Loading...
Kerala Veterinary and Animal Sciences University, Wayanad
Browse
30 results
Search Results
ThesisItem Open Access CHARACTERISATION OF AMITRAZ RESISTANCE IN RHIPICEPHALUS SANGUINEUS(COLLEGE OF VETERINARY AND ANIMALS SCIENCES MANNUTHY, THRISSUR , KERALA VETERINARY AND ANIMAL SCIENCES UNIVERSITY, 2023-01-25) SHAIK NIKHAT REENA; Dr. Bindu LakshmananRhipicephalus sanguineus, a three-host tick distributed across the world is an obligate ectoparasite with its primary host as dogs vectoring various pathogenic agents causing canine disease conditions such as babesiosis, ehrlichiosis and Q-fever. Use of chemical acaricides ubiquitously for the control of ticks had led to development of acaricide resistance against most of these chemicals. Early diagnosis of acaricidal resistance is necessary to avoid widespread dispersal of resistance and the awareness of mechanisms imparting resistance can help in devising resistance diagnosis tools such as molecular markers. The present study was conducted to assess the development of resistance to amitraz in brown dog ticks. Dog ticks were collected from naturally infested dogs, and the engorged female R. sanguineus s. l. were reared in laboratory conditions for egg laying and larval hatching. Adult immersion tests were performed to evaluate the effects of amitraz on mortality, reproductive index and percentage inhibition of oviposition. Non-linear regression analysis on mortality of ticks and log amitraz concentrations were done to calculate the LC50 of each isolate, that were utilized to calculate the resistance factors used to determine the resistance levels. The AIT results showed that resistance to amitraz at resistance levels II, III, IV is prevalent in different regions of Thrissur. And the negative slopes of reproductive index on log amitraz concentrations indicated that amitraz has a negative effect on egg laying. Larval packet test (LPT) was done and discriminating dose (DD) was arrived. The LPT-DD with only a single concentration of amitraz at 1200 ppm (DD), were performed to determine the survivability percentage of larvae exposed to amitraz. Resistance status was ascribed based on the percentage survivability of exposed larvae. The LPT-DD revealed that 48.57 per cent of field isolates were resistant of which 72.22 per cent were highly resistant with up to 90 per cent survival rate at the DD. Larvae from six of the resistant tick isolates were utilised to perform full-dose response bioassays (modified LPT) for each isolate revealing that the LC50 of each resistant tick isolate was very much higher than the field recommended dose of amitraz (250 ppm). Two levels of resistance level II and III were detected in four and two isolates, respectively. Molecular characterisation of resistance was done by PCR-RFLP, amplifying the exon 3 region of octopamine receptor gene of R. sanguineus s. l. followed by restriction digestion with the RE Tth111I to detect the mutation at position C75T. The results revealed that 97.5 per cent of larvae were homozygous susceptible (CC), while heterozygous susceptible (CT) genotypes were detected in 2.5 per cent larvae at position C75T. However, both susceptible and resistant populations were detected by bioassays in these isolates. The homozygous resistant genotype (TT) was not observed. Nucleotide sequence analysis was performed to identify mutations. Novel non-synonymous substitutions at positions T131C, A157G and G208A were observed in resistant tick isolates, which needs further studies to associate it with amitraz resistance.ThesisItem Open Access GENETIC ANALYSIS OF HOST RESISTANCE TO GASTRO INTESTINAL NEMATODE INFECTION AMONG NATIVE GOAT BREEDS OF KERALA(COLLEGE OF VETERINARY AND ANIMALS SCIENCES MANNUTHY, THRISSUR , KERALA VETERINARY AND ANIMAL SCIENCES UNIVERSITY, 2023-03-23) NIKHILA MOHANRESHMI RAVEENDRAN; Dr. K. SyamalaPresent study aimed at analysing the breed variation in host resistance and resilience towards natural gastro-intestinal nematode infection (GIN) and the association of two putative SNPs conferring host resistance in ATP2A3 and SERPING 1 genes was conducted among native goat breeds viz., Attappady Black (n= 51) and Malabari (n= 58) goats of Kerala. The host