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ThesisItem Open Access Isolation, characterization and morpho-biometric evaluation of pre-pubertal porcine spermatogonial stem cells in different culture media(College of Veterinary Science, Assam Agricultural University, Khanapara Campus, 2022-03) Lalmasawma, Timothy; Das, ArpanaTestes samples were collected from 7-15 days old pre-pubertal male crossbred piglets (Local × Hampshire) for isolation, enrichment and in vitro culture of porcine spermatogonial stem cells (SSCs). Isolation of spermatogonial stem cells like cells was performed by double enzymatic digestion using four enzymes viz., collagenase, DNase I, hyaluronidase type II and trypsin-EDTA. Isolated cells were further enriched by differential plating and percoll density gradient centrifugation method. Enriched cells were cultured on Sertoli cell feeder layer in three different culture media. All the three media consisted of same concentration of DMEM, NEEA, L-glutamine, FBS, EGF and FGF, however in addition to these, LIF was added to media I, GDNF was added to media II and both LIF and GDNF were added to media III. Characterization of SSCs was done by alkaline phosphatase and immunoflourescence staining. Expression of SSC specific pluripotent marker genes by putative SSCs was also studied by RT-PCR study. Porcine SSCs were observed as dome shaped round or oval bodies on 5th -6th day of culture in all the three media. Clustering of cell was observed from 4th -5th day of culture and single, paired or multiple colonies were observed from 8-10th day of culture. The SSCs colonies appeared as mulberry, grape or rosette shaped with irregular distinct boundary from feeder layer on 15th - 19th day of culture in all the three media. However, the shape of the SSCs was found to be distorted with increase in the days of culture. The morphology of the SSC colonies was maintained best up to 30th day of culture in media III. The SSC colony number was recorded as 82.14 ± 2.91, 60.07 ± 2. 78 and 48.43 ± 1.96 on 5th, 15th and 30th day of culture respectively in media I. The corresponding numbers were 91.71 ± 2.62, 67.00 ± 2.05 and 57.29 ± 2.17 in media II and 105.93 ± 2.82, 80.21 ± 2.45 and 62.50 ± 2.09 in media III respectively. The SSC colony diameter was found to be 64.26 ± 0.85, 125.30 ± 1.88 and 123.01 ± 5.49μm on 5th, 15th and 30th day of culture respectively in media I. The corresponding values were 69.67 ± 1.12, 139.58 ± 3.93 and 142.08 ± 5.72μm in media II and 76.49 ± 1.61, 152.55 ± 4.07 and 172. 08 ± 4.96μm in media III respectively. The day of culture and culture media had significant effect (P≥0.01) on SSC colony number and significantly higher number of SSC colony was observed on day 5 and lower was on day 30 of culture in all the three media. The SSC colony number was significantly higher in media III containing both GDNF and LIF. The diameter of SSC colony differed significantly (P≥0.05) due to day of culture and culture media. The interaction between day of culture and culture media was also significant (P≥0.01). The colony diameter recorded on day 30 of culture was significantly higher, whereas lower number was recorded on day 5 of culture in all the culture media. Diameter of SSC colony obtained in media III was found to significantly higher and the lower diameter was obtained in media I on all the day of culture. It was observed that the SSC colony number decreased and colony diameter increased with the day of culture from day 5th to 30th day of culture in all the media.The putative SSCs in all the three media showed positive result for alkaline phosphatase and immunofluorescence staining. The putative SSCs in all the three media were also found to express SSC specific pluripotent marker genes viz., OCT4, SOX2, NANOG and maximum expression was observed in media III, however, no expression was recorded for c-KIT and PPARγ which were known to be the markers for differentiated SSCs. BAX4, an apoptopic marker gene was also expressed by putative SSCs in all the three media. Based on the findings of the present study, it may be concluded that a pure population of porcine spermatogonial stem cells (SSCs) could be obtained and successfully maintained in vitro up to 30th day of culture. Media III containing DMEM, FBS, NEAA, L-glutamin, FGF, EGF, LIF and GDNF was found to be the best for in vitro culture of porcine SSCs.ThesisItem Open Access Effect of feeding protected proteins on milk yield and nutrient utilization in crossbred cows(College of Veterinary