Gumboro is an acute, highly contagious viral infection in chickens manifested by inflammation and subsequent atrophy of the bursa of Fabricius, various degrees of nephritis and immunosuppression. Clinically the disease is seen only in chickens older than 3 weeks.
The period of clinical symptoms and high death rate is at the age of 3 - 6 weeks.Gumboro also called infectious bursal disease( IBD) could, however, be observed as long as chickens have a functioning bursa. In chickens younger than 3 weeks, IBD could be subclinical.
The infection of the Gumboro disease is widespread in all the flocks in Egypt, where the infection is found in the grandparents the broiler breeders, the layer breeders, the commercial broilers, the commercial layers and native breeds.
Causes of infection spread
The most important reason for the spread of infection is the lack of biosecurity which is represented in the following:
- Multi-ages in one place specially in commercial layers , commercial broilers and native breeds.Stacking the poultry farms in small spaces without taking into account the distances between the farms.
- The existence of farms with different activities in the same place like broiler with layers or native breed with broiler breeders this beside the presence of some turkey ducks and geese.
- Methods of disposal of dead birds in most poultry farms in Egypt are unsafe methods, even in the farms of the grandparents, which have the most important and highest herds cost Most farms are dumping dead birds in the canals and banks and a few of these farms bury dead birds and these methods facilitate the access of wild animals such as dogs and cats to these dead birds and transport them between different farms.
- More than 70% of the domesticated birds are marketed in Egypt as live birds and are not slaughtered in their own slaughterhouses. The slaughter site is unsafe and the slaughter remains are not disposed of in safe ways.
- Attention is not paid to periods between the different flocks and this increases the density of the microbes in the farm.
- In most cases biosecurity measures are not taken with people visiting the farm.
There are groups of individuals performing the vaccination in the farms, especially the vaccination, which are applied through the injection or by wing web. These groups escape among the different farms completely freely and this facilitates the transmission of infection between the farms easily and these groups perform the process of the beak trimming during the first week or the second week which causes the flock to be exposed to early infection.
Multiple vaccination programs against this disease and many of these programs are not scientifically based and these are some examples of these programs.
Examples of programs used in commercial broilers:
1-Injection of vaxxtek in the hatchery at one day old.
2-Injection of transmune in the hatchery at one day old.
3-Injection of vaxxtek at one day old + intermediate strain one shot at 10-12 day old.
4-Injection of transmune at one day old +intermediate strain one shot at 10-12 day old.
5-Hot strain one shot at 12-14 day old.
6-Intermediate strain one shot at 12-14 day old.
7-Intermediate strain two shots the first at 10-12 day old and the second at 20-22 day old.
8-Intermediate strain at 6-8 day old and hot strain at 14-16 day old.
9-In some cases dead vaccine may be injected during the first week of age in any of the mentioned programs.
I'd like to say that most of the mentioned programs was designed by poultry farm manager himself.
Examples of programs used in commercial layers:
1-Injection of vaxxtek in the hatchery at one day old .
2-Injection of transmune in the hatchery at one day old.
3-Injection of vaxxtek in the hatchery at one day old +intermediate strain at 10-12 day old.
4-Injection of transmune in the hatchery at one day old +intermediate strain at 10-12 day old.
5-Intermediate strain three times:
The first at 10-12 day old
The second at 18-20 day old
The third at 26-28 day old
6-Intermediate strain four times:
The first at 7-10 days
The second at 14-17 day old
The third at 21-24 day old
The fourth at 28-31 day old
7-Intermediate strain at 7 day old then hot strain at 14 day old then intermediate strain at 28 day old.
8-Intermediate strain at 7 day old followed by two shots of hot strain at 14 day old and 21 day old.
9-Dead vaccine may be injected during first two weeks of age in any of the mentioned programs.
Also I'd like to repeat that most of the mentioned programs were designed by the poultry farm manager himself.
The mentioned factors besides the high level of mycotoxin in the poultry feeds keep the infection persists and circulates in the flocks.
How the disease appears?
- The disease appears in its classic form
- Disease appears suddenly and morbidity may reach 100%.
- Birds are prostrated, debilitated and dehydrated.
Mortality rates vary according to:
- Virulence of the strain.
- Immunity of the flock.
- Presence of concurrent disease.
- Presence of mycotoxins in feed.
- General management of poultry farm.
- Type of bird (layer or meat-type).
- Hemorrhages in thighs and breast muscles.
- inflammation and accumulation of urate in kidneys.
- Increased bursal size.
- Oedema with gelatinous and hemorrhagic contents in bursa.
How to face the problem
- Following biosecurity measures is the right start to control any disease.
- Follow a unified program for each area according to the type of infection.
- Conduct the required laboratory tests periodically to determine the problem in each area.
- Stop selling live poultry.
- Safe disposal of the remains and remnants of slaughtering poultry as well as dead birds.
- Implement the necessary legislation to prevent the spread of epidemic diseases.
- Establishment of breeding and slaughtering places of poultry in the desert back of governorates and determining the production density of each group.
- Conduct a comprehensive survey of all poultry production areas in Egypt to identify the cause of the disease and the development of preventive programs by specialists in the field of poultry diseases.
- Work on a future plan whose aim is to rely on factories producing Egyptian vaccines. These factories will depend on the Egyptian field isolates in the production of vaccines.
- Activating the control role on the poultry farms to ensure the implementation of the instructions and the implementation of the procedures and instructions for biosecurity.
- Vaccine companies should make the necessary awareness to the managers of poultry farms on how to use these vaccines.
- As we have seen in the vaccination programs that some managers of poultry farms use the vaccine transmune in commercial layers, although the company produced this vaccine is dedicated to commercial broiler chickens.
- Poultry farms managers should rely on veterinary diagnostic laboratories to perform accurate diagnostic procedures and not only with symptoms and anatomical changes.
- Finally, we should know that the union and cooperation of poultry workers will help overcome all the problems facing the poultry industry in Egypt.