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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 Ectoparasites of goat with special reference to mange mite(College of Veterinary Science, Assam Agricultural University, Khanapara Campus, 2022) Borah, Debjani; Neog, RanjeetA study was conducted in and around Guwahati for a period of one year from July 2021 to June 2022 to study the prevalence of different ectoparasites in goats. Different ectoparasites in goat found to be prevalent in this area were ticks (67.32 %), lice (43.02%), flea (68.44%) and mite (14.38%). Haemaphysalis bispinosa, H. hystricis, Rhipicephalus (Boophilus) microplus, Linognathus africanus, Damalinia (Bovicola) caprae, Ctenocephalides felis orientis, C. canis, C. felis felis and Sarcoptes scabiei var. caprae were the prevalent species of ectoparasites found throughout the year. In the present study Linognathus africanus and Damalinia (Bovicola) caprae were reported for the first time in goat in Assam. Seasonal prevalence of the ectoparasites was studied in different climatic conditions of Assam namely temperature, humidity and rainfall. Prevalence of tick was found to be highest in the pre-monsoon season (March, April and May). The highest prevalence of lice, flea and mite was observed in the winter season (December, January and February). A significantly higher prevalence of tick and flea was observed in female goats than the male ones whereas prevalence of lice and mite was not dependent on the gender of the goats examined. Prevalence of ticks and mite was significantly higher in goats aged more than 6 months. Significantly higher prevalence of flea was observed in the goats below 6 months of age. Prevalence of lice was independent of age. Doramectin (Advanto®) @1ml/50kg b.wt. showed better results in the treatment of goats naturally infested with Sarcoptes scabiei var. caprae in comparison to Ivermectin (Parid pour-on @1ml/10kg b.wt.) and Castor oil (an indigenous knowledge-based acaricide). The haemoglobin, PCV, TEC and lymphocyte levels in the treated goats were observed to have a highly significant increase (p<0.01) post-treatment (day 48). The TLC, neutrophil and eosinophil levels showed a highly significant decrease (p<0.01) and monocyte per cent were observed to have a significant decrease (p<0.05) after treatment (day 48) with the three acaricides. Oxidative stress parameters revealed that malondialdehyde (MDA) level was seen to be higher and the superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities were seen to be lower in goats infested with S. scabiei var. caprae mite in comparison to their normal range of healthy goats kept as control. This implies that the goats infested with S. scabiei var. caprae were in a state of oxidative stress prior to the treatment(s) and with the progress of the treatment(s), the goats showed a significant decrease in MDA level and increase in SOD and GPx activities indicating a reduction of oxidative stress in the treated goats due to the treatment(s).ThesisItem Open Access Tick and tick-borne parasitic diseases of dog prevalent in and around Guwahati, Assam(College of Veterinary Science, Assam Agricultural University, Khanapara Campus, 2022) Devi, Pallavi; Islam, SaidulThe study was conducted to record the prevalence of ticks on dog and haemoparasites borne by them. Molecular identification and characterization of the prevalent tick species was also done in order to know their taxonomic status and evolutionary relationship. The study was conducted from March, 2021 to February, 2022. 1440 dogs were examined for the presence of ticks on their body. Out of 1440 dogs, 986 (68.47%) were found to be infested with ticks. 504 (35.00%) ticks were identified as Rhipicephalus sanguineus, 260 (18.06%) were identified as Haemaphysalis bispinosa and 222 (15.42%) were found to be mixed infestation. The highest prevalence of R. sanguineus ticks during August (61%) and the lowest during February and December (25%). Highest prevalence of H. bispinosa was recorded during August (26.67%) and the lowest during February and January (10.00%). Mixed infestation was highest during August (35.0%) and lowest during December (5.0%). The month-wise prevalence was found to be non-significant by statistical analysis (P value: 0.964948). The highest prevalence of ticks was recorded during the monsoon (95.42%) followed by the post-monsoon and the lowest during winter (37.5%). Statistically season has no significant influence on the prevalence of ticks on dogs (P value: 0.6541). The highest percentage of dogs infested with Rhipicephalus and Hemaphysalis tick at the age of 2-3 years (53.49%) and 6 month to 1 year (18.24%) respectively and lowest in 9-10 years (0%). The prevalence of ticks was significantly influenced by the age of dogs (P: 2.28695E-08). Labrador breed of dogs (98.23%) were found to be most