Infectious bronchitis (ib), Biology

Assignment Help:

Infectious bronchitis (IB)

Infectious bronchitis is a highly contagious respiratory disease of poultry, caused by a virus belonging to the family Coronaviridae. Its existence in India is known since

1969. The disease spreads rapidly through aerosol and indirect transmission through contaminated feed, water troughs and other fomites can also occur. Transovarian transmission does not occur. Birds at all stages are susceptible but chicks below 4 weeks of age are severely affected.

Symptoms and lesions: Clinically the birds show depression, coughing, gasping, tracheal rales, sneezing and discharges from the eyes and nostrils, and occasionally swollen sinuses. Sometimes the disease may go unnoticed. Early infection of the chicks may lead to oviduct damage that result in laying failure. Infection of laying flock may be responsible for lowered egg production and eggs laid may be misshapen, rough and soft shelled. These characters of eggs alongwith poor internal quality and very low hatchability are the strong indications for suspicion of IB infection. In young chicks mortality may go upto 25%. In the renal form of the disease mortality may occur in broilers. The course of the disease is up to 3 weeks. Recovered birds may act as carrier for a variable period up to 1 month. On PM examination, congestion of lungs and the cloudy air sacs may be seen. Excess mucus and catarrhal exudates in the trachea and lungs, caseous plugs may be seen in the lower trachea of chick. When oviduct is involved, it may be regressed, absent or non-patented or cystic vestiges are seen. When nephropathic strains are involved, the kidney may be swollen and pale with tubules and ureters distended with uretic deposits.

Diagnosis: This is based on clinical symptoms and gross lesions. Virus isolation can be made from trachea, air sacs, caecal tonsils, oviduct and kidney. The virus isolation attempts in chicken embryos invariably show characteristic dwarfing and stunting of the embryos. Demonstration of viral antigens by fluorescent antibody test and intra- tracheal inoculation of susceptible chicks with original samples or first passage culture fluids are also helpful. Demonstration of antibodies in recovered bird by ELISA, hemagglutination inhibition and agar gel diffusion is used for confirmatory diagnosis.

Prevention and control: Proper hygiene and good management are necessary. Live vaccines are used in broilers and for initial vaccination of breeders and layers. Inactivated oil adjuvanted vaccines are primarily used at the point of lay in breeders and layers. Best protection with inactivated vaccine can be obtained only if it is given after priming the birds with live vaccines. It is necessary that the vaccine should contain the serotype prevalent in the field. Indiscriminate use of the vaccine has to be discouraged as this may lead to dissemination of variant strains. Though aerosol vaccination is said to be more effective, this method should be adopted only in flocks having a base immunity to avoid penetration of the vaccine virus deep into the lungs.


Related Discussions:- Infectious bronchitis (ib)

Which term describes first step in production of urine, In studies of human...

In studies of human body, which of the below terms is used to describe the first step in production of urine? Is it: a) Tubular reabsorption b) Tubular secretion c) Glome

How are animals classified according to the germ layers, Q. How are animals...

Q. How are animals classified according to the germ layers present in their embryonic development? Cnidarians are diploblastic, that is they present only ectoderm and endoderm.

Functions of lysosomes, FUNCTIONS (1 )      Intracellular digestion -...

FUNCTIONS (1 )      Intracellular digestion - Individual cells may obtain food through phagocytosis. The same is digested with the help of lysosomes. It is of two types:-

Evolution, Evolution can be explained as follows  1) The change in the ...

Evolution can be explained as follows  1) The change in the life over time by adaptation, over-reproduction, variation and differential survival/reproduction, a procedure refer

Explain about cold preservation - methods of food processing, Explain about...

Explain about Cold Preservation - methods of food processing? The metabolism of a living tissue is a function of the temperature of the environment. Low temperatures are used t

Tumours of kidney - wilm''s tomour, Tumours of kidney - Wilm's Tomour ...

Tumours of kidney - Wilm's Tomour So  far you have learnt about the disorders in glomerular dysfunctioning, now you will learn about the tumours in kidney the wilm's  tumour.

Explain factors that alter the speed of enzymatic recations, What are the m...

What are the main factors that alter the speed of enzymatic reactions? The major factors that change the speed of enzymatic reactions are temperature, pH and substrate concentr

Define the glucose tolerance test, Q. Define the Glucose Tolerance Test? ...

Q. Define the Glucose Tolerance Test? In Glucose Tolerance Test (GTT) if the blood sample is to be taken in the morning, patient is advised to follow fasting instructions i.e.

Explain about the term- chroma, Explain about the term- Chroma Chroma is...

Explain about the term- Chroma Chroma is the relative purity or strength of the spectral colour and its numerical value extend from (/0) for neutral colours to (/8) for the stro

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd