No abstract

No abstract

A total of 240 unvaccinated day-old broiler chicks, which had been found to be negative for antibodies against FAV-4, were divided into four groups of 60 chicks each. Group A was fed aflatoxin at 1 ppm from 7 days to 7 weeks of age. Group V was infected intra-abdominally at 14 days of age with 0.2 ml of FAV-4, having a titre of 10(5.5) TCID50 per 0.2 ml. The combined group AV was given the aflatoxin and infected with FAV-4. The fourth group C served as the control. More pronounced clinical signs, a higher mortality rate (56.7%), and reductions in body weight gain and in the organ to body weight ratios of the bursa and spleen were recorded in group AV. A significant (p < 0.01) reduction in the HI antibody titre following vaccination against Newcastle disease, and of skin thickness in the delayed hypersensitivity test following sensitization with DNCB, indicated an additive immunosuppressive effect from aflatoxin and FAV-4 on the humoral and cell-mediated immune responses in group AV compared to groups A and V. Microscopically, marked depletion and degeneration of lymphocytes in the thymus, bursa, spleen and caecal tonsils were observed in group AV up to 5 weeks PI.

Mycoplasma gallisepticum (MG) is one of the major respiratory tract pathogens affecting chickens. It causes Chronic Respiratory Disease (CRD) among chickens of various age groups. The present study describes the isolation, molecular detection and histopathological changes associated with CRD in chickens. A total of 790 samples viz., trachea, lungs and air sacs were collected from chickens showing the symptoms of CRD from different parts of Tamil Nadu state. All the samples were processed for isolation and molecular detection of MG. A total of 91 samples were found positive by isolation and 105 samples were found positive through MG specific PCR targeting 16S rRNA gene. The histopathological changes in tissue samples of trachea, sinuses, air sacs and lungs collected from naturally infected M. gallisepticum infection were suggestive of subacute to chronic nature of infection. Though isolation is considered to be a gold standard, still PCR is a rapid, sensitive and cheap method for early diagnosis of MG which can help poultry farmers to avoid severe economic loss.

An unknown disease outbreak was reported in four villages of Salem district viz., Aranganoor, Athigaripatty, Avadathur and Amanikondalanpatty in Tamil Nadu State and subsequent mortality among the Mecheri breed of sheep and Tellichery breed of goat was investigated. The clinical signs observed among the animals were high fever, anorexia, profuse diarrhoea with bilateral mucopurulent oculonasal discharge. Bran like necrotic ulcers in the mucosa of oral cavity, tongue, dental pad was seen on necropsy. Samples were collected for laboratory based diagnostic assay and the investigation using RT-PCR confirmed the etiology as PPR. The Nucleoprotein gene of the virus was sequenced and phylogeny of the N gene sequence showed that the virus belongs to lineage IV PPRV.