resistance and resilience were measured using faecal egg count (FEC) and volume of packed red cells (VPRC), respectively. The incidence (per cent) of strongylosis in goats ranged from 87.85 to 100 during the study period of June/ 2021 to October/2021. Larval culture revealed Haemonchus contortus as the most predominant strongyle species. Majority of goats (66.0031 per cent) were very heavily infected with FEC>1500. The correlation among FEC and VPRC was negative (r= -0.409) and highly significant (p<0.01). The genotyping of ATP2A3_680_A>C SNP by polymerase chain reaction– restriction fragment length polymorphism (PCR- RFLP) assay revealed that all the sampled animals were monomorphic for AA genotype. Bi- directional PCR allele specific amplification (Bi-PASA) assay showed the occurrence of all the three genotypes at SERPING1_312_C>T SNP locus. The influence of breed was highly significant (p<0.01) on FEC. The Malabari goats had significantly (p<0.01) lower FEC compared to that of Attappady Black goats. The effects of breed and genotypes of SERPING1_312_C>T SNP on VPRC were statistically significant (p≤0.01). The results indicated that Malabari goats were more resistant towards natural GIN compared to Attappady Black goats under semi-intensive system of rearing.ThesisItem Open Access MOLECULAR CONFIRMATION OF TRANSOVARIAL TRANSMISSION OF PATHOGENS THROUGH TICKS INFESTING DOMESTIC CATTLE OF KERALA(COLLEGE OF VETERINARY AND ANIMAL SCIENCES POOKODE, LAKKIDI, 2022-04-01) PRABODH KUMAR HEMBRAM; Reghu RavindranThe tick-borne diseases cause heavy economic losses for the livestock industry throughout the world. The transovarial transmission is one of the most distinctive characteristics of many tick-borne pathogens. There are only very few documented reports on the transovarial transmission of the pathogens through ticks in India. The present study was carried out with the objectives of the detection of parasitic pathogens in ticks, their egg masses and larvae by polymerase chain reaction (PCR) and identification of the tick species involved in the transovarial transmission of the pathogens in Kerala. In the present study, the molecular technologies such as polymerase chain reaction (PCR), sequencing and phylogenetic analysis were carried out. The male and female ticks were collected from northern, central and southern zones of Kerala during the study. They were morphologically identified as Rhipicephalus annulatus, R. microplus and Haemaphysalis bispinosa. A total of 140 engorged female ticks (R. annulatus-70, R. microplus- 40, H. bispinosa- 30) were kept for oviposition in a Biological Oxygen Demand (BOD) incubator at 28 °C and 85 % relative humidity. Only 90 ticks laid ova and they were further used for the study. On the 15th day of oviposition, both the female ticks and half of the eggs laid by them were stored at - 80 °C. The other half of the eggs laid by them were kept for hatching. The larvae hatched out were also transferred to -80 °C. The genomic DNA was extracted from the female ticks, their egg masses and larvae and utilized as the template for the polymerase chain reactions. The PCR amplifying a ~460 bp V4 region of 18S rRNA gene-specific for Babesia spp. and Theileria spp. revealed amplification in R. annulatus ticks (30), egg masses (24) and larvae (24) respectively. Using them, ~758 bp rhoptry associated protein-1a (rap-1a) gene of B. bigemina was amplified in R. annulatus ticks (19), their egg masses and larvae. The current study thus, provided the molecular evidence for transovarial transmission of B. bigemina in R. annulatus. Interestingly, the PCR amplification of the TRAP gene (~855 bp) specific for B. gibsoni was also detected in R. annulatus ticks (5) engorged on cattle, their egg masses and larvae. The ~776 bp major piroplasm surface protein (MPSP) gene specific for Theileria orientalis was amplified in engorged R. annulatus ticks (6), however, none of their egg masses and larvae showed amplification. Similarly, the polymerase chain reactions specific for the amplification of the apical membrane antigen-1 (AMA-1) and β-tubulin gene of B. ovata and major merozoite surface protein of T. annulata failed to amplify the respective products in any of the