भाषा:

As nights turn cold in October and November, many poultry farmers hear it first: a rattling, gurgling sound from the chicks at night, sneezing all over the shed, and birds huddling near the brooder. In layer farms the first sign is often different: eggs suddenly drop, and the ones that come are thin-shelled, rough or misshapen. One common cause of both is infectious bronchitis (IB), a fast-spreading viral disease of chickens. IB has no medicine that kills the virus, so prevention, early recognition and good supportive care decide how much you lose. Here is how to spot it, how vaccination works, and what to do when it hits.

What is infectious bronchitis?

IB is caused by a coronavirus that affects only chickens. It is not the same virus as human COVID and does not infect people. The virus attacks the lining of the windpipe and airways first, and some strains also damage the kidneys or the egg-laying tract (oviduct).

  • It spreads very fast through the air, from bird to bird, and on shoes, crates, egg trays, vehicles and people. A whole shed can show signs within 1–2 days.
  • All ages are affected. Young chicks suffer most with breathing trouble; in laying hens the bigger loss is eggs.
  • On its own IB kills few birds. The real losses come when bacteria such as E. coli and Mycoplasma enter the damaged airways. This mixed infection (often called CRD complex) is what causes high mortality, poor weight and heavy culls in broilers.

Why IB is worse in winter

In winter, farmers close curtains to keep the shed warm. That is right for the chicks, but with too little fresh air, ammonia from wet litter and dust build up. Ammonia damages the hair-like cells that keep the airways clean, so the virus and bacteria settle easily. Cold draughts at bird level, large temperature swings between day and night, and crowding all add stress. If your litter is getting wet and smelly, read our guide on wet litter in broilers in winter first, and keep a minimum fresh-air flow as explained in poultry ventilation management.

Signs of IB: broilers and chicks

  • Rattling or gurgling sound (rales), best heard at night when the shed is quiet
  • Sneezing, head shaking, gasping with an open beak and stretched neck
  • Wet eyes, watery nasal discharge, sometimes slightly swollen face
  • Chicks huddle near the heat, eat and drink less, and growth slows
  • Kidney form: some strains damage the kidneys. Birds look dull and dehydrated, droppings are wet with a lot of white urates, and dead birds show swollen, pale kidneys
  • Uneven flock, poor FCR, and more culls and condemnations at the end of the batch

For other causes of chick losses in the first days, see early chick mortality.

Signs of IB: laying hens

  • Sudden egg drop, often over a few days, and it can take weeks to come back
  • Thin, soft, rough or wrinkled shells, misshapen eggs and shell-less eggs
  • Lighter shell colour in brown eggs
  • Watery egg white: break an egg on a plate, and the thick white spreads out like water
  • Mild breathing signs that many farmers miss
  • False layers: if pullets get IB in the first 2–3 weeks of life, the oviduct can be damaged for good. These birds look healthy and have a red comb but never lay properly. This is one big reason to vaccinate chicks on time.

More on layer nutrition and production in our layer poultry farming guide.

IB or something else? Do not guess

Several winter diseases look alike. Rough guide only; a vet and a lab test (post-mortem, PCR or blood test) are needed to be sure:

DiseaseWhat points to it
Infectious bronchitis (IB)Spreads through the whole shed in 1–2 days, rattling sound, egg drop with poor shells and watery whites, wet droppings with urates in kidney form
Ranikhet / Newcastle disease (ND)Much higher deaths, greenish droppings, twisted neck, paralysis, bleeding spots in the gut
CRD (Mycoplasma)Slower spread over weeks, long-lasting rattle, foamy eyes, often follows stress or IB
Infectious coryzaSwollen face and wattles, sticky bad-smelling nasal discharge
Avian influenzaSudden heavy deaths, blue comb and wattles, swollen head. Report to the veterinary department at once

Read more on respiratory diseases and CRD in poultry and Ranikhet disease.

1. Prevention starts with vaccination

Since no medicine kills the IB virus, vaccination is the main protection.

  • Chicks: IB live vaccine is usually given in the first days of life (at the hatchery or on the farm), often combined with ND vaccine, with a booster later. Ask your hatchery what was already given to your chicks.
  • Layers and breeders: live vaccines during rearing, then a killed (oil) vaccine before the start of lay, gives longer protection to the egg tract.
  • Follow the schedule from your vet or vaccine company for your area, because the strains in each region differ. Our broiler 42 days medicine schedule and poultry vaccination guide show where IB fits.
  • Vaccine handling matters as much as the vaccine. Keep it cold, use clean water without chlorine or sanitizer on vaccination day, give it in the morning, and make sure every bird drinks it within 1–2 hours. Use the full bottle once opened.
  • Some birds sneeze for a few days after a live IB vaccine. That is a normal vaccine reaction. Good air quality keeps it mild.