Science, Assam Agricultural University, Khanapara Campus, 2022-09) Haloi, Sikhamoni; Bhuyan, RobinAn experiment was conducted to assess the effect of feeding protected proteins on milk yield, milk quality, nutrient utilization and cost of production in crossbred cows. Eighteen lactating crossbred cows of almost similar milk yield and parity were randomly divided into three groups of six animals each. Randomized block design (RBD) technique was followed for the study. Experimental cows were allotted to three dietary treatments (T0, T1 and T2). T0 was considered as control group and T1 and T2 as treatment groups. Feeding of roughage and concentrate mixture having soybean meal (untreated) was offered in T0 group; while concentrate mixture with heat treated and formaldehyde treated soybean meal was offered to T1 and T2 group, respectively. The feeding trial was conducted for a period of 120 days followed by digestibility trial of 5 days. The average dry matter (DM) intake (kg/Day) was 10.98±0.04, 11.05±0.05 and 11.02±0.05 for T0, T1 and T2 groups, respectively and did not differ significantly among groups. The DM intake (kg) per 100 kg body weight was 3.34 ±0.07, 3.40 ±0.07 and 3.35 ±0.05 for T0, T1 and T2 group, respectively. The DM intakes (g) per kg W0.75 body size was 141.92 ± 2.21, 144.44 ± 2.22 and 142.32 ± 1.31 for the corresponding groups. The DM intake per 100 kg body weight and per kg W0.75 body size did not differ significantly among groups. The percent digestibility of DM, CP were significantly higher in T1 and T2 group over T0 group, however digestibility of EE, CF, NFE, NDF and ADF did not differ significantly among groups . The average daily milk yield (kg/Day) was 7.70 ± 0.98, 9.01 ± 0.14 and 8.93 ± 0.14 for the T0, T1 and T2 group, respectively which was significantly higher (P<0.01) in T1 and T2 group compared to T0 group. The average FCM yield (kg/Day) was 8.12 ± 0.16, 9.42 ± 0.17 and 9.30 ± 0.18 in T0, T1 and T2 respectively which was significantly higher (P<0.01) in T1 and T2 group in comparison to T0 group. The milk parameters like fat, protein, lactose, total solid, solid not fat did not differ significantly among groups. The total serum protein (g/dl), albumin (g/dl) and albumin globulin ratio was significantly higher (P<0.01) in T1 and T2 group compare to T0 group. The creatinine (mg/dl) and globulin (g/dl) concentration of blood were significantly lower in (P<0.01) in T1 and T2 group compared to T0 group. The gamma glutamyl transferase (U/L) concentration of blood was comparable among the groups. Rumen degradable protein (RDP) percentages were 26.47 ± 0.02, 22.52 ± 0.01 and 22.53 ± 0.02 for untreated, heat treated and formaldehyde treated soybean meal, respectively. Undegradable dietary protein (UDP) percentages were 18.55± 0.01, 22.51 ± 0.01 and 22.52 ±0.01 for the corresponding feeds. RDP percentages were lower in (P<0.01) in heat treated and formaldehyde treated soybean meal than untreated soybean meal whereas UDP percentages were significantly higher (P<0.01) in heat treated and formaldehyde treated soybean meal compared to untreated soybean meal. The feed cost per kg of milk was lower in T1 and T2 groups (Rs.28.77 and Rs.29.60) compared to T0 (Rs.32.83) group. It was observed that feeding of heat treated soybean meal (T1) and formaldehyde treated soybean meal (T2) showed better results in terms of milk yield, FCM yield and digestibility of nutrients like dry matter and crude protein over untreated soybean meal (T0). Hence, it can be concluded that treatment of soybean meal has a significant effect on milk yield due to enhancement of nutrient bioavailability caused by lowering of rumen degradable protein (RDP). Comparing the heat treatment and formaldehyde treatment of soybean meal, heat treatment could be recommended from practical and economic point of view as there is no risk of chemicals.ThesisItem Open Access Effect of selenium and zinc-oxide nanoparticles on cryopreserved semen quality and fertility of Assam hill goat(College of Veterinary Science, Assam Agricultural University, Khanapara Campus, 2022) Abedin, Sayed Nabil; Baruah, AnubhaNanoparticles (NPs), due to their smaller size and unique surface properties can be incorporated into a variety of reproductive biology procedures. The present investigation was carried out from September, 2021 to July, 2022 on four (4) Assam Hill Goat bucks (10 ejaculates per buck) to investigate the effect of supplementing zinc oxide (ZnO) and selenium (Se) NPs in TRIS extender on