samples. An ~854 bp product specific for major surface protein 4 (msp4) gene of A. marginale could be amplified in R. annulatus ticks (7), their egg masses and larvae. In addition, a ~641 bp product specific for the 16S rRNA gene of A. phagocytophilum was amplified in H. bispinosa (8) and R. annulatus (6) ticks, their egg masses and larvae. However, the PCR specific for the 16S rRNA gene of A. bovis did not amplify the ~551 bp product in any of the ticks, their egg masses and larvae. The Rickettsia spp. was detected from H. bispinosa (6) and R. annulatus (4) ticks, their egg masses and larvae by the nested PCR amplification of ~381 bp fragment specific for the citrate synthase (gltA) gene. A ~549 bp fragment specific for the 17-kDa common antigen gene (htrA) of Rickettsia spp. was amplified only from H. bispinosa ticks (6), their egg masses and larvae. The Rickettsia spp. detected in this study was identified as closely related to the R. raoultii when the PCR product was sequenced for phylogenetic analysis. The species of all the ticks positive for haemoparasites were further confirmed by PCR amplification of mitochondrial 16S rRNA, 18S rRNA and mitochondrial cytochrome oxidase 1 (COI) gene specific for ticks. The present investigation thus confirmed, the transovarial transmission of B. bigemina, B. gibsoni, A. marginale, A. phagocytophilum and a Rickettsia spp. closely related to R. raoultii through R. annulatus and A. phagocytophilum and the Rickettsia spp. closely related to R. raoultii through H. bispinosa ticks. In addition, the mixed infections with B. bigemina and A. phagocytophilum, B. bigemina and A. marginale, B. gibsoni and A. marginale were detected in R. annulatus ticks.ThesisItem Open Access MOLECULAR CHARACTERISATION AND SERO- DETECTION OF BABESIA GIBSONI IN DOGS OF KERALA(COLLEGE OF VETERINARY AND ANIMAL SCIENCES POOKODE, WAYANAD, 2022-03-25) DEEPA C.K.; Reghu RavindranCanine babesiosis is an important tick-borne disease caused by intraerythrocytic piroplasms of the genus Babesia, which affect the domestic and wild canines. The prevalence of canine babesiosis due to Babesia gibsoni has increased throughout the world including the south Indian state of Kerala. Hence, the present study was undertaken with the following objectives, molecular characterisation of B. gibsoni in dogs of Kerala by polymerase chain reaction (PCR); sequencing, cloning and expression of thrombospondin-related adhesive protein (BgTRAP) gene of B. gibsoni; sero- detection of B. gibsoni antibodies in dogs by indirect enzyme-linked immunosorbent assay (ELISA) using the recombinant antigen. Thin peripheral blood smears (n=297) collected from dogs of three different zones of Kerala (north, south and central), revealed the presence of piroplasms of B. gibsoni in 60 samples by microscopy. The DNA isolated from the whole blood samples of the same number of animals were used for the molecular detection of B. gibsoni using PCR assays targeting amplification of different genes. The genus specific primers targeting 18S rRNA gene of Babesia spp. amplified ~1665 bp fragment in 72 samples during the primary PCR while, a ~308 bp B. gibsoni specific product was amplified in 120 samples in nested PCR using another set of primers amplifying its internal region. The polymerase chain reaction targeting the thrombospondin related adhesive protein gene of B. gibsoni revealed the amplification of ~855 bp product in 125 samples. The amplification of apical membrane antigen (AMA1) gene specific for B. gibsoni showed ~1483 bp in 65 samples. Amplicons of ~1500 bp, ~825 bp and ~1938 bp were observed in 50, 85 and 60 samples when they were targeted against B. gibsoni specific genes like secreted antigen 1 (SA1), 50 kDa surface antigen (P50), heat shock protein (HSP70) respectively. Hence, the PCR assays targeting the 18 S rRNA (nested) and TRAP were identified as highly useful assays for the diagnosis of canine babesiosis due to B. gibsoni. There was no significant difference in the relative effectiveness between BgTRAP PCR and nested Bg18S rRNA PCR for the detection of B. gibsoni in canines based on McNemar’s test (P>0.05). The single step BgTRAP PCR was less time consuming, compared to the nested time