Some Requirements for Introducing New Chickens to Farms
Dr. Milad Ibrahim Arabi
12/ 7/ 2025
When introducing new chickens to farms, and when the epidemic situation in the area is very high in terms of adenovirus infection, the veterinarian should inquire about the project from which the chickens came. If the flock has been vaccinated against E8b or C4 adenovirus, the offspring should be vaccinated between the ages of one and five days. If the flock has been infected with adenovirus and recovered, the offspring should be vaccinated between the ages of 14 and 5 days.
This is because vaccination with inactivated oil vaccines, such as SC, takes an incorrect approach when the virus enters the chicken’s body. Therefore, the immune response is artificial, meaning it is man-made, rather than natural. This means that the immune cells are fully conscious and have sufficient time to multiply and activate. Therefore, they will have enough time to produce antibodies because the virus is dead and cannot replicate in the chicken’s body. Therefore, antibodies will be produced by the killed virus in a specific amount for a period not exceeding 10 days of the chicken’s life.
As for natural infection, i.e., the introduction of a natural virus through the respiratory or digestive tract of the chicken, the immune system will not be ready, nor will the immune cells. The immune system will be generally stimulated. If the cells survive, they will produce numerous antibodies due to the virus replicating at the site of entry. Therefore, the immune cells will continue to produce antibodies continuously for a long period, that is, after the chicken recovers from the infection. Consequently, the antibodies are transmitted via MDA to the offspring in very large quantities, which may extend beyond the age of the offspring to more than 24 days.
Recommendations:
1. If chickens are vaccinated with adenovirus, they should be vaccinated with the adenovirus vaccine between the ages of 1 and 5 days.
2. If chickens are infected with adenovirus and recover, they should be vaccinated between the ages of 14 days due to the interaction that will occur between MDA and the vaccine. Therefore, we always find infection in local chickens, knowing that they are vaccinated with the dead oil vaccine, because the eggs come from chickens infected with the disease and are not vaccinated.