seminal attributes, lipid peroxidation (LPO) profile, antioxidant enzyme activities viz., superoxide dismutase (SOD), catalase (CAT) and Glutathione-S-transferase (GST), relative heat shock protein (HSP) mRNA levels and fertility of cryopreserved Assam Hill Goat semen. The size morphology and zeta potential values of ZnO and Se NPs were evaluated. Qualified semen samples were divided into five (5) aliquots and then diluted in TRIS extender containing ZnO and Se NP supplementation at different concentrations (T0: control; T1: 0.1mg/mL ZnO NPs; T2: 0.5 mg/mL ZnO NPs; T3: 0.5 μg/mL Se NPs and T4: 1 μg/mL Se NPs). Diluted semen was packed in 0.25 mL straws and then stored in liquid nitrogen. After thawing, post-thaw attributes viz., motility, viability, morphology, plasma membrane integrity (PMI), DNA integrity and mitochondrial membrane potential (MMP) were evaluated. The different treatment groups were also checked for potential NP internalization under transmission electron microscope (TEM). Lastly, straws from the best among the ZnO and Se NP treatments were used for artificial insemination (AI) in does (n=35) synchronized by Ovsynch protocol. Results showed that ZnO and Se NPs were poly-crystalline in nature with particle size below 100 nanometers. The evaluated post-thaw sperm in vitro attributes were significantly (p<0.05) higher in groups containing ZnO and Se NPs supplementation in comparison to control group. Overall, ZnO NPs @ 0.1 mg/mL (T1) had significantly (p<0.05) higher post-thaw sperm in vitro attributes in comparison to Se NPs @ 1 μg/mL. ZnO and Se NP supplementation also significantly (p<0.01) lowered cryocapacitated (B and AR pattern) spermatozoa in comparison to control. The antioxidant enzyme activities (SOD, CAT and GST) were significantly (p<0.001) higher in T1 in comparison to T0. The LPO was significantly (p<0.001) lowered in T1, T2, T3 and T4 in comparison to T0. The leakages of functional enzymes viz., aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) were significantly (p<0.001) lower in T1 in comparison to other groups. Post-thaw sperm motility and MMP had a highly significant(r=0.580, p<0.05) association in T1. SOD (r=0.445) and CAT (r=0.949) had a highly significant (p<0.05) correlation with sperm motility in T1. No internalization of ZnO and Se NPs were observed under TEM. HSP70 and HSP90 mRNA levels were significantly (p<0.001) higher in T1 in comparison to other groups. HSP70 and HSP90 expression levels had a significant (p<0.05) positive correlation with motility in group T1. No significant (p>0.05) differences in pregnancy rates following AI were recorded among the different treatment groups in comparison to control. In conclusion, extender supplemented with 0.1 mg/mL ZnO NPs improved post-thaw semen quality of cryopreserved Assam Hill goat spermatozoa consequently by lowering lipid peroxidation and increasing expression of cryostress associated heat shock genes.ThesisItem Open Access Development of a chitosan based packaging film incorporated with zinc oxide nanoparticles and green tea extract : its effect on shelf life of meat and meat product (chicken)(College of Veterinary Science, Assam Agricultural University, Khanapara Campus, 2022-09) Upadhyay, Santosh; Nath, RitaThe present work was aimed at developing an active biopolymeric packaging film based on chitosan with antioxidant and antimicrobial activity and to assess its effect on shelf life of meat and meat product. Zinc oxide nanoparticle (ZnO NP) at a concentration of 2%w/w of chitosan and green tea extract (GTE) at 0.2% w/w of chitosan film was used after determining the antimicrobial activity of ZnO nanoparticles using agar well diffusion assay and antioxidant activity of GTE using DPPH inhibition assay. Four different combinations of films were prepared- F1 (Chitosan alone), F2 (Chitosan+ZnONPs), F3 (Chitosan+GTE) and F4 (Chitosan+ZnONPs+GTE) and compared with commonly used LDPE (control) packaging film for their physicochemical, mechanical, antioxidant and antimicrobial activities. The SEM of the films at resolution of 5000x revealed uniformity of the film in all four different types of combinations confirming the proper dissolution of the added zinc oxide nanoparticles and green tea extract in the film. All the four combinations of films were transparent and of desired thickness. The films F2 and F4 were found to have tensile strength but low elongation at break % as compared to LDPE. The films F2 and F4 showed potent antimicrobial property as compared to