Infectious bronchitis of chickens is a very dangerous disease, which usually results in mortality of a part of the herd and a significant decrease in egg production. Currently, IBC is detected in poultry farms, unfortunately, quite often. The main measure to combat this disease is considered preventive vaccination.
A bit of history
This disease is caused by an RNA-containing virus of the Coronaviridae family. One of the features of the causative agent of IBS is the ability to quickly mutate. This causes significant difficulties in the prevention of infectious bronchitis in poultry farms.
For the first time, the IBA causative agent virus was isolated by US scientists in 1936. According to some sources, this disease was imported into Russia in about 1946. At present, chickens in poultry farms in our country mainly suffer from two strains of the chicken infectious bronchitis virus: Massachusetts and 793B. It is from these two varieties in Russia that the largest number of immunological preparations have been developed.
Biology of the pathogen of infectious bronchitis of chickens
The Massachusetts serotype was first identified in the 40s of the last century in the United States and Europe. This strain affects mainly the respiratory organs of the bird. As a result, chickens develop acute respiratory infections, which can lead to their death. 793B is the cause of high mortality mainly in broilers. This strain can affect both the respiratory and urogenital systems of birds.
Both of these varieties of the virus differ:
Resistance to adverse environmental factors. In drinking water, the IBC virus is able, for example, to survive up to 11 hours.
Resistance to acidic environments. In alkali, IBA strains usually die quickly.
Relative UV resistance. Under its influence, the virus dies in most cases in a day.
At elevated temperatures, the IBC virus usually dies quickly enough. For example, at 50 ° C this happens in 10 minutes.
What is the danger of the disease?
Chicks and adult birds can become infected with the IBC virus. Most often, young people suffer from this ailment. In most cases, the respiratory system is affected in chickens. In adult chickens and young females with IHD, the reproductive system usually suffers. In some cases, chickens may even stop flying at all.
The danger of infectious bronchitis, in addition to reducing productivity, lies in the high degree of poultry mortality. Losses during an epidemic in an economy often exceed 35%. This applies to both young and adult birds.
In the event that the infection gets on the farm, it will be very difficult to remove it. Even recovered chickens for several months remain carriers of the virus and can transmit it to other individuals. In most cases, IBC in a dysfunctional farm cannot be cured of the livestock, but, unfortunately, it becomes chronic.
Causes of the spread of infections
This disease is transmitted mainly from individual to individual. That is, an IBI epidemic on the farm can break out, for example, after buying new chickens or youngsters. Sometimes a hatching egg becomes the cause of an outbreak of chicken infectious bronchitis on the farm. Bred from such material obtained from sick laying hens, chickens in most cases also turn out to be infected.
How is the infection transmitted?
Routes of infection in healthy chickens with infectious bronchitis include the following:
Aerogenic In this case, the virus is secreted from the nostrils and beak of a sick bird and spreads by air current.
Contact. In this way, the virus is often transmitted in those farms where there is a large crowding of chickens.
Oral fecal. Chickens, as you know, sometimes eat their own litter. In this case, infection can also occur very easily.
Sexually. A rooster can transmit the disease to the chicken when coated.
The danger of IBC, therefore, lies, among other things, in a large number of possible pathways of infection.
Flow patterns
Both acute and chronic infectious bronchitis can develop in chickens. Forms of the course in chickens, these differ mainly only in the severity of symptoms. In acute disease, the latter manifest themselves brighter. In the chronic form, only difficulty breathing in the bird and discharge from the nose are noticeable.
Most often, chickens on the farm die, of course, from acute IBC. However, with chronic mortality rates can be very large. In some cases, farmers lose up to 30% of the herd in this form of the disease.
Symptoms of the disease with damage to the respiratory system
The incubation period in the IBC virus can last from 36 hours to 10 days. In most cases, the first signs of this disease become noticeable a week after infection. In chickens, the following symptoms of chicken infectious bronchitis are usually observed:
cough;
labored breathing;
weight loss;
neck curvature;
conjunctivitis.
The wings of sick chickens usually fall strongly down. The chicks themselves look weakened and inactive.
Symptoms in an Adult Bird
In such chickens, the IBC virus infects both the respiratory and reproductive systems. Symptoms in an adult bird include the following:
Chickens with infectious bronchitis look lethargic and weakened. The shell of the eggs laid by them in most cases is soft.
Inexperienced farmers of IBC in chickens, unfortunately, usually do not immediately notice. The symptoms of this disease are mainly respiratory. And therefore, beginners often take infectious bronchitis for a common cold.
With a prolonged course of IBC, chickens, among other things, are affected and cease to effectively perform their kidney functions. The result is severe diarrhea. If the chicken has already passed the disease to this stage, in any case it will not be possible to save it.
