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Assam Agricultural University, Jorhat

Assam Agricultural University is the first institution of its kind in the whole of North-Eastern Region of India. The main goal of this institution is to produce globally competitive human resources in farm sectorand to carry out research in both conventional and frontier areas for production optimization as well as to disseminate the generated technologies as public good for benefitting the food growers/produces and traders involved in the sector while emphasizing on sustainability, equity and overall food security at household level. Genesis of AAU - The embryo of the agricultural research in the state of Assam was formed as early as 1897 with the establishment of the Upper Shillong Experimental Farm (now in Meghalaya) just after about a decade of creation of the agricultural department in 1882. However, the seeds of agricultural research in today’s Assam were sown in the dawn of the twentieth century with the establishment of two Rice Experimental Stations, one at Karimganj in Barak valley in 1913 and the other at Titabor in Brahmaputra valley in 1923. Subsequent to these research stations, a number of research stations were established to conduct research on important crops, more specifically, jute, pulses, oilseeds etc. The Assam Agricultural University was established on April 1, 1969 under The Assam Agricultural University Act, 1968’ with the mandate of imparting farm education, conduct research in agriculture and allied sciences and to effectively disseminate technologies so generated. Before establishment of the University, there were altogether 17 research schemes/projects in the state under the Department of Agriculture. By July 1973, all the research projects and 10 experimental farms were transferred by the Government of Assam to the AAU which already inherited the College of Agriculture and its farm at Barbheta, Jorhat and College of Veterinary Sciences at Khanapara, Guwahati. Subsequently, College of Community Science at Jorhat (1969), College of Fisheries at Raha (1988), Biswanath College of Agriculture at Biswanath Chariali (1988) and Lakhimpur College of Veterinary Science at Joyhing, North Lakhimpur (1988) were established. Presently, the University has three more colleges under its jurisdiction, viz., Sarat Chandra Singha College of Agriculture, Chapar, College of Horticulture, Nalbari & College of Sericulture, Titabar. Similarly, few more regional research stations at Shillongani, Diphu, Gossaigaon, Lakhimpur; and commodity research stations at Kahikuchi, Buralikson, Tinsukia, Kharua, Burnihat and Mandira were added to generate location and crop specific agricultural production packages.

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20161
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Subject: Veterinary Pathology × Author: Pathak, Nayanjyoti × End date: 2019 × Start date: 2016 × Type: Thesis × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    PREVALENCE, PATHOLOGY AND MOLECULAR DIAGNOSIS OF POX IN DOMESTIC BIRDS
    (AAU, 2016) Pathak, Nayanjyoti; Baruah, G.K.
    In the present investigation a total of 29 nos. of fowlpox (FP), 13 nos. of pigeonpox (PP) and three nos. of duckpox (DP) outbreaks were recorded, where highest morbidity and cause specific mortality in case of FP was recorded at 0-8 weeks (19.63 % & 23.60 %) followed by 9-20 weeks (5.57 % & 14.43 %) and above 20 weeks (1.39 % & 11.11 %), respectively. Likewise, in PP highest morbidity was recorded at above 20 weeks (35.08 %) followed by 9-20 weeks (30.68 %) and 0-8 weeks (11.11 %). Highest cause specific mortality was recorded at 9-20 weeks (37.03 %) followed by above 20 weeks (30.00 %) and no mortality was recorded at 0-8 weeks. In case of DP outbreaks, highest morbidity was recorded at 0-8 weeks (10.00 %) followed by above 20 weeks (6.66 %), where no mortality was recorded among the ducks. During sero-surveillance study of FP, 27.88 % positive cases were detected by AGID, whereas 77.88 % positive cases were detected by ELISA. Similarly in case of pigeonpox and duckpox 26.82 % and 26.41 % positive cases were detected by ELISA, respectively but no positive cases were detected by AGID. Gross lesions during external examination revealed erosions, crusts and several small, multifocal to coalescing wart-like nodules on various parts of the affected fowls and pigeons, whereas in case of ducks lesions were mostly confined to bill and eye regions. During post-mortem examination of dead birds no any remarkable gross lesions were seen in various visceral organs where in few birds showed fibronecrotic lesions on mucous membrane of the oral cavity and upper respiratory tract. Microscopic lesions revealed varying degrees of hyperplasia and ballooning degeneration of the epithelial cells of the epidermis where most of the cells contained large eosinophilic intracytoplasmic inclusion bodies. During ultrastructural study, intracytoplasmic inclusion bodies were seen in the skin epithelium, which consist of numerous, dumbbell-shaped bodies typical of pox virions. During molecular diagnosis, out of 29 FP, nine PP and three DP suspected samples 86.20 %, 77.77 % and 100 %, respectively were found positive by polymerase chain reaction. Inoculation of fowlpox virus (FPV) in embryonated chicken eggs and inoculation of duckpox virus (DPV) in embryonated duck eggs for isolation showed positive results during the first passage itself , where as pigeonpox and duckpox viruses in embryonated chicken eggs required 2-3 initial passages to get the positive results. Out of the various field isolates, 10 nos. of FPV and six nos. of pigeonpox virus (PPV) were adapted on chorioallantoic membrane (CAM) of developing embryonated chicken eggs, whereas the virus isolated from ducks (n=3) were adapted on CAM of embryonated duck eggs. All total eight nos. of APV isolates were molecular biologically characterized. On phylogenetic analysis it was observed that all the isolates of APV of the present study were clustered along with other APVs corresponding to their species reported from different parts of the world. However, one isolate from duck was clustered along with the isolates of FP, which indicates natural adaptation of FPV in ducks. From the experimental study it was observed that all the chicks inoculated with FPV developed characteristic pox lesions (pustules) within 7-9 days post infection. Similarly, when pigeons were inoculated with PPV then all the pigeons developed pox lesions within 5-9 days. Again in case of ducklings all the ducklings inoculated with DPV developed pox lesions (nodular lesion) within 5-6 days. For comparative study when FPV, PPV and DPV were inoculated into heterologous hosts no lesions were developed. In seroconversion study of experimental birds by ELISA, all the infected birds (chicks, pigeons and ducklings) inoculated with species specific avipox virus showed presence of antibody. Antibody was also detected in 40 % pigeons and 60 % ducklings inoculated with FPV, 60 % chicks inoculated with PPV and 40 % chicks inoculated with DPV. The scab samples of experimentally infected chicks, pigeons and ducklings showed positive results by PCR but the biopsy samples collected from the inoculated site of the heterologous hosts showed negative results by PCR. Haematological studies in case of avipox infected fowl, pigeon and ducks from both field and experiment cases revealed low levels of haemoglobin, total erythrocyte count and total leucocyte count. In differential leucocyte count, lymphocyte and monocyte percentages were increased, whereas heterophil percentage was decreased in pox infected birds. From the experimental study it could be concluded that though the FPV, PPV and DPV field isolates of this study were host specific but if several passage done on heterologous host then it may adapt the virus and produce characteristic lesions in it. Further study will require to confirm host specificity of APVs.