infested by ticks followed by Local/mongrel (91.30%) and the least in St. Bernard (7.14%). The breeds of dog were found to be significantly influence the prevalence of ticks (P: 2.1666E-17). The female dogs showed higher prevalence of ticks (52.54%) than their male counterparts (47.46%). The most preferred site of attachment of the ticks on the dog‟s body was ears (28.39%) followed by head (18.56%) and paws/toes (17.64%). Morphological study of both the prevalent tick species were done and characteristic diagnostic features were figured out with photograph. Molecular identification and characterization of prevalent tick species were done by amplification of the 16S rRNA gene by PCR. Phylogenetic analyses by neighbor joining method were performed and the pair wise distance of 16S rRNA were done with MEGA X software. The pair wise distance study revealed that the R. sanguineus strain As/AAU/RS-01 was found to be 100% identical to the isolates of tropical lineages and is 6.4-7.5% divergent with the isolates of temperate lineages. H. bispinosa strain AS/AAU/HB-01 formed the clade with other isolates of H. bispinosa. The closely related isolates of AS/AAU/HB-01 were observed to be Chipahikhola isolate, Itanagar isolate and Arunachal pradesh isolates. The pair wise distance of AS/AAU/HB-01 showed divergence of 0-3.6% with other isolates of H. bispinosa and with other species of Haemaphysalis was between 9.3-14%. 4119 numbers of Giemsa‟s stained thin blood smears were examined under the light microscope for presence of tick-borne hemoparasites. The prevalent of five tick borne haemoparasites in dogs were recorded were Babesia gibsoni (10.34%), Babesia canis (0.92%), Hepatozoon canis (0.39%), Anaplasma (Ehrlichia) platys (0.12%) and Ehrlichia canis (0.22%). Out of 526 positive blood samples, 100 randomly selected positive samples were confirmed with PCR by amplification of 18S rRNA gene for (B. gibsoni, B. canis, H.canis) and 16S rRNA gene for (A. platys and E. canis) and found that PCR shows more sensitivity than light microscopy. Overall prevalence of tick borne haemoparasites, irrespective of season, breed, age and sex is recorded to be highest in the month of July (16.92%) followed by September (16.19%) and lowest in the month of February (4.18%).The highest prevalence of Babesia gibsoni was noticed in Labrador breed (12.93%) followed by local/mongrel dogs (11.53%) while Babesia canis was mostly encountered in Lhasa apso dogs (2.63%) followed by Boxer breed (2.38%) of dogs. Similarly, Pomeranian breed was found to be mostly infected by Hepatozoon canis (1.96%) followed by Doberman (1.55%) dogs. On the other hand, the rickettsial organism Anaplasma platys affect mostly Shitzu (3.85%) dogs followed by Dalmatian breed of dog (2.56%) and Ehrlichia canis was found to affect mostly Lhasa apso (2.63%) followed by Boxer dogs (2.38%). It has been noticed that out of all 18 breeds of dog in the present study, Labrador breed of dog is found to infect most by different haemoparasites followed by local/ mongrel dogs. Female dogs were recorded to be more affected than the male dogs. Statistical analysis revealed that sex of dog has significant influence on the prevalence of tick-borne hemoparasites (P: 0.040134). The highest prevalence of hemoparasites was seen in 1-2 years of age (17.70%) followed by <1 year (16.32%) and 2-3 years (14.88%) of age. The lowest prevalence was observed in 11-12 years of age (2.86%) and mixed infection of Babesia canis and Babesia gibsoni is found to be highest of all other combination of infection.ThesisItem Open Access Efficacy of selected herbal preparations against gastrointestinal nematodes with special reference to haemonchus contortus in goats(College of Veterinary Science, Assam Agricultural University, Khanapara Campus, 2022) Deka, Neelakshi; Phukan, Sulekha ChoudhuryThe present study was carried out to ascertain the prevalence of gastro-intestinal nematode parasites of goats in and around the undivided Kamrup district of Assam and to estimate the anthelminthic efficacy of the three selected indigenous herbal plants viz., Butea frondosa (Polakh), Carica papaya (Omita) and Corchorus fascicularis (Morapat) by in-vitro and in-vivo evaluation in goats naturally infected with gastro-intestinal nematodes. The study was conducted for a period of one-year w.e.f. October 2020 to September 2021 in Kamrup Rural and Metro districts of Assam. A total of 576 faecal samples were collected for the study. Faecal examination by Flotation Technique and Modified McMaster Method was carried out and overall prevalence of gastro-intestinal nematodes was recorded to be 63.89 %. Month-wise prevalence of gastro-intestinal nematode was also recorded where July month recorded the highest prevalence of 91.84 percent and February recorded the lowest prevalence of 31.81 percent. Monsoon season recorded the highest