consuming Bg18S rRNA PCR. Few amplicons of these PCR assays were randomly selected for sequencing. The phylogenetic analysis of Bg18S rRNA and BgHSP70 sequences, revealed the clustering of all isolates of B. gibsoni in a single clade revealing the close genetic relatedness among the isolates of Kerala and those from other countries. The phylogeny of BgTRAP and BgP50 genes revealed the clustering of the isolates from Indian subcontinent, differentiating them from similar isolates from East Asian countries. Similarly, based on phylogeny of BgAMA1 sequences, it was observed that the Japanese isolates were clustered separately from all other available isolates including those from India. Hence, it was concluded that the genetic diversity is very minimum among B. gibsoni isolates. In order to develop a serological screening assay for the detection of B. gibsoni, the prokaryotic expression of the thrombospondin-related adhesive protein (BgTRAP) was also performed in the present study. The N-terminal BgTRAP gene fragment was cloned into prokaryotic expression vector (pET32a) and transformed into BL21 Escherichia coli cells. The recombinant protein was purified and used for the indirect ELISA. The recombinant protein detected sero-reactivity in 125 (46.12 per cent) out of 271 samples. There were no cross-reactivity for this ELISA with the known positive sera of the dogs infected with the helminths like, Ancylostoma caninum, Dirofilaria immitis, D. repens, Spirometra spp., Toxocara canis and haemoprotozoans like Trypanosoma evansi, B. vogeli, Hepatozoon canis and Ehrlichia canis. The newly standardised rBgTRAP ELISA when analysed for the relative effectiveness using McNemar's test against both BgTRAP PCR and nested Bg18S rRNA PCR, no significant difference was observed. The sensitivity and specificity of rBgTRAP ELISA in comparison with BgTRAP PCR as the reference test, was 84.00 and 73.33 per cent respectively. When the Kappa statistics was used for the evaluation of agreement of the newly standardised rBgTRAP- ELISA with reference test BgTRAP PCR, the newly developed ELISA showed fair to good agreement for the detection of B. gibsoni organism in dogs (Kappa value=0.566). Hence, the indirect ELISA using the recombinant BgTRAP antigen could be considered as an adjunct tool for the surveillance of B. gibsoni infection in dogs.ThesisItem Open Access MOLECULAR DETECTION OF HAEMOPROTOZOAN AND HAEMORICKETTSIAL ORGANISMS IN COMMUNITY OWNED DOGS OF KERALA(COLLEGE OF VETERINARY AND ANIMAL SCIENCES POOKODE, 2022-02-11) GATCHANDA SHRAVAN KUMAR; Anju VargheseIndia's diverse climatic zones are ideal for a wide range of vectors and pathogens. Most of the community/stray dogs suffers from a variety of diseases due to malnutrition and lack of basic health care. Stray dogs are thought to be suitable reservoirs of several zoonotic parasites. The objective of the present study was to detect haemoprotozoans and haemorickettsial organisms from community owned dogs of Kerala. A total of (n=150) peripheral blood smears and whole blood samples were collected from community owned dogs from different zones of Kerala. The peripheral blood smear examination revealed prevalence of 21.33 per cent and 8 per cent for Babesia gibsoni and B. vogeli infection by microscopy. None of the blood smears were positive for any other haemoparasites. The genomic DNA was extracted from all the blood samples and used as a template for detection of haemoprotozoan and haemeorickettsial organisms. The B. gibsoni genus specific primer targeting 18S rRNA showed an amplicon size of ~1655 bp length in 61 samples (40.67 per cent) by primary PCR. The PCR product of primary PCR was utilized as a template for nested PCR using a set of internal primers and amplified a ~308 bp fragment of 18S rRNA gene in 87 samples (58 per cent). The polymerase chain reaction targeting B. gibsoni TRAP gene showed an amplification at ~855 bp size in 90 samples (60 per cent). The PCR amplification of B. vogeli and Hepatozoon canis targeting 18S rRNA gene showed an amplicon size of ~590 bp length in 59 samples (39.33 per cent) and 666 bp length in 42 samples (28 per cent) respectively. Trypanosoma evansi was positive in 41 samples (27.33 per