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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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ThesisItem Open Access Epidemiology and molecular identification of trematode parasites of duck with special reference to echinostome(College of Veterinary Science, Assam Agricultural University, Khanapara Campus, 2022-03) Borah, Nanswita; Phukan, Sulekha ChoudhuryA survey was conducted in five different districts of Assam for a period of one year from September‟ 2020 to August‟2021 to investigate on the epidemiology and molecular identification of trematode parasites of duck along with the pathological changes caused by the latter and furthermore, identification of the snail harboring the echinostome cercariae and molecular identification of echinostome cercariae. Out of 1411 fresh faecal samples examined, 411 samples were found positive for helminths with 29.13 per cent prevalence. Infectivity percentage was highest in Kamrup (rural) district and lowest in Udalguri district. Trematodes evinced highest prevalence of 18.00 per cent followed by nematodes with prevalence of 17.51 per cent and finally cestodes with lowest prevalence of 2.62 per cent. Study revealed eggs of Notocotylus sp., Prosthogonimus sp., Echinostoma sp., segments of cestodes, larvae of Strongyloides avium, porrocaecum sp., Tetrameres sp., Heterakis sp. in faecal samples of infected ducks. 303 faecal samples were positive for single infection with prevalence of 21.47 per cent and 108 samples were positive for mixed infection with prevalence of 7.65 per cent. The seasonal prevalence of trematodes on faecal examination of ducks from different districts of Assam depicted highest in monsoon with 28.93 per cent and lowest in winter with 7.82 per cent. The prevalence of trematodes on faecal examination of duck raised under free-range was higher (19.91%) than semi-intensive system of rearing (16.10%). Out of 2786 ducks examined on post-mortem, 2092 ducks were found positive for helminths with 75.09 per cent prevalence. Infectivity percentage was highest in Kamrup (rural) district and lowest in Udalguri district, respectively. Cestodes showed overall highest prevalence of 50.90 per cent followed by trematodes with prevalence of 44.29 per cent and finally nematodes with lowest prevalence of 17.26 per cent. 1146 ducks with an overall prevalence of 41.13 per cent were positive for single infection and 946 ducks with prevalence of 33.96 per cent for mixed infection. On the basis of morphological studies, 9 different species of trematodes, 7 different species of cestodes and 4 different species of nematodes were identified and recorded. Trematodes were identified as Echinostoma revolutum (7.11%), Echinostoma paraulum (18.23%), Echinostoma friedi (0.29%), Hypoderaeum conoideum (18.52%), Psilochasmus oxyurus (0.04%), Tracheophilus cymbius (0.04%), Prosthogonimus ovatus (0.04%), Notocotylus attenuates (0.04%). Cestodes were identified as Hymenolepis collaris (14.28%), Hymenolepis lanceolata (11.59%), Fimbriaria fasciolaris (7.93%), Raillietina tetragona (4.74%), Raillietina echinobothridia (5.03%), Raillietina cesticillus (3.30%), and Amoebotaenia cuneata (4.02%). Nematodes were identified as Porrocaecum sp. (0.68%), Heterakis gallinarum (5.53%), Heterakis dispar (4.02%), and Tetrameres sp (7.04%). Notocotylus attenuates and Amoebotaenia cuneata was first time reported from Assam in duck. The prevalence of trematodes on post-mortem examination of ducks on the basis of sex depicted higher prevalence in females (46.00%) than males (42.62%). The prevalence of trematodes in post-mortem examination of ducks on the basis of age showed higher in adults (48.93%) than young ducks (38.95%). The prevalence of trematodes on post-mortem examination of ducks on the basis of breed showed highest in Pati ducks (49.24%), followed by Khaki Campbell ducks (45.76%), Chara-chambelli ducks (42.14%) and lowest in White pekin ducks (39.16%). Seasonal prevalence of trematodes on post-mortem examination of ducks depicted highest in monsoon with 49.62 per cent and lowest in winter with 38.25 per cent. Prevalence of trematodes on ii post-mortem