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herd-level prevalence of selected endemic infectious diseases of dairy cows in great britain.to implement appropriate and effective disease control programs at the national level, up-to-date and unbiased information on disease frequency is needed. the aim of this study was to estimate the prevalence of selected endemic infectious diseases in the population of dairy herds in great britain. bulk milk tank (bmt) samples from 225 randomly selected dairy farms, stratified by region and herd size, were tested for antibodies against bovine viral diarrhea virus (bvdv), bovine herpesvirus type 1 ...201728843682
anthelmintic effects of forage chicory (cichorium intybus) against free-living and parasitic stages of cooperia oncophora.chicory shows great promise as an anthelmintic forage for grazing ruminants that can reduce reliance on anti-parasitic drugs. recently, we reported potent anthelmintic effects of chicory-based diets in infected cattle with significant reductions in worm burdens of the abomasal nematode ostertagia ostertagi, whilst no apparent activity was observed against the small intestinal parasite cooperia oncophora. to explore this discrepancy, we investigated direct anthelmintic effects of forage chicory a ...201728807295
establishment rate of cattle gastrointestinal nematodes in farmed red deer (cervus elaphus).red deer can be infected with some gastrointestinal nematodes (gin) of cattle but it is unknown to what extent. an indoor study was conducted to determine the establishment rate of cattle gin in young deer. five young calves and 5 young red deer were used. they were effectively treated with anthelmintics when housed and then infected 2 weeks later. after four weeks they were killed for total worm counts. establishment rates were assessed comparing worm counts to the infective dose which were ide ...201728807276
the use of nemabiome metabarcoding to explore gastro-intestinal nematode species diversity and anthelmintic treatment effectiveness in beef calves.next-generation deep amplicon sequencing, or metabarcoding, has revolutionized the study of microbial communities in humans, animals and the environment. however, such approaches have yet to be applied to parasitic helminth communities. we recently described the first example of such a method - nemabiome sequencing - based on deep-amplicon sequencing of internal transcribed spacer 2 (its-2) rdna, and validated its ability to quantitatively assess the species composition of cattle gastro-intestin ...201728797791
[anthelmintic resistance in ruminants: development, diagnostics, and procedures].anthelmintic resistance of gastrointestinal nematodes in small ruminants, but also in cattle and horses, is now found worldwide. the reason for increasing anthelmintic resistance is, in particular, the extensive use of all the anthelmintic agents available on the market. a non-targeted use leads to the selection of naturally occurring resistance genes within parasite populations. the most practical method for evaluating the efficacy of an anthelmintic is the fecal egg-count reduction test. to re ...201728765867
economic assessment of ostertagia ostertagi and fasciola hepatica infections in dairy cattle herds in germany using paracalc(®).the aim of the current study was to estimate economic costs of ostertagia ostertagi and fasciola hepatica infections in dairy cattle herds in germany using the online calculation programme paracalc(®). following a questionnaire, survey data were available from 464 farms in 14 federal states. on those farms bulk tank milk (btm) samples and additionally up to six serum samples collected from first season grazing calves were analysed, using a commercially available elisa (boehringer ingelheim svano ...201728576343
unusual population genetics of a parasitic nematode: mtdna variation within and among populations.very little is known about the distribution of genetic variance within and among populations of parasitic helminths. in this study we used mitochondrial dna (mtdna) restriction fragment analysis to describe the population genetic structure of ostertagia ostertagi, a nematode parasite of cattle, in the united states. estimates of within-population mtdna diversity are 5 to 10 times greater than typical estimates reported for species in other taxa. although populations are genetically differentiate ...199228564029
characterization of a novel aspartyl protease inhibitor from haemonchus contortus.aspartyl protease inhibitor (api) was thought to protect intestinal parasitic nematodes from their hostile proteolytic environment. studies on ostertagia ostertagi, ascaris suum and brugia malayi indicated that aspins might play roles in nematode infection. in a recent study, proteins differentially expressed between free-living third-stage larvae (l3) and activated l3 (xl3) of haemonchus contortus were identified by 2d-dige. api was found downregulated in xl3 when compared with l3. however, the ...201728420411
