It is vitally important to ensure that disease is not spread between chickens based on different sites. The practice that is in place to do this is known as bio-security. It is normally through the feeding process or cleaning of their feathers that they are most at risk of picking up infections. Once already wounded, additional infections can set in and at this stage certain internal organs can become damaged.
Spreading the Disease
Having spread throughout the body, the infection will enter into the bowel and leave the chicken’s body in the form of droppings. Disease can also be passed on through exhalation or on occasions, through cuts and wounds. As soon as other chickens mix with the infected birds, then they will also become infected. The problem is that the agents that have become infected do not die once they leave the body of the chicken. Coccidia and worm eggs can live for a matter of months outside the chicken, but fortunately others cannot withstand elements such as sunlight. Heat and disinfectant can also remove them leaving other chickens safe from picking up the illness.
How Disease is spread
There is still the risk of other chickens becoming infected even when the agent can be destroyed, but here there will have to be direct contact. When it is via agents that can survive, the choices are wider. It can be through animals, humans – chicken droppings can stick to shoes and be passed from site to site – and even certain materials. The infection may live on pieces of eggshell, or even on the body of a dead chicken.
How the Infection Develops
It will take sometime after the chicken has become infected before the signs of the illness emerge. This is called the incubation period and it is here that the organisms carrying the infection will multiply inside the bird. They are weakening the bird and also causing them to breathe out disease and excrete it in their droppings. This is a major problem as no one knows that the bird is ill or infecting others so no action is being taken. A major issue here is a hen passing the disease directly to its young. When this happens, commercial enterprises begin to suffer financially.
When it comes to the likes of Newcastle disease it takes more than flock management and good production practices to control them. Such a contagious disease can lead to a high mortality rate and as the impact can be so great to the industry, they are classed as notifiable diseases. The authorities need to be informed as well as veterinary departments
Most Common Bio-security Measures
- Avoidance of locations near to the infected farms – at least 500m is recommended.
- Take note of the wind direction in order to protect against airborne infection.
- Alteration to the rearing cycle can prevent some passing on of the infection.
- Careful disposal of litter.
- Keep the infected site as secure as possible. If personnel are not moving between sites, it will be easier to contain.