cent) using T. evansi specific RoTat 1.2 gene giving out a product size of ~205 bp. Only a single sample showed PCR amplification for Ehrlichia canis VirB9 and gp-200 genes with amplicon sizes of ~380 bp and ~1286 bp respectively. Amplification at ~678 bp length by PCR targeting 16S rRNA gene of Aanaplasma platys was obtained only in one sample. Among canine vector borne diseases in community owned dogs of Kerala, B. gibsoni was highly prevalent followed by B. vogeli, H. canis, T. evansi, E. canis and A. platys. Mixed infection of B. gibsoni with other haemoprotozoans and haemorickettsiales was recorded from all zones of Kerala with a high co-infection of B. gibsoni and B. vogeli (32.67 per cent) followed by B. gibsoni and H. canis (18 per cent). Selected amplicons of B. gibsoni, B. vogeli, H. canis, T. evansi, E. canis and A. platys were sequenced. The phylogenetic analysis based on 18S rRNA gene of B. gibsoni and H. canis, 16S rRNA gene of A. platys and VirB9 and gp-200 gene of E. canis does not showed any genetic diversity. However, the phylogenetic analysis of TRAP gene of B. gibsoni sequences indicated that B. gibsoni field isolates of Kerala in the present study formed a single clade with other Indian and Bangladesh isolates and separated away from East Asian countries. Thus, the isolates of B. gibsoni from Indian subcontinent are genetically unique compared to other Asian isolates showing a maximum genetic diversity. The phylogenetic analysis based on 18S rRNA gene of B. vogeli indicated that the B. vogeli isolates circulating in pet and community owned dogs of Kerala and other parts of India are genetically different from other Babesia spp. isolates from other countries, indicating two lineages of B. vogeli in the world. The phylogenetic analysis of T. evansi using RoTat 1.2 gene showed that the isolates from dogs formed a monophyletic clade with the T. evansi isolates from Buffalo of India and Indonesia. The high nucleotide variation with in our sequences may be the possible attributes for showing the high genetic diversity within T. evansi population from other countries and different hosts. Data from the current study suggest that the tick- borne pathogens are highly prevalent among community owned dogs of Kerala. The hot and humid climatic conditions of Kerala is congenial for the survival of ticks and tick- borne pathogens. The difference in prevalence in the present study from community owned dogs and pet dogs could be due to area of sample collection, sample size, the type of dogs screened and selection of clinically suspected samples from pet dogs. In the present study, blood samples have been collected from community owned dogs from Animal Birth Control Centres (ABCs) and not from clinically suspected hospital cases for different haemoprotozoan organisms. The 129 present study formed the first and foremost prevalent study of haemoparasites in community owned dogs of Kerala.ThesisItem Open Access EFFECTS OF COMBINATION OF SYNERGISTS WITH CRUDE ETHANOLIC HERBAL EXTRACTS OF CLERODENDRUM PHILIPPINUM AND LEUCAS LAVANDULIFOLIA AGAINST RHIPICEPHALUS (BOOPHILUS) ANNULATUS(COLLEGE OF VETERINARY AND ANIMAL SCIENCES POOKODE, 2022-02-15) PRASHANT S KURBET; Ajith Kumar K.GThe objective of the present study was to compare the anti-tick activity due to addition of the synergists viz., piperonyl butoxide (PBO) and S, S, S-tributyl phosphotrithioate (DEF) with crude ethanolic extract of Clerodendrum philippinum and Leucas lavandulifolia against Rhipicephalus (Boophilus) annulatus and to evaluate the effects of these treatments on the reproductive organs of R. (B.) annulatus L. lavandulifolia (Family: Lamiaceae) and C. philippinum Schauer (Family: Verbenaceae) are generally annual spreading herbs seen in cultivated fields, wastelands and roadsides throughout India. Acaricidal effects of these plants were reported earlier. In order to increase the acaricidal activity, inhibition of fecundity and inhibition of hatching of eggs laid by treated ticks, the synergists like piperonyl butoxide (PBO), S, S, S-tributyl phosphotrithioate (DEF) and tripheny phosphate (TPP) were added along with crude ethanolic extracts of L. lavandulifolia and C. philippinum at a ratio of 