examination of ducks on the basis of rearing duck showed higher in free-range (47.44%) than semi-intensive system of rearing (40.91%). For molecular identification of trematodes namely, Echinostoma revolutum, Echinostoma paraulum, Hypoderaeum conoideum and Echinostoma friedi (morpholocigally identified) were subjected to PCR (COX -1 gene of Echinostoma revolutum, Echinostoma paraulum, Hypoderaeum conoideum and ITS2 gene of Echinostoma friedi). The trematode, Echinostoma revolutum collected from different districts on the basis of COX-1 sequence identity showed 97.80-99.63% identity with Echinostoma revolutum, Echinostoma paraulum collected from different districts on the basis of COX-1 sequence identity showed 99.07-99.54% identity with Echinostoma robustum, Hypoderaeum conoideum collected from different districts on the basis of COX-1 sequence identity showed 99.08%-99.74% identity with Hypoderaeum conoideum. Echinostoma friedi on the basis of ITS2 sequence identity from Kamrup (rural) and Kamrup metropolitan districts showed 100% identity with Echinostoma friedi. DNA extracted from adult trematode parasites yielded positive results for COX-I genes of E. revolutum, E. paraulum and Hypoderaeum conoideum by PCR analysis, yielded the amplicons size of 818 bp, 216 bp, and 765 bp, respectively and 1000bp for E. friedi for ITS2 gene. On post-mortem examination, intestine of ducks infected with the species under the genus Echinostoma and Hypoderaeum showed slight gross lesions except catarrhal enteritis and congestion in the mucosal surface, mainly in the jejunum, ileum and caecum. Psilochasmus oxyurus showed catarrhal enteritis and congestion in the mucosal surface of the small intestine. Trachea infected with Tracheophilus cymbius exhibited bloody mucosal exudates in the site of attachment. No observable gross pathological lesions could be seen in oviduct and caecum affected with Prosthogonimus ovatus and Notocotylus attenuates, respectively. This may be due to low level of infection encountered in the present investigation. Microscopic changes associated with the species under the genus Echinostoma, Hypoderaeum, and Psilochasmus showed marked thickening with infiltration of inflammatory cells including lymphocytes, eosinophil, plasma cells and macrophages in the intestine. Some of the villi were degenerated and necrosed. Desquamated epithelial lining of intestinal villi were found to be deposited in the lumen of the intestine. Haemorrhagic patches could be seen in the tip of some villi. Hypertrophy of goblet cells was seen in the villi. The glandular epithelium showed vasculation and distortion which have further undergone necrosis. Most of the lymphoid follicles in ileum were found to be enlarged and degeneration of lymphoid cells was also observed. Muscle cells showed necrosis and hyalinization. Blood vessels showed congestion and dilation along with haemorrhages in subserosal layer of intestine. Histopathology, of trachea infected with Tracheophilus cymbius showed heavy infiltration of leucocytes in the mucosa and degeneration with necrosis in submucosal layer. Snail, Indoplanorbis exustus (0.55%) and Lymnaea luteola f. ovalis (0.37%) were recorded as the intermediate host of echinostome cercariae. No cercarial infection was recorded from Lymnaea acuminata f. rufescens, and Bellamya bengalensis f. typica. District-wise Monthly prevalence of echinostome cercaria in Indoplanorbis exustus depicted maximum shedding from the month of June to September from the different districts of Assam. District-wise Monthly prevalence of echinostome cercaria in iii Lymnaea luteola f. ovalis depicted maximum shedding from the month of June to October from the different districts of Assam. Morphological identified echinostome cercariae (4 representative samples) collected from different districts of Assam were subjected for molecular identification where ITS2 and COX -1 gene of the parasite was subjected to PCR. Cercariae of Hypoderaeum conoideum and Echinostoma revolutum (molecularly identified) are commonly prevalent in the snails of Assam.ThesisItem Open Access INVESTIGATION ON PARASITES OF DUCK IN UPPER ASSAM WITH SPECIAL REFERENCE TO