other films while F3 and F4 showed potent antioxidant activity. The film F4 possesses both strong antioxidant and antimicrobial activity with good tensile strength and was found to be the best among all the four film combinations. The developed films were then used for wrapping of fresh meat and meat loaf (chicken) and to assess their effect on shelf life at both ambient and refrigeration temperature. Samples without film were used as negative control. The fresh meat wrapped with F4 could maintaining the quality attributes in terms of physicochemical properties like TBARS, pH, colour and microbiological qualities like standard plate count and coliform count below the threshold level up to 12 hours at ambient temperature and up to 9 days of storage at refrigeration temperature. The meat loaf wrapped with F4 could be kept up to 15 hours of storage at ambient temperature and up to 15 days of storage at refrigeration temperature maintaining the quality attributes in terms of pH, TBARS, SPC, colour and textural properties. Sensory panel evaluation also suggested that the meat loaf wrapped with F4 remained acceptable up to 15 days at refrigeration temperature with good sensory scores. A significant difference (p<.01) in crude protein and ether extract contents were observed in the fresh meat and meat loaf without film and those wrapped with F1, F2 and F3. However, minimum decline was observed in samples wrapped with F4. Migration studies on zinc oxide nanoparticles revealed no significant migration of zinc oxide nanoparticles from the film to the food matrix.ThesisItem Unknown Interaction studies of microbial enzymes and phytochemicals of Bael (Aegle marmelos) in flavour enhancement cow's milk ghee(College of Veterinary Science, Assam Agricultural University, Khanapara Campus, 2022) Saikia, Rashmi Rekha; Borpuzari, TrishnaA study was conducted to develop flavour and colour enhanced cow’s milk ghee using starter cultures as a source of microbial enzymes and phytochemicals of bael (Aegle marmelos) fruit pulp extract. The experiment was conducted in the laboratories of the Department of Livestock Products Technology, the All India Coordinated Research Project on Post-Harvest Engineering and Technology, the Department of Livestock Production and Management, the Department of Veterinary Biochemistry, College of Veterinary Science, Assam Agricultural University, Khanapara, Guwahati–781 022; and the Central Analytical Instrumentation Facility, Guwahati Biotech Park Incubation Centre of the Indian Institute of Technology, Amingaon, Kamrup, Guwahati-781 031 during the period from August 2020 to April 2022. Lactococcus lactis ssp. lactis var. diacetylactis and yoghurt cultures of Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus were used @ 3% (v/v) in the study. Bael pulp extract was added @ 1% (v/v) to the treatment groups. Cow’s milk ghee was prepared by the heat clarification method. The flavour and colour qualities, FFA contents, antioxidant compounds, sensory attributes, proximate composition and shelf-life of the cow’s milk ghee thus prepared were studied. The ghee was stored at ambient temperature to study the shelf-life. A total of 34 flavour compounds were detected in the samples of the treatment groups as well as the reference sample by GC-MS studies. Identical numbers of FFA were also detected in the ghee samples. The flavour of the ghee was attributed by the FFA along with the other flavouring compounds like the alcohol, hydrocarbons, ketones, terpenoids, organic acids and 9 other compounds identified in the ghee samples. Ascorbic acid, thymol, phytol and β-sitosterol were the four antioxidant compounds detected by GC-MS. The maximum radical scavenging activity (60.160±0.541%) was observed in the sample of T4. Bael pulp extract added ghee samples had higher DPPH inhibition activity as compared to the other groups and the reference sample. Colour component b* was found in higher values in bael pulp extract added ghee samples. Highly significant positive correlation was found between the sensory evaluation scores for colour and the colorimetric assessment of the colour components (b* value). Higher panel ratings for flavour and colour of the samples of T4 group indicated that bael pulp extract indeed had a positive effect on the flavour and the colour characteristics of cow’s milk ghee. The moisture and ash contents of the ghee were highly significantly influenced by the starter cultures and addition of bael pulp extract while only significant difference