0.5:1. The addition of TPP, PBO and DEF to the crude ethanolic extract of L. lavandulifolia increased the adult tick mortality to 2.95, 2.95 and 0.51-fold respectively. In addition, the inhibition of fecundity increased 2.00, 1.98 and 1.65 times after addition of these synergists to the crude extract. The addition of TPP, PBO and DEF to the crude ethanolic extract of C. philippinum increased the adult tick mortality 1.90, 1.77 and 1.36 fold respectively. The inhibition of fecundity also increased 1.56, 1.54 and 1.49 times respectively. The present investigation revealed that the synergists TPP and PBO were the ideal synergists for producing adulticidal effects when combined with crude ethanolic extracts. The effect of extracts, sysnergists and synergised extracts were testedagainst the larvae of R. (B.) annulatus using larval packet test (LPT). The extracts of L. lavandulifolia alone exhibited larval mortality of 1.81 per cent at 1.1 per cent(IFD50) concentration. Similarly, at 0.55 per cent PBO, DEF and TPP exhibited 33.41, 88.57 and 33.58 per cent larval mortality. The highest larval mortality (99.09 ± 0.91 per cent) was seen when 1.1 per cent L. lavandulifolia synergised with 0.55 per cent DEF, PBO and TPP synergized extracts caused 97.66 ± 0.78 per cent and 71.97± 3.70 per cent mortality respectively. The crude ethanolic extract of C philippinum alone exhibited larval mortality of 0.36 ± 0.36 per cent at 0.4 per cent (IFD50 concentration). Similarly, when synergist alone was tested at 0.20 per cent concentration each, DEF, PBO and TPP exhibited 92.50, 76.94, and 0.00 per cent larval mortality respectively. The highest larval mortality (93.71 ± 2.00per cent) was seen when 0.4 per cent C. philippinum synergised with 0.2 per cent DEF. However, the larval mortality induced by the DEF synergised extract did not significantly increase when compared with DEF alone. Though PBO synergized extract also caused significantly high mortality, it was only 26.49 ± 7.37 per cent. However, TPP synergized extract of C. philippinum could not induce any larval mortality. Larval mortality caused by L. lavandulifolia. extract increased 39.76, 53.95 and 55.10 fold after addition of TPP, PBO and DEF respectively. Similarly, larval mortality caused by C. philippinum. extract also increased 0.00, 73.58 and 260.30-fold respectively. Hence, DEF was identified as better synergist causing larvicidal activity in combination with crude ethanolic plant extracts. Histological changes observed in the oocytes of ticks treated with synergized extract were reduction in size of oocytes, reduced basophilia of type I oocytes, vacuoles in the cytoplasm, reduced the amount of yolk granules, irregular shape, presence of vacuoles in the germ vesicle, decrease in the content of yolk droplets. Possible acaricidal bioactive molecules identified using GC-MS analysis in the crude ethanolic extracts of L. lavandulifolia and C. philippinum were benzaldehyde, caryophyllene, Octadec-9-enoic acid and hexadecanoic acid.ThesisItem Open Access SEROLOGICAL AND MOLECULAR DETECTION OF TOXOPLASMA GONDII ASSOCIATED WITH ABORTIONS IN GOATS(COLLEGE OF VETERINARY AND ANIMAL SCIENCES MANNUTHY, THRISSUR, 2021-12-30) KARTHIKA R.; K. DevadaToxoplasmosis, a cosmopolitan zoonotic parasitic infection prevalent throughout the world affects all warm blooded animals and man. Although the presence of parasites do not lead to fatal events, its impact on the goat population has become a concern among the farmers. The present study was undertaken to determine the prevalence of Toxoplasma gondii in recently aborted goats from the central districts of Kerala viz., Thrissur, Palakkad and Ernakulam. In the study, a total of 72 blood samples, 108 foetal tissues from 27 aborted foetuses, and 25 milk samples from recently aborted goats and from those with a history of abortion were collected during a period from November 2019 to November 2020. Impression smears were also prepared from the foetal tissues and examined. The samples collected were subjected to different methods such as microscopy, ELISA and PCR for the detection of various developmental stages of T. gondii. Milk samples and impression smears were examined by Giemsa staining microscopically