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Anand Agricultural University, Anand

Anand Agricultural University (AAU) was established in 2004 at Anand with the support of the Government of Gujarat, Act No.(Guj 5 of 2004) dated April 29, 2004. Caved out of the erstwhile Gujarat Agricultural University (GAU), the dream institution of Sardar Vallabhbhai Patel and Dr. K. M. Munshi, the AAU was set up to provide support to the farming community in three facets namely education, research and extension activities in Agriculture, Horticulture Engineering, product Processing and Home Science. At present there seven Colleges, seventeen Research Centers and six Extension Education Institute working in nine districts of Gujarat namely Ahmedabad, Anand, Dahod, Kheda, Panchmahal, Vadodara, Mahisagar, Botad and Chhotaudepur AAU's activities have expanded to span newer commodity sectors such as soil health card, bio-diesel, medicinal plants apart from the mandatory ones like rice, maize, tobacco, vegetable crops, fruit crops, forage crops, animal breeding, nutrition and dairy products etc. the core of AAU's operating philosophy however, continues to create the partnership between the rural people and committed academic as the basic for sustainable rural development. In pursuing its various programmes AAU's overall mission is to promote sustainable growth and economic independence in rural society. AAU aims to do this through education, research and extension education. Thus, AAU works towards the empowerment of the farmers.

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2000 - 200912010 - 20121
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Subject: Veterinary Microbiology × Thesis Type: M.V.Sc ×
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    ThesisItemOpen Access
    PATHOLOGICAL, IMMUNOSUPPRESSIVE AND VIRUS DETECTION STUDIES ON INFECTIOUS BURSAL DISEASE IN EXPERIMENTALLY INFECTED LAYER CHICKEN
    (AAU, Anand, 2000) KANANI, A. N.; JHALA, M. K.
    Infectious bursal disease (IBD) is a wide spread, contagious, acute or more commonly a subclinical viral disease of young chicken characterized by severe morbidity and mortality. The virus causes lymphocytolysis in the lymphoid organs particularly the Bursa of Fabricius (BF) resulting in immunosupression, vaccine failure and surfacing of latent/subclinical/concurrent infections. The pathologenicity, immunosuppressive effect, antigen detection and electrophoretic studies on Infectious bursal disease virus (IBDV) were carried out in experimentally infected layer chickens. The bursal samples were collected from the dead or ailing birds showing specific lesions of EBD when brought for post mortem examinations at the Dept. of Veterinary Pathology with a history of high mortality and were tested for the presence of viral antigen using agar gel diffusion test (AGDT). The experimental infection was induced in three and four weeks-old chicks by intra occulonasal route of inoculation using ten per cent bursal suspension. The birds of both the groups were vaccinated using LaSota strain of NewCastle Disease (ND) vaccine at seven and twenty nine days of age. Bursae were collected at two, four, six, eight, fifteen, twenty two, twenty nine and thirty six days post-infection (PI) for antigen detection, histopathological and electrophoretic studies. Sera were collected at the same intervals for monitoring ND virus haemaggutination inhibition (HI) antibody response to study immunosuppressive effect of BBD on ND vaccinations. Following the experimental infection, birds of both the age groups showed clinical symptoms of dullness, depression, ruffled feathers, whitish diarrhoea, prostration, huddling to corner and reluctance to move. Number of birds showing severe clinical signs were higher in four weeks age group than that in three weeks of age. Two and 11 per cent mortality were found in the groups infected at three and four weeks of age respectively. The remaining birds apparently recovered clinically within a period of six days PI and appeared normal till the end of observation period. In the birds infected at three weeks of age, grossly bursa was found to be enlarged and oedematous with yellowish gelatinous transudate covering on its serosal surface at 48 hrs PI Pin-point haemorrhages were also seen on bursal mucosa. Bursa started regressing in size to appear atrophied after seven days PI which and did not return to normal upto 36 days PI. Haemorrhages on thigh and breast muscle were also observed at 48 hrs PI. Spleen, thymus and kidney showed enlargement at 96 hrs PI. Similarly, birds infected at four weeks of age showed enlarged and oedematous bursa with extensive haemorrhages throughout the entire bursa in most of the birds at 48 hrs PI Bursa started showing progressive atrophy from seven days PI and did not return to normal upto 36 days PI. Marked haemorrhages in thigh and breast muscles were also observed. Lesions in other organs were similar to that observed in three weeks old birds but were of more severe nature., Histopathological lesions of BF in birds infected at three weeks of age showed mild depletion of lymphocytes, vascular congestion and inter-follicular connective tissue proliferation at 48 hrs PI. Marked depletion of lymphocytes, presence of necrotic foci and inter-follicular heterophilic infiltration were noticed on fifth day PI. On seventh day PI, the bursal follicle showed cystic degenerative changes with hyperplasia and hypertrophy of corticomeduUary epithelium. From ninth-day PI onward, BF showed severe depletion of lymphocytes, formation of cystic spaces and extensive interstitial fibroplasia. There was marked reduction in size of the bursal follicles. The group of birds infected at four weeks of age showed similar lesions to those observed in the group infected at three weeks of age but severity of lesions was more pronounced. Bursal lesions were characterized by marked depletion of lymphocytes in bursal follicles, cystic degeneration of follicles and moderate to severe infiltration of heterophils and mononuclear cells in the inter-follicular space at 48 hrs PI. On fifth day PI, necrosis was evident in the bursal follicle. On seventh day PI and onwards cystic hyperplasia and hypertrophy of follicles were noticed giving adenomatoid appearance. There was marked reduction in size of the follicles from seventh day onwards till the end of experiment upto 36th day PI. For studying immunosuppressive effect of EBDV, sera collected at regular interval after the experimental infection were tested for presence of NDV antibody using HI test. Geometric mean titre (GMT) of the NDV antitodies in the infected birds were found significantly lower than that of the control birds in both the experimental groups, Boostering effect of ND vaccination done at 29 days of age was found lower in the infected birds than the controls. Age susceptibility for in munosuppression was not found among these two experimental groups. AGDT was used to detect IBDV antigen in the bursae collected at regular intervals PI by the field virus. IBDV antigen was detected upto sixth day PI in both the experimental groups. Thereafter, the antigen could not be detected in any of the two groups till the end of experimental period. For electrophoretic study, IBDV RNA was extracted from live Gumboro vaccine (Georgia strain) and AGDT positive bursal samples. RNA of IBDV was extracted after serial treatment of proteinase K digestion, phenol-chloroform extraction and ethanol precipitation and then electrophorsed in 0.8 per cent agarose gel. Two bands of ds RNA from the vaccine virus but not in the bursal samples were resolved when stained with ethidium bromide and visualized under UV transilluminator.
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    ThesisItemOpen Access