prevalence of 84.28 percent and winter season recorded the lowest prevalence of 35.06 percent. Among the three breeds of goat examined during the present study, Assam Hill goats recorded highest prevalence of 69.80 percent. The 6 months to 1 year age-group animals showed highest prevalence of 76.42 percent and female animals (doe) recorded the highest prevalence of 76.34 percent. The positive faecal samples were put in faecal culture for development of nematode larvae which revealed Haemonchus sp., Trichostrongylus sp., Oesophagostomum sp. and Strongyloides sp. larva in the study area. Polymerase chain reaction (PCR) was employed for molecular identification of Haemonchus contortus which showed a distinct band at 265 bp. Three types of leaf extract viz., ethanolic, hydroethanolic and aqueous extracts of each of three plants were prepared. The percent yield of ethanolic extract of B. frondosa, C. papaya and C. fascicularis was found to be 11.02, 7.81 and 13.72 % (w/w) respectively. For hydroethanolic extract the percent yield was found to be 12.81, 15.19 and 19.60 % (w/w) respectively and the percent yield of aqueous extract was found to be 16.02, 35.28 and 32.87 % (w/w) respectively. Phytochemical analysis of ethanolic, hydroethanolic and aqueous extract of leaves of B. frondosa, C. papaya and C. fascicularis revealed the presence of flavonoids, glycosides and triterpenes. Acute toxicity studies with ethanolic, hydroethanolic and aqueous extracts of the leaves of B. frondosa, C. papaya and C. fascicularis did not show any behavioural change or gross abnormality within 48 hours @ 2000 mg/kg body weight in mice. The extracts were considered to be safe up to a maximum dose of 2000 mg/kg. Three different concentrations viz., 50, 100 and 200 mg/ml was used for all the nine leaf extracts prepared from the three plants. Among the three plants studied in in-vitro trial, B. frondosa was observed as the best plant having in-vitro anthelminthic efficacy. Based on the findings of the in-vitro studies, the hydroethanolic extract of B. frondosa was selected to undergo in-vivo evaluation in goats naturally infected with Haemonchus sp., Trichostrongylus sp., Oesophagostomum sp. and Strongyloides sp. using two doses, 250 and 500 mg/kg body weight. At 250 mg/kg body weight, the percent efficacy was 80.18 % and 72.79 % on Day 7 and 14 respectively, and at 500 mg/kg body weight the percent efficacy was 69.46 % and 73.12 % on Day 7 and 14 post-treatment respectively. The pulverized leaves of B. frondosa was also incorporated in urea-molasses-block (MUMB, Herbal Anthelminthic) and fed to goats naturally infected with Haemonchus sp., Trichostrongylus sp., Oesophagostomum sp. and Strongyloides sp. The anthelminthic efficacy upon feeding of medicated urea molasses block (MUMB, Herbal Anthelminthic) incorporated with B. frondosa was found to have 88.16 % and ii 86.34 % efficacy on Day 7 and 14 post-treatment respectively. Ivermectin was used as the standard anthelminthic drug which gave 96.90 % and 93.79 % efficacy on Day 7 and 14 post-treatment respectively. Haemato-biochemical studies of treated goats under the in-vivo trial showed significant improvement in haemoglobin, packed cell volume, total erythrocyte count and total leukocyte count in groups fed with hydroethanolic extract of leaves of B. frondosa and MUMB (incorporated with B. frondosa) from Day 0 pre-treatment to Day 28 post-treatment. Total protein and albumin concentration improved significantly in groups treated with hydroethanolic extract of B. frondosa. Aspartate transaminase and alanine transaminase was found to improve significantly in groups treated with hydroethanolic extract of leaves of B. frondosa and MUMB (incorporated with B. frondosa) from Day 0 pre-treatment to Day 28 post-treatment. B. frondosa leaf extract and MUMB was found to possess significant in-vitro and in-vivo anthelminthic activity and improved the haemato-biochemical parameters substantially during the present study. This indicates that B. frondosa has the potential to be used as herbal anthelminthic. MUMB with herbal incorporation can be recommended to be used for the control of gastro-intestinal nematodosis in goats. This indicates that the extract of leaves of B. frondosa is a potent and effective herbal anthelminthic. Incorporation of the herbal leaves as powder form in medicated urea molasses block (MUMB, Herbal Anthelminthic) can be used for the control of gastro-intestinal nematodes in goats. The conventional use of synthetic anthelminthics has led to the development of anthelminthic resistance in goat farms not only in Assam but also India and the world as a whole. Therefore, newer anthelminthics need to be developed to overcome the problem of anthelminthic resistance and control of gastro-intestinal nematode parasites of goat.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.