for parasitic stages of Toxoplasma but none of them revealed the presence of the organism. Seventy two serum samples were subjected to ELISA for the detection of IgG antibodies of T. gondii. The overall seroprevalence was determined to be 56.94 per cent. A higher prevalence was observed in goats above four years of age and in those that were let out for grazing. It was also observed that majority of the abortions occurred in the second stage of gestation in goats that were detected as positive by ELISA. Serum samples collected from 27 goats in which a recent abortion had taken place collected from Thrissur showed antibodies in 14 samples by ELISA (51.85 per cent). Tissues such as heart, brain, liver and placenta collected from three of the aborted foetuses from the same goats were simultaneously positive for B1 gene of T. gondii in PCR, the molecular prevalence being 11.11 percent. Toxoplasma gondii DNA was also detected in the foetal tissues of one of the goats that was detected as negative by ELISA. The same samples used for T. gondii detection were used for the detection of NC-5 gene of Neospora caninum in the aborted foetal tissues and they revealed a molecular occurrence of 7.40 per cent. Analysis of the sequences obtained from positive DNA of T. gondii and N. caninum using BLAST demonstrated 100 per cent homology. District–wise prevalence revealed relatively higher prevalence in Ernakulam district (62.5 per cent) compared to Thrissur (56.09 per cent) and Palakkad (53.33 per cent), even though the difference was not significantThesisItem Open Access ASSOCIATION OF TEMPERATURE HUMIDITY INDEX WITH PHYSIOLOGICAL, BIOCHEMICAL, AND BEHAVIOURAL RESPONSES IN NATIVE AND CROSSBRED GOATS(COLLEGE OF VETERINARY AND ANIMAL SCIENCES MANNUTHY, THRISSUR, 2020-11-30) DEBIA YAMIN; V. BeenaThe present study was undertaken to investigate the association of temperature humidity index with physiological, biochemical and behavioural responses in Malabari, crossbred and Attappady goats of Kerala. The research work was conducted at University Goat and Sheep Farm, KVASU, Mannuthy, Thrissur district in Kerala from March to May, 2020. In-house temperature, in house relative humidity and physiological parameters were measured at 7.00 AM, 10.00 AM, 2.00 PM and 5.00 PM. Haematological, biochemical and endocrines parameters, blood gases and electrolytes, were analysed during 2 nd, 32nd day and 60th day of the study. A positive correlation was noticed between in-house temperature (IT) and temperature humidity index (THI) with respiration rates, rectal temperatures, heart rate and skin temperature levels of breeds at 2.00 PM and 5.00 PM. Alterations in physiological parameters were more significant in Malabari goats. However a negative correlation was observed between in-house relative humidity and all physiological parameters during all the different times. Behavioural patterns were influenced by increased IT and THI and the breeds spent more time in standing position during heat stress. No significant difference was observed in haematological parameters in the breeds except in TLC levels which were significantly increased during periods of heat stress. A significant difference was observed within the study period in the pO2, Na+ , HCO3 - and blood pH. A significant difference was observed between the breeds for K + , Cl and HCO3 - levels. No significant difference was noticed for pCO2 level among the breeds and within the observed days. A significantly higher glucose level on 32nd day and a lower total cholesterol level in the latter half of the experimental period were noticed in Malabari and crossbred. Mean total protein levels of all the breeds were significantly increased on 32 nd day. The albumin, globulin and A/G ratio levels of all the breeds were within the range during the period of study. Increased GGT levels were observed in the first half of the experimental period in all breeds. Higher cortisol levels in Malabari and crossbred could be estimated in the first half of the experiment. Although Malabari showed higher T3 levels on 32nd day compared to other breeds, within the breeds no significant difference in T3 levels could be noticed. However, significantly higher T4 