could be found in their protein content. Shelf-life study was done based on the FFA and peroxide values. Correlation studies revealed a highly significant difference between FFA and PV while a negative correlation existed between the FFA x antioxidant activity and PV. A gradual increase in FFA and PV along with the increase during the storage period was found in all the treatment groups. Even after 6mon of storage, FFA and PV were found to be much lower than those recommended by the FSSAI (2016). From the study it was found that the starter culture Lc. lactis ssp. lactis biovar diacetylactis used in the study in combination with the bael pulp extract produced cow’s milk ghee with improved flavour and colour attributes and had an extended shelf-life at room temperature.ThesisItem Unknown Effects of housing management on dairy cow productivity(College of Veterinary Science, Assam Agricultural University, Khanapara Campus, 2022) Deka, Raj Jyoti; Baruah, Dilip KumarThe experiment was carried out from January to December, 2021 on different types of housing systems adopted for dairy farming viz. i) Institutional Housing (IH) adopted at institutional level following all the scientific approaches at Instructional Livestock Farm (Cattle) under the Department of Livestock Production and Management, College of Veterinary Science, Assam Agricultural University, Khanapara, Guwahati-22 and ii) Traditional Housing (TH) adopted by progressive dairy farmers of Amerigog area in Kamrup (M) District of Assam. The experiment was carried out with a total of 36 (Thirty Six) lactating dairy animals (crossbred cows) keeping 18 numbers of animals each under IH (Institutional Housing) and TH (Traditional Housing) management systems. Furthermore, each group was sub-divided into three groups viz. T0, T1 and T2 with 6 (Six) animals in each treatment group. The 6 (Six) animals per group was selected on the basis of apparently similar in parity, physiological status and preceding lactation yield. Two different treatments were applied in two different IH and TH management system with one group as control in each housing management system i.e. IH and TH. The T0 was considered as the control without treatment and was managed under existing (regular) management system. The T1 was supplemented with dry yeast powder (Saccharomyces cerevisiae) with the recommended dose @3.0 gm per cow as probiotics over regular management system and the T2 was supplemented with dry yeast powder (Saccharomyces cerevisiae) with the recommended dose @3.0 gm per cow as probiotics over regular management system and modification of the micro climate for more air circulation by fixing dairy fan (side fan). The highest maximum temperature (33.83±0.28 0C) was recorded in the month of August and the lowest minimum temperature (12.66±0.37 0C) was recorded in the month of January during the year in both G1 & G2. The mean monthly lowest outdoor temperature (O Temp.) was recorded as 18.10 ± 0.22 0C and 18.16±0.22 0C in the morning and 22.06±0.38 0C and 22.14±0.38 0C in the afternoon during the month of January in G1 and G2 respectively. The highest outdoor temperatures were 31.17±0.43 0C and 31.28±0.43 0C in the morning and 32.38±0.62 0C and 32.33±0.59 0C in the afternoon during the month of September in the G1 and G2 respectively. The mean monthly highest wind speed (Km/hr.) were 3.07±0.62 both in G1 and G2 in the month of April and 2.58±0.68 and 2.47±0.69 in G1 and G2 in the month of March in morning and afternoon respectively. The lowest mean wind speed (Km/hr.) were 0.21±0.21 both in G1 and G2 in the month of February and 0.13±0.09 and 0.17±0.07 in G1 and G2 in morning and afternoon respectively. The lowest mean monthly wet bulb temperatures (WB Temp.) in the morning were 15.17±0.21 and 15.23±0.23 0C in the month of January both in G1 and G2 respectively. However highest mean monthly morning WB Temp. were recorded as 26.89±0.16 0C in the month of August in G1 and 26.75±0.23 0C in the month of September in G2. The mean relative humidity (RH) in percentage were 87.26±1.00 as highest in the month of January and 69.63±1.78 as lowest in the month of April in G1 and 88.90±0.93 as highest in the month of January and 63.27±0.82 as lowest in the month of November in the morning in G2. The analysis of variance (ANOVA) revealed that there is highly significant (P<0.01) difference in DB Temp., RH and THI among the two different housing management viz. institutional housing (G1) and traditional housing (G2). Whereas, there were no