figure 15. The life cycle of the pork tapeworm, and how to break it.
Worked example 1: reading MINAGRI's test results
Problem. In 2024–25, MINAGRI's laboratory found Newcastle disease in 75 of 185 poultry samples, and swine erysipelas in 19 of 420 pig samples. Find each percentage positive (prevalence), and say what the poultry result suggests.
Solution.
Answer: 40.5% and 4.5%. Samples sent to a laboratory often come from sick birds, so 40.5% does not mean 40% of all Rwandan chickens are infected; but it shows that Newcastle disease is common and that regular vaccination is essential.
Worked example 2: the cost of disease in the pig herd
Problem. MINAGRI estimates Rwanda's pigs at 1,498,721 in 2022 and 1,123,075 in 2023. By how many pigs, and by what percentage, did the herd fall?
Solution.
Answer: about 376,000 fewer pigs, a fall of about one quarter in a single year, which MINAGRI linked mainly to African swine fever, swine erysipelas and leptospirosis.
Warning
Safety. (1) Never eat, sell or give away animals that died of disease; burn or bury them deeply, away from water. (2) Wear gloves and wash your hands with soap after handling sick animals, dung or carcasses: some diseases infect people. (3) Use veterinary medicines only as prescribed, and respect the withdrawal period before eggs or meat are eaten. (4) Report any sudden deaths, or pigs with fever and red ears, to the sector veterinarian at once.
Tip
Memory hook: "Viruses: vaccinate. Bacteria: vet. Parasites: clean and deworm." Virus diseases such as Newcastle disease and ASF have no cure, so prevention is everything.
Food and Agriculture Organization of the United Nations (FAO): "Family poultry production - Introduction to the sustainable control of Newcastle disease". Note how village chickens are vaccinated and why vaccination must be repeated.
Practice
Key points
Sources and credits
Written by Ganzaa: the text, the tables, Figure 15 and the worked examples.
This lesson adapts CC BY-SA material and is shared under CC BY-SA 4.0.
