The Diagnosty And Control Of The Kidney Type Infectious Bronchitis Virus Of The Chicken With White Feather

With various serological types,The Infective Bronchitis varies frequently, leading to the obvious discrepancy on clinical feature. Local epidemic strain performs variously in different places and in different time, it is even popular within the immuned chickens. The test is to separate viruses from some pathological materials in the ill chickens, using continuous passage of chick embryo and animal regression experiment. We found out that dead embryos shrinked, the veins shrinked too, with its dropping off,what's more, we found the obvious incrassation of chorioallantoic membrane, living chickens appears dwarfism until day 19 of embryo age. Animal regression experiment can duplicate the KIB.Through the prima facie, we separated the virus of KIB—GZ strain.Through the serological and RT-PCR identity, the result of the test showed:we could conform that the virus we separated was the IBV, GZ strain and BJ strain,LX4 strain all belonged to the KIB strain, but they belonged to the separate branches in ribonucleotide and amino acid phylogenic trees.Because of the frequent varies of IBV viruses, common serological Vaccines can't protect the various strains well, our test would do proper enlargement of culture to the strain separated. After blanching the observed allantoic fluid, we mixed it and fat phase in proper proportion to compound the vaccine, after which we would do field testing to test its immune potency, and compare it to the abroad vaccines. Our experiment showed:after immunity, GZ strain could produce antibody more early and stained longer than other vaccines, its immune potency was higher too, and its protective rate to eliminating toxic material chicken was 100 percents. Through autopsia in vivo tested chickens, we could found out the pathological changes of adrenal gland. After inoculating the blanching vaccine of GZ strain, the reversibility of adrenal gland is slighter than the pathological changes of 3 domestic vaccines, with the equivalent to the aboard vaccines, as a result, it belonged to the pathological changes of reversibility.The experimental shows that to control the local epidemic strain we should chose the vaccines strain with match for better.