significant differences in O Temp., WB Temp. and WS among G1 and G2. But there were highly significant (P<0.01) differences between the months in O Temp., WB Temp., WS, DB Temp., RH and THI. The overall mean body surface temperature (ST) comprising of all the four seasons were 36.44±0.06 & 36.44±0.06 0C in T0, 36.41± 0.10 & 36.41± 0.10 0C in T1 and 36.32±0.08 & 36.32±0.08 0C in T2 in the morning and afternoon respectively in G1. The overall mean rectal temperature (RT) comprising of all the four seasons were 38.18±0.14 & 38.18±0.14 0C in T0, 37.96± 0.27 & 37.96± 0.27 0C in T1 and 37.72±0.18 & 37.72±0.18 0C in T2 in the morning and afternoon respectively in G1. Whereas, the ST were recorded as 38.29±0.13 & 38.51±0.10 in T0, 38.09±0.21 & 38.32±0.15 in T1 and 37.85±0.23 & 37.94±0.24 in T2 in the morning and afternoon respectively in the G2. The overall mean respiration rate (RR) comprising of all the four seasons were 23.97±0.26 & 23.97±0.2614 0C in T0, 23.80± 0.21 & 23.80± 0.21 0C in T1 and 23.64±0.15 & 23.64±0.15 0C in T2 in the morning and afternoon respectively in G1. Whereas the RR were recorded as 25.13±0.34 & 25.67±0.61 in T0, 24.52±0.30 & 24.65±0.34 in T1 and 23.99±0.18 & 24.20±0.20 in T2 in the morning and afternoon respectively in the G2. The overall mean pulse rate (PR) comprising of all the four seasons were 57.42±0.22 & 57.42±0.22 0C in T0, 57.08± 0.21 & 57.08± 0.21 0C in T1 and 56.97±0.13 & 56.97±0.13 0C in T2 in the morning and afternoon respectively in G1. Whereas the PR were recorded as 57.99±0.24 & 58.16±0.25 in T0, 57.64±0.24 & 57.85±0.31 in T1 and 57.39±0.22 & 57.64±0.21 in T2 in the morning and afternoon respectively in te G2. The analysis of variance (ANOVA) revealed that there are significant differences (P<0.01) between the G1 and G2 in respect of surface temperature, rectal temperature, respiration rate and pulse rate. There were non-significant differences (P>0.05) between morning and afternoon in respect of ST, RT, RR and PR. However, there were highly significant differences (P<0.01) were recorded between the seasons in respect to ST, RT, RR and PR. Highest ST were observed in S1 (36.57±0.04 0C) followed by S3, S2 and S1. The total leukocyte count (TLC) were recorded in percentage (%) as 22.57±1.67, 18.30±1.51 and 15.75±1.38, 15.13±0.87, 13.55±1.40 and 12.79±0.89, 23.66±0.96, 21.46±0.94 and 15.44±1.42, 24.02±1.42, 25.76±3.10 and 17.47±0.80 in treatment groups T0, T1 and T2 and during the seasons viz. S1, S2, S3 and S4 respectively in institutional housing (IH). Whereas, the TLC were 19.73±3.19, 19.35±3.12 and 18.36; 18.14±3.11, 15.00±1.68 and 13.93±2.87; 21.61±3.53, 18.36±2,29 and 20.08±2.00; 24.81±3.44, 20.13±2.52 and 19.90±1.29 in treatment groups T0, T1 and T2 and during the seasons viz. S1, S2, S3 and S4 respectively in traditional housing (TH). The analysis of variance revealed that there are non-significant differences in TLC and DLC irrespective of housing management i.e. IH and TH. However, highly significant differences (P<0.01) were observed in TLC, neutrophil count, lymphocyte count and monocyte count among the seasons irrespective of IH and TH. But no significant differences were recorded among the treatment group. The overall mean RBC in percentage in T0, T1 and T2 were 5.51±0.38, 6.06±0.36 and 5.94±0.43 in IH and 5.06±0.26, 4.89±0.27 and 4.98±0.29 in TH. The overall mean PCV in percentage in T0, T1 and T2 were 24.72±1.39, 26.63±1.41 and 27.16±1.45 in IH and 24.85±1.65, 24.49±1.53 and 24.50±1.56 in TH. The overall mean Hb in percentage in T0, T1 and T2 were 9.55±0.36, 10.19±0.42 and 10.23±0.42 in IH and 9.98±0.57, 9.57±0.44 and 9.71±0.39 in TH. The analysis of variance (ANOVA) revealed that there are significant differences (P<0.01) between IH and TH in regards to RBC and PCV, whereas no significant difference was observed between IH and TH in terms of Hb content of blood. But, highly significant (P<0.01) differences were observed between the seasons in RBC, PCV as well as Hb concentration. Moreover, non significant differences were also observed among the treatment groups in terms of RBC, PCV and Hb content of blood. The overall mean cortisol level (nmol/L) in T0, T1 and T2 were 34.60±5.73, 28.56±6.58 and 21.11±3.32 in IH and 31.74±4.28, 27.60±6.12 and 21.90±2.67 in TH. The overall mean T3 level (nmol/L) in T0, T1 and T2 were 1.51±0.07, 1.41±0.07 and 1.29±0.05 in IH and 1.49±0.11, 1.43±0.09 and 1.29±0.05 in TH. The overall mean T4 level (nmol/L) in T0, T1 and T2 were 42.69±7.92, 37.20±7.57 and 34.88±6.99 in IH and 