Pathological changes
Chickens die in IBS, as already mentioned, quite often. Moreover, the following changes are found in the corpses of such a bird:
numerous hemorrhages in the trachea and bronchi;
often - the presence of serous and catarrhal exudate (with inflammation);
underdeveloped ovaries with signs of hemorrhage in an adult bird;
atrophy of egg follicles;
cysts in the ovaries.
In the event that the chicken infectious bronchitis proceeded in a severe form during pathological studies, swelling of the mucous membranes and epithelial infiltration can also be detected. The kidneys of such a bird in most cases are increased in volume and are distinguished by the diversity of the pattern. In the urinary canals of chickens who died from IBC, urates are often found.
How is the diagnosis carried out?
To confuse the IBC of chickens with the common cold is thus quite easy. For accurate diagnosis of infectious bronchitis, veterinarians therefore conduct laboratory tests. For this purpose, swabs from the trachea and larynx are taken from the bird. Further, such material is checked for the presence of a virus.
In some cases, serological tests may also be performed during the diagnosis. At the same time, veterinarians:
If poultry is suspected of having infectious bronchitis, blood is taken for analysis every two weeks, among other things. Research in this case, of course, is also carried out in order to identify the pathogen strain.
Treatment of chicken infectious bronchitis
When identifying IBC on a farm, first of all, a healthy bird should be separated from a sick one. Actually, for the treatment of hens, the method of general antiviral therapy is usually used. In this case, drugs such as:
Blue iodine for the treatment of infectious bronchitis of chickens is most often used in the amount of 0.2 or 0.5 ml per day per head. At the same time, it is allowed to give such medicine to the bird both in pure form - with food, and diluted with water.
"Anfluron" is also a good answer to the question of how to treat infectious bronchitis of hens. This drug is used for such a disease, usually in an amount of 0.5-1 ml per day. The course of treatment with this tool in this case in most cases is a week. Such a preparation is given orally to chickens in a dry form or intramuscular injections are given.
Appropriate measures should be taken on a farm against IBS, of course, immediately after its first symptoms have been noticed. Both treatment of infectious bronchitis of chickens and its prevention, however, will be ineffective if the bird is kept in dirty, unventilated rooms. In the chicken coop, when infection is detected, good ventilation should be provided immediately. Also, the house must be thoroughly cleaned.
Further, the chicken coop is treated with blue iodine without fail. This substance is pre-diluted with water, and then the resulting solution is sprayed in the house. The concentration of iodine in the air in the chicken coop should ultimately be 10 mg / m 3 .
Alternative methods of treatment
Chickens become infected with infectious bronchitis, of course, not only on large farms, but also on personal farms. Summer residents for the treatment of IBS can use various kinds of folk methods.
In the courtyards of this disease, chickens are trying to give more greens - nettles, carrot tops, etc. Also, more vitamin and mineral premixes are added to the poultry mixes.
Disease prevention
Unfortunately, the treatment of infectious bronchitis in chickens is often ineffective. IB viruses are survivable and transmitted in many ways. Therefore, it is important to periodically conduct various activities at the poultry farm aimed at preventing the spread of this disease.
The most effective preventive measure against IBS is, of course, vaccinations. The main types of vaccines against infectious bronchitis of chickens, there are only two:
Live vaccine. Such drugs are commonly used to vaccinate chickens. Means of this type create early protection of young animals. Immunity to most types of virus in chickens when using such drugs is usually developed after 2 weeks. The main disadvantage of this type of vaccine is the risk of mutation of the strains contained in them to wild species.
Inactivated vaccine. Preparations of this variety are mainly used for youngsters and the parent herd. When such a vaccine is used, maternal antibodies begin to be produced in laying hens.
Before using an inactivated vaccine for infectious bronchitis, chickens are first vaccinated with live vaccines. Moreover, such a procedure is carried out for at least 4-5 weeks. Using this technique allows you to provide protection against infection in 95% of cases.
How to prevent an outbreak of infection on the farm?
In addition to vaccination, on farms to prevent an epidemic of IBS, it is also supposed to carry out such measures:
hatching egg disinfection;
monitoring the characteristics of indoor air;
distribution of poultry by age.
Of course, it is only necessary to purchase feed and new young animals for the farm in neighboring farms that are prosperous in terms of infectious bronchitis. The same goes for hatching eggs.
Certain security measures in terms of the spread of the epidemic, of course, must be followed by the owners of those farms in which IBS has already been identified. Such farms are prohibited first of all from exporting and selling live birds, embryos and an hatching egg. Moving chickens from room to room in such factories is also not allowed. Sick semen for insemination of chickens should not be taken from sick males in such farms.