2. Shed management in cold weather

  • Keep chicks warm at their level, but give a minimum fresh-air flow every hour, even on cold nights. If your eyes sting or you smell ammonia when you enter, it is too much. Our winter broiler brooding guide covers temperature by age.
  • Stop cold draughts at bird level. Open curtains from the top, not the bottom.
  • Keep the litter dry and loose. Remove wet patches near drinkers.
  • Do not overcrowd. Follow all-in all-out, and clean and disinfect between batches.
  • Biosecurity: separate footwear for each shed, limit visitors, and keep egg trays, crates and vehicles from other farms away from the sheds.
  • Give clean, fresh drinking water. See water quality for poultry.

3. If IB hits: supportive care

Once birds are sick, the aim is to keep them eating and drinking, cut stress, and stop secondary infections from taking over.

  • Raise brooding temperature a little for young chicks, but do not shut the shed completely.
  • Keep feed and water easy to reach. Sick birds will not walk far.
  • In the kidney form, make sure clean water is always available. Ask your vet about lowering protein or calcium in the feed for a short time.
  • Give herbal supportive care with antioxidants and vitamins, early in the outbreak:
Virocon herbal supportive care for viral outbreaks in poultry by IMN Pyrophos

Viral outbreak support

Virocon

Phytobiotic support with herbal antioxidants, capsicum, garlic and allium extracts, anti-inflammatory herbs, vitamins E and C and probiotics. Supportive care in viral outbreaks such as IB, ND, IBD, IBH, LPAI, CIA and Marek’s, and helps reduce mortality.

Dose: 1 g per 5 kg body weight or 3 g per litre of water. Give in the morning in fresh water so the birds finish it within 3–4 hours.

500 g ₹579MRP ₹950

Virocon is supportive care, not a vaccine and not a cure. It works best alongside vaccination and good shed management. Product details: Virocon.

  • Antibiotics do not kill the IB virus. If E. coli or Mycoplasma come in on top of IB (rising deaths, cloudy air sacs, fibrin on the heart and liver at post-mortem), your vet may prescribe a suitable antibiotic. Do not start antibiotics on guesswork, and keep withdrawal periods before sale.
  • Do not vaccinate a flock that is already sick unless your vet advises it.

4. Immunity: around vaccination and during an outbreak

IB spreads fast in winter, and stressed birds with weak immunity suffer the most. Strong immunity around vaccination helps the vaccine “take”, and during an outbreak it helps the flock fight back, along with Virocon and your vet’s advice.

Nexamune immune booster for poultry by IMN Pyrophos

Immune booster

Nexamune

Vitamin E, selenium, amla, tulsi and ashwagandha extracts, vitamin C, vitamin D and niacin: an antioxidant shield that supports immunity. Supports the immune system in outbreaks like IB, ND, Gumboro, IBH and LPAI, reduces the severity of CRD and other respiratory problems, and helps reduce the chance of vaccination failure.

Dose: 1 ml per litre of water or 15 ml per 100 birds for immunity and stress; 2 ml per litre of water before and after vaccination; 25–30 ml per 100 birds during viral outbreaks.

1 L ₹644MRP ₹1,190

Product details: Nexamune. For layers, egg numbers and shell quality usually improve over several weeks after IB; eggs from birds damaged as young chicks may never fully recover, so watch for false layers and plan culling with your vet.

When to call the vet urgently

Respiratory signs with rising deaths are an emergency. Call your vet and send dead birds for post-mortem the same day. Several winter diseases, including Ranikhet and bird flu, start with breathing signs, and only a test can tell them apart.

Call the vet straight away if:

  • Daily deaths keep rising for 2 days or more
  • You see twisted necks, paralysis or green droppings (think of Ranikhet)
  • Many birds die suddenly with blue combs or swollen heads (report possible bird flu to the veterinary department)
  • Egg production falls sharply in a laying flock
  • Breathing signs last more than a week or come back after the batch looked better

Do not give medicines or injections on guesswork. Diagnosis first, then treatment.

IB winter checklist

WhenWhat to do
Before chicks arriveClean and disinfected shed, dry litter, ask the hatchery which vaccines were given
First 2–3 weeksIB vaccine on schedule, warm at bird level, minimum fresh air every hour
Every nightListen for rattling sounds, check for ammonia smell and cold draughts
LayersKilled vaccine before lay, track daily egg count and shell quality
OutbreakVet and post-mortem first, herbal supportive care, no antibiotics on guesswork
ImmunityBoost immunity around vaccination and in outbreaks; watch egg numbers and false layers
Breathing sounds or an egg drop in your flock? Send a short video of the birds, the age, the bird count and your vaccination record on WhatsApp +91 98715 84101. Dr. Ibne Ali’s team will tell you what to check first. Ask on WhatsApp

Also read: poultry respiratory diseases · winter broiler brooding · wet litter in winter · poultry ventilation · broiler 42 days medicine schedule · water quality for poultry · IMN products

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