Abstract:
Day-old chickens were inoctaated with 3000PFU of a bivalent Marek's disease vaccine(SB-1+HVT) and then challenged with virulent MDBJ-1 at 18 days of age.Three chickens were killed at regular intervals and were exa-mined for macroscopical or microscopical lesions of MD,Up till day 98, mild proliferation of reticulocytes or lymphocytes in the visceral tissues and the external nerves eras still seen.The bivalent vaccine was compared with HVT or SB-1 vaccines under the same conditions,The experimental res-ults showed that the occurrence, extent and degree of macroscopical Icsion and microscopical lymphocytes proliferation in various organs of the chickens immunized with the bivalent vaccine were less than those in the other challenged groups.Usually，the bivalent vaccine only caused mild mieroscopical lesions which were for a long time nontumorous.
Key words:
Marek's disease,
Bivalent vaccrne
Chen Peihong, Zhou Jiao, Jiang Guohua, Xu Weimin. A Study on the Pathological Changes of Chickens Immunized with rival ent Marek' s Disease Vacc ine[J]. ACTA AGRICULTURAE BOREALI-SINICA, 1990, 5(1): 111-116. doi: 10.3321/j.issn:1000-7091.1990.01.021.