45.48±7.26, 38.77±6.94 and 34.47±5.79 in TH. The analysis of variance revealed that there were non-significant (P>0.05) between the IH (G1) and TH (G2) in terms of the hormonal parameters viz. Cortisol, T3 and T4. But highly significant (P<0.01) differences have been observed among the seasons in terms of Cortisol and T4. The level of T3 is not significant (P>0.05) between interaction of the seasons. Moreover, highly significant (P<0.01) levels of Cortisol and T3 were recorded among the treatment groups viz. T0, T1 and T2, where, T4 level was significant (P<0.05) among the treatment groups. The mean daily milk yield (Lt.) were recorded as 6.66± 0.97, 6.61± 0.77 and 8.84± 1.13 in IH (G1) and 8.99± 1.08, 9.08± 1.00 and 9.98± 0.66 in TH (G2) in the treatment groups viz. T1, T2, T3 respectively. The analysis of variance indicated that there were highly significant (P<0.01) differences in average daily milk yield between G1 (IH) and G2 (TH), where, average daily milk yield highest (9.35±0.29) in G2 (TH). Highly significant differences (P<0.01) were also observed among the treatment group viz. T0, T1 and T2. Highest (9.40±0.36) mean daily milk was observed in T2. The mean daily milk per month were also highly significant (P<0.01). The mean fat percentage (%) in the collected milk samples were recorded as 4.62±0.15, 4.92±0.03 and 5.02±0.07 in IH and 4.58±0.14, 4.96±0.06 and 5.11±0.12 in TH in the treatment groups viz. T0, T1 and T2 respectively. The mean solids not fat (SNF) percentage (%) were recorded as 8.73±0.03, 8.80±0.04 and 8.81±0.03 in IH and 8.77±0.03, 8.83±0.03 and 8.84±0.02 in TH in the treatment groups i.e. T0, T1 and T2 respectively. The mean total solids (TS) percentage (%) were recorded as 13.34±0.19, 13.49±0.17 and 13.46±0.18 in IH and 13.32±0.20, 13.53±0.17 and 13.48±0.18 in TH in the treatment groups i.e. T0, T1 and T2 respectively. The mean protein percentage (%) in the collected milk samples were recorded as 3.44±0.02, 3.48±0.02 and 3.69±0.16 in IH and 3.47±0.02, 3.50±0.01 and 3.75±0.18 in TH in the treatment groups viz. T0, T1 and T2 respectively. The mean lactose percentage (%) in the collected milk samples were recorded as 4.45±0.01, 4.44±0.00 and 4.45±0.02 in IH and 4.46±0.02, 4.45±0.01 and 4.49±0.03 in TH in the treatment groups viz. T0, T1 and T2 respectively. The mean ash percentage (%) in the collected milk samples were recorded as 0.78±0.00, 0.79±0.00 and 0.79±0.00 in IH and 0.78±0.00, 0.79±0.00 and 0.79±0.00 in TH in the treatment groups viz. T0, T1 and T2 respectively. The mean laying and standing time (hrs.) were 16.78± 0.10 and 3.24± 0.09, 16.91± 0.09 and 3.09± 0.09 and 17.19± 0.08 and 2.81± 0.08 in T0, T1 and T2 respectively in IH during the S1; 16.70± 0.12 and 3.33± 0.10, 16.83± 0.09 and 3.17± 0.09 and 17.12± 0.09 and 3.02± 0.15 in T0, T1 and T2 respectively in IH during the S2; 15.95± 0.23 and 4.05± 0.23, 16.05± 0.18 and 3.95± 0.18 and 16.71± 0.14 and 3.42± 0.25 in T0, T1 and T2 respectively in IH during the S3 and 16.13± 0.18 and 4.37± 0.49, 16.20± 0.19 and 3.80± 0.19 and 16.63± 0.17 and 3.37± 0.17 in T0, T1 and T2 respectively in IH during the S4. Furthermore, the mean laying and standing time (hrs.) in TH were 16.82± 0.11and 3.17± 0.07, 17.00± 0.12 and 3.00± 0.12 and 17.28± 0.11 and 2.72± 0.11 in T0, T1 and T2 respectively during the S1; 16.64± 0.13 and 3.39± 0.11, 16.67± 0.16 and 3.33± 0.16 and 17.04± 0.10 and 3.09± 0.14 in T0, T1 and T2 respectively during the S2; 16.05±0.22 and 3.95±0.22, 16.05±0.18 and 3.95±0.18 and 16.73±0.14 and 3.41± 0.25 in T0, T1 and T2 respectively during the S3 and 16.24± 0.13 and 3.76± 0.13, 16.26± 0.15 and 3.74± 0.15 and 16.70± 0.13 and 3.44± 0.23 in T0, T1 and T2 respectively during the S4. The mean Barn Used Pattern (BUP) in terms of Cow Comfort Index (CCI) and Stall Standing Index (SSI) have been recorded as 81.95 & 18.74 and 82.19 & 17.84 in T0; 82.49 & 17.51 and 82.48 & 17.53 in T1 and 84.56 & 15.78 and 84.69 & 15.83 in T2 in two different housing system i.e. IH (G1) and TH (G2) respectively. The analysis of variance revealed that there were no significant (P>0.05) differences in the barn used pattern of cows between the housing system, seasons and treatment groups viz. T0, T1 and T2. But there were highly significant differences (P<0.01) in CCI and SSI (laying and standing position).ThesisItem Unknown Epidemiology of rabies in Assam(College of Veterinary Science, Assam Agricultural University, Khanapara Campus, 2022-09) Boro, Prasanta Kumar; Dutta, Jyoti BIn an epidemiological study on rabies