HAEMOPROTOZOA(College of Veterinary Science, Assam Agricultural University, Khanapara, Guwahati-781022, 2017-07) Borah, Nanswita; Phukan, Sulekha ChoudhuryA survey was conducted in seven districts of upper Assam for a period of one year from June, 2016 to May, 2017 to study the prevalence of parasites of domestic ducks in upper Assam. Out of a total of 675 numbers of ducks examined, 467 ducks were found positive for different ectoparasites showing the overall prevalence of 69.19 per cent. Ducks from Gaurisagar of Sibsagar district had highest 92.86 per cent and Lahowal of Dibrugarh district had lowest 58.82 per cent prevalence for ectoparasites. Five different lice and two different types mites were recovered from different body parts of duck, of which infestation with Lipeurus caponis (13.33%) was highest followed by Menopon gallinae (12.74%), Menacanthus stramineus (10.67%), Columbicola columbae (8.44%), different feather mites viz. Dubininia melopsittaci, Megninia ginglymura and Bdellorhynchus sp. (5.19%), Goniodes sp. (3.70%) and larva of Trombiculid mite (0.89%), respectively. The three feather mites, larva of the Trombiculid mite and Columbicola columbae were first time reported from Assam in duck. Examination of 724 faecal samples collected from different localities of upper Assam revealed 333 samples to be positive for helminthes with overall prevalence of 45.99 per cent. Out of the positive samples, 314 samples were positive for single and 19 for mixed infection with incidence of 94.29 per cent and 5.71 per cent. Samples from Gaurisagar of Sibsagar district had highest 68.96 per cent of helminthic infection. Helminthic infections of ducks were not recorded from samples collected from Baghchung of Jorhat district and Joysagar of Sigsagar district. Faecal samples collected from ducks reared under free range system had highest prevalence of 57.84 per cent for helminthes followed by semi intensive system of rearing (35.34%) and no helminthic infections were recorded from faecal samples of ducks reared under intensive system. Season wise prevalence of helminths in ducks on the basis of faecal examination revealed highest during pre monsoon (73.56%) and lowest during winter (20.92%). Out of 724 faecal samples examined, 20 samples were positive for Coccidia (Isospora sp.) with the overall prevalence of 2.76 per cent. Post mortem examination of 774 carcasses of ducks from different localities of different districts in upper Assam revealed 518 carcasses to be positive for helminthic infections. The overall prevalence of helminthes was recorded as 66.93 per cent. 232 carcasses were found positive for cestodes (44.79%), 241 for trematodes (46.52%) and 45 for nematodes (8.69%). Carcasses from Demow of Sibsagar district had highest prevalence of 86.05 per cent and lowest from Kakopathar of Tinsukia district with 50.00 per cent prevalence for helminthes. Post mortem examination of ducks reared under free range system revealed highest 78.21 per cent for helminthes followed by semi intensive system of rearing (70.33%). Helminthic infection was not recorded from ducks reared under intensive system. Seasonal prevalence of helminthes on the basis of post mortem examination revealed highest during monsoon (72.28%) and lowest during winter season (51.43%). On the basis of morphological studies, 7 different species of cestodes and 1 larval stage of cestode, 8 different species of trematodes and 5 different species of nematodes were identified and recorded. Highest incidence of cestodes was recorded with Hymenolepis collaris (35.78%) followed by Hymenolepis carioca (35.34%), Fimbriaria fasciolaris (22.41%), Hymenolepis lanceolata (1.74%), Raillietina tetragona (1.29%), Raillietina echinobothridia (1.29%) and Raillietina cesticillus (1.29%) and lowest with plerocercoid (0.86%). Highest incidence of trematodes was recorded with Echinostoma revolutum (24.07%), Hypoderaeum sp. (18.67%), Psilorchis sp. (18.67%), Echinostoma paraulum (16.60%), Paryphostomum sp. (10.79%), Prosthogonimus sp. (8.30%), Tracheophilus cymbius (2.07%) and Psilochasmus sp. (0.83%). Highest incidence of nematodes was recorded with Tetrameres sp. (57.78%), Heterakis gallinarum (17.78%), Heterakis dispar (17.78%), Strongyloides avium (4.44%) and Porrocaecum sp. (2.22%). Hymenolepis carioca, Hymenolepis lanceolata, Raillietina tetragona, Hypoderaeum sp., Echinostoma paraulum, Prosthogonimus sp., Psilochasmus sp. and Heterakis dispar were first time reported from Assam in duck. Seasonal prevalence of helminthes according to breeds of duck revealed highest prevalence of helminthes in monsoon season (82.54%) and lowest in winter (26.67%) from Patihanh, highest in pre monsoon (85.26%) and lowest in monsoon (54.29%) from Khaki Campbell, highest in pre monsoon season (85.37%) and lowest in winter (56.52%) from Chara ducks and prevalence of helminthes in Muscovy ducks during monsoon season was 80 per cent. Overall prevalence of helminthes was recorded highest in adults (76.73%) and lowest in young ducks (54.41%). Seasonal prevalence of helminthes according to age of ducks revealed highest prevalence of helminthic infection during pre monsoon (67.83%) and lowest during winter season (34.88%) in youngs and highest prevalence during post monsoon season (85.29%) and lowest during winter season (61.29%) in adults. Overall prevalence was recorded highest in female (67.44%) and lowest in male (66.41%). Seasonal prevalence of helminthes according to sex revealed that males had highest helminthic infection during monsoon (80.41%) and lowest during winter season (43.14%). Similarly, females had highest during pre monsoon season (73.88%) and lowest during winter season (57.41%). Prevalence of haemoprotozoa in ducks revealed that, out of 300 thin blood smears prepared, only 4 showed the presence of Haemoproteus sp. infection in RBC. The overall prevalence of infection was 1.33 per cent. Haematological changes observed due to helminthes and haemoprotozoan parasites of duck revealed decrease in Haemoglobin (9.38±0.13), PCV (27.98±0.36) and TEC (1.69±0.08) with increase in TLC (43.18±1.76) in infected ducks. On post mortem examination, various pathological lesions were found associated with Hymenolepis sp. and Echinostoma sp. in intestines and Tetrameres sp. in proventricles of ducks. Intestines of duck showed catarrhal enteritis and congestion in the mucosal surface of the small intestine for Hymenolepis sp. and haemorrhages and catarrhal enteritis for Echinostoma sp. Microscopic examination revealed marked thickening of intestinal villi with infiltration of inflammatory cells. Some villi showed haemorrhagic patches, degeneration and necrosis. Desquamated epithelial lining of intestinal villi were found to be deposited in the lumen of the intestine. Cross section of Hymenolepid parasite was found attached to the superficial epithelium surrounded by infiltrating cells. Gross examination of infected proventiculus revealed small blackish elevated spots visible from the luminal surface. Microscopic examination revealed cut sections of female parasite inside the proventricular gland. Glandular epithelium surrounding the parasite exhibited pressure atrophy and the lumen of the gland was found dilated. Tunica muscularis around the glands was found thickened and inter glandular spaces was found enlarged and thickened with proliferation of fibrous connective tissue and was found infiltrated with monocytes and polymorphs. The genera Echinostoma sp. (Identified as Echinostoma revolutum on the basis of morphological characteristics) and Hypoderaeum sp. were identified as Echinostoma friedi and Hypoderaeum conoideum on the basis of ITS2 sequence identity. The present isolate of Echinostoma sp. showed 100 % identity with Echinostoma friedi the isolate of Hypoderaeum sp. showed 99% identity with Hypoderaeum conoideum The Molecular characterization of either Echinostoma friedi or Hypoderaeum conoideum could not be accomplished due to unavailability of more than one ITS2 sequence of these species in NCBI database. Probably it might be the first report of Echinostoma friedi in India. The ITS2 sequence based species identification of Psilorchis sp. could not be accomplished due to absence of Psilorchis ITS2 sequence in NCBI database. This might probably be the first report of ITS2 sequencing of Psilorchis sp. either in India and abroad.