modelling the impacts of pasture contamination and stocking rate for the development of targeted selective treatment strategies for ostertagia ostertagi infection in calves.a simulation study was carried out to assess whether variation in pasture contamination or stocking rate impact upon the optimal design of targeted selective treatment (tst) strategies. two methods of tst implementation were considered: 1) treatment of a fixed percentage of a herd according to a given phenotypic trait, or 2) treatment of individuals that exceeded a threshold value for a given phenotypic trait. four phenotypic traits, on which to base treatment were considered: 1) average daily b ...201728408216
characterization of ostertagia ostertagi annexin-like proteins at different developmental stages.ostertagiosis remains an economically important parasitic disease in cattle in the temperate regions of the world. repeated exposures to ostertagia ostertagi in calves cause significant pathology in the abomasum but elicit little protective immunity. the larvae use the host's gastric glands as a niche for development, where the parasite completes its parasitic stages, while in the gastric glands, the larvae must down-regulate the host inflammatory immune responses. annexin (anx) a1, commonly fou ...201728378195
economic modelling of grazing management against gastrointestinal nematodes in dairy cattle.grazing management (gm) interventions, such as reducing the grazing time or mowing pasture before grazing, have been proposed to limit the exposure to gastrointestinal (gi) nematode infections in grazed livestock. however, the farm-level economic effects of these interventions have not yet been assessed. in this paper, the economic effects of three gm interventions in adult dairy cattle were modelled for a set of flemish farms: later turnout on pasture (gm1), earlier housing near the end of the ...201728288768
a multi-country study to assess the effect of a treatment with moxidectin pour-on during the dry period on milk production in dairy cows.a randomized clinical study was conducted in a total of 45 commercial dairy farms in france (14 farms), germany (28 farms) and the uk (3 farms) to evaluate the effect of an anthelmintic treatment on milk yield in the subsequent lactation. a total of 1287 animals with suspected exposure to ostertagia ostertagi were included in the study. animals were treated during the dry period (7-77days before parturition) with moxidectin pour-on (cydectin(®) 0.5% pour-on, zoetis; 638 animals) or left untreate ...201728259556
condensed tannins in the gastrointestinal tract of cattle after sainfoin (onobrychis viciifolia) intake and their possible relationship with anthelmintic effects.condensed tannins' (cts) fate along the digestive tract of ruminants may account for the variable efficacy of cts against gastrointestinal nematodes. we analyzed cts in the digesta of cattle fed sainfoin. with the acetone-butanol-hcl assay, the total cts concentrations in the digesta were close to those in the diets (6.3 and 1.5% of dm in experiments 1 and 2, respectively); thus, cts remained potentially largely undegraded/unabsorbed. with the thiolysis assay, cts concentration was much higher i ...201728120611
modelling the consequences of targeted selective treatment strategies on performance and emergence of anthelmintic resistance amongst grazing calves.the development of anthelmintic resistance by helminths can be slowed by maintaining refugia on pasture or in untreated hosts. targeted selective treatments (tst) may achieve this through the treatment only of individuals that would benefit most from anthelmintic, according to certain criteria. however tst consequences on cattle are uncertain, mainly due to difficulties of comparison between alternative strategies. we developed a mathematical model to compare: 1) the most 'beneficial' indicator ...201627915061
climate influences assemblages of abomasal nematodes of sheep on steppe pastures in the east of algeria.it is a common view that assemblages of parasitic nematodes are influenced by climatic conditions; however, there are only a few articles available regarding those that infect farm animals. we investigated the relationship between climate variables and infection with abomasal trichostrongyles in 335 1-year-old rams grazed on steppe pastures in eastern algeria. abomasa were collected from 12 local slaughterhouses located in four climatic areas (from humid to arid) and the worms extracted, identif ...201627905269
efficacy of ivermectin against gastrointestinal nematodes of cattle in denmark evaluated by different methods for analysis of faecal egg count reduction.the efficacy of ivermectin (ivm) against gastrointestinal nematodes in danish cattle was assessed by faecal egg count reduction test (fecrt). six cattle farms with history of clinical parasitism and avermectin use were included. on the day of treatment (day 0), 20 naturally infected calves per farm (total n = 120) were stratified by initial faecal egg counts (fec) and randomly allocated to a treatment group dosed with 0.2 mg ivm kg(-1) body weight s.c. (ivm; n = 10) or an untreated control group ...201627835769
confirmation of ivermectin resistance in ostertagia ostertagi in cattle in new zealand.six suspected cases of ivermectin resistance in ostertagia spp. in cattle were investigated after routine anthelmintic efficacy testing on commercial farms. on four farms a comprehensive faecal egg count reduction test (fecrt) was undertaken using oral formulations of ivermectin (0.2mg/kg), albendazole (10mg/kg) and levamisole (7.5mg/kg) while on two farms only ivermectin was tested. the proportions of ostertagia