in 11 districts in Assam, 65 post-mortem brain samples belonging to nine species were collected by foramen magnum approach from clinically suspected domestic and wild animals and tested at the WOAH Reference Laboratory for Rabies, Hebbal, Bengaluru – 560 024, Karnataka. Simultaneously, a questionnaire survey on the community was undertaken to evaluate the epidemiological determinants on rabies transmission. Forty two (64.61 %) samples tested positive by LFA and DFA. Of the nine species, five species i.e. cattle 27 (41.53%), dog 9 (13.85%), goat 4 (6.15%), pig 1(1.53%) and pony 1(1.53%) were confirmed for rabies. Aggression in 41 (97.62%) cases was the most common signs exhibited by the affected animals before death with only one positive case (2.38%) showing paralytic signs. There was no dog bite history in 33 (78.57%) cases while 9 (21.43%) cases had. Most of the livestock were free ranging and grazed nearby protected areas where presences of wild carnivores were evident. Seasonal distribution revealed similar numbers of cases (45.24%) during rainy and flood season (July-September) and post-harvesting (December-February) winter season. Gender-wise, 20 (47.62%) positive cases of cattle and goats were either pregnant or recently calved. Prevalence of rabies was found to be highest (64.29%) in the animals more than 3 years of age, followed by the animals between 1 to 3 years (23.81%) and below one year of age (11.90%). In rural areas distribution of rabies was highest (52.31%), semi-urban (9.32%) and urban (3.08%). Distribution maps of rabies in different parts of Assam were generated based on the GPS locations of the positive cases and heat map revealed a high risk zone in the Golaghat district. The areas adjoining the tea gardens had higher rabies cases (23, 54.76%). The questionnaire survey revealed a very low level of community awareness regarding rabies and its transmission. Lack of proper information from the field staff, immediate collection of samples from field and transportation of samples to the laboratory maintaining cold chain were the major constraints found during the study.ThesisItem Unknown Detection and deactivation of antimicrobial residues in pork(College of Veterinary Science, Assam Agricultural University, Khanapara Campus, 2022-09) Debbarma, Param; Laskar, S KThe present study aims to detect antimicrobial residues in collected pork samples, isolation and in-vitro study of the resistance pattern of meat-borne pathogens (Escherichia coli, Salmonella spp. and Staphylococcus aureus) against 12 commonly used antimicrobials in pig husbandry and effect of different cooking methods (viz, boiling, roasting and microwaving) on deactivation/inactivation of antimicrobial residues. The preliminary screening of 261 pork samples by microbial inhibition assay using endospores of Bacillus subtilis MTCC 441 as test organism revealed that none of the samples were positive for antimicrobial residues except 3 (three) which were doubtful to have traces of antimicrobial residues. A total of 80 pork samples were further screened by Ultra-Fast Liquid Chromatography system (Model: Shimadzu Prominence LC-20AD, Detector-SPD-20AUV/ Vis; C18 Column: BDS Premium, 250 mm x 4.6 mm, 5 m) to detect OTC, TTC, CIP and GEN residues. OTC and CIP residues were detected in 2.5% and 1.25% of the samples, while none of the samples detected TTC and GEN residues. The overall recovery rate of Escherichia coli, Salmonella spp. and Staphylococcus aureus from the pork samples were 28.75%, 9.09% and 31.25%, respectively. All the isolates showed variable ranges of resistance against the tested antimicrobials. Highest resistance was recorded against ampicillin (75-100%), followed by trimethoprim (37.5-100%), cefepime (25-75%), nalidixic acid (12.5-62.5%), sulfafurazole (0-37.5%), ciprofloxacin (0-37.5%), chloramphenicol (0-37.5%), ceftriaxone (0-25%) and amoxiclav (0-12.5%). All the isolates however, recorded 100% sensitivity against amikacin, gentamicin and tetracycline. The effect of cooking viz. boiling, roasting and microwaving revealed significant reduction (p˂0.001) in the residual concentration of antimicrobials (OTC, TTC, CIP and GEN). Cooking by microwaving recorded highest reduction (44.48-91.06%) followed by roasting (32.11-85.92%) and boiling (22.02-73.33%). Thus, cooking temperature and time can have a significant effect on the losses of antimicrobial residues and provides an additional safety margin to the consumers.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.