The situation of infection and circulation of wild Marek, serotype1 virus in chickens in Cho Gao district, Tien Giang province

Abstract

Investigation on the farming situation and infection of Marek virus was conducted at 180 chicken farms in 6 communes of Cho Gao district, Tien Giang province, from September 2017 to November 2018. There were 300 wing feather-follicle samples collected from 100 chicken farms without MD clinical manifestations for testing by PCR method at the Veterinary Hospital of Nong Lam University in Ho Chi Minh City. The investigated results showed that the rate of indigenous broiler chickens raising by industrial method accounted for 35%; commercial egg laying chickens accounted for 65%. For the farming scale: farming at small level accounted for 12.78%; medium level accounted for 80.56%; and large scale accounted for 6.66%. One hundred percentage of the chicken farms were vaccinated against MD for the chicks at 1 day of age. The number of farm having the chickens ever infected with MD to be 107/180 (59.44%). In general,
the farmers applied biosecurity measures at their farms, but not yet comprehensive. The tested result for the wing feather-follicle samples of 100 chicken farms without MD clinical manifestations showed that there
was the circulation of the field MDV1 strain. The positive vaccine MDV1 and field MDV1 strains was 100%. The positive rate for both vaccine and field MDV1 strains was 38%. The rate of farms having positive wing
feather-follicle samples only with wild type Marek serotype 1 virus was 0%