values were recorded on 32nd day and 60th day only in crossbred breeds when the IT and THI were high.ThesisItem Open Access FORMULATION OF A COMBINED TARGETED SELECTIVE TREATMENT STRATEGY FOR SUSTAINABLE CONTROL OF GASTRO INTESTINAL NEMATODOSIS IN GOATS(COLLEGE OF VETERINARY AND ANIMAL SCIENCES, MANNUTHY, THRISSUR, 2020-12-18) K. SYAMALA; K. DevadaGastro intestinal parasitism and mounting anthelmintic resistance pose serious impediments to goat production in humid tropical state of Kerala. In order to develop a sustainable parasitic control strategy ideal for goats of the state, a comprehensive research on epidemiology of gastro-intestinal parasitism, parasitological indicators and helminth control modules was carried out with the following objectives; 1) conduct a survey on epidemiology and current treatment strategies of gastro-intestinal parasitism among goats in Kerala; 2) validate the combined targeted selective treatment (C-TST) indicators such as FAMACHA©, body condition score (BCS) and dag score (DS); 3) compare the impact of treatment strategies like routine anthelmintic treatment (RT), strategic prophylactic treatment (SPT) and C-TST on the growth performance and anthelmintic resistance in goats; and 4) develop an anaemia eye colour chart based on the physiological status suitable for goats in humid tropics. Detailed survey on veterinary practitioners in Kerala on their awareness on parasite control practices revealed that updates on advances in veterinary parasitology in relation to dose calculation, development and management of anthelmintic resistance and alternate methods of parasite control with limited chemotherapy need to be intensified. A glance into the parasite management strategies followed by the goat farmers of Kerala indicated that majority of them were clueless of the importance of correct dosage, frequency of anthelmintic treatment and integrated parasite management methods. Epidemiological survey of gastro-intestinal parasitism in goats in the state was carried out in 13 agro-ecological zones for a period of one year in six organised farms and 120 small holder flocks. It revealed an overall prevalence of 67.2 per cent strongylosis with a mean faecal egg count (FEC) of 390.79 ± 19.17, ranging from 0 to 8968 and standard deviation of 716.745. Highly significant influence of season and month (p 3, BCS was ≤ 1.5, dag score was ≥ 2 and/ or FEC >500. In the case of routine treatment bimonthly anthelmintic treatment was carried out whereas in the case of strategic prophylactic treatment (SPT) anthelmintic treatment was given before South West monsoon (June) and after North East monsoon (October). After 13 months of treatment, the impact of the C-TST on parasitological and production parameters and mortality was assessed. More number of doses (256) were required for the RT while for SPT only 152 doses were required for administration. The least number of doses (82) only were given to animals in C TST, where treatment was applied based on the TST indicators. The impact of the C-TST on anthelmintic resistance was assessed by FECRT and molecular methods, and no statistically significant difference was detected before and after treatment and between the treatment groups. There was no significant difference in prolificacy, weight gain and mortality between C-TST and the other two treatment regimes. . Molecular genotyping of Haemonchus contortus by PCR-RFLP revealed the presence of polymorphism at 198 and 200 codons, while at codon 167 no heterozygous genotype were detected. In Trichostrongylus sp. F200Y polymorphism was identified in isotype 1-β tubulin, whereas at codon 167 only resistant genotypes were detected. The gene frequency was 0.16 for resistant allele before treatment and 0.14 after treatment. In this species, no polymorphism was detected at E198A in all the treatment categories. The most frequently identified polymorphism in H. contortus was associated with E198A, while F200Y was found to be the least common. In Trichostrongylus sp., F200Y was found to be the most common. No significant difference could be observed between the genotype frequencies at the three codons in the two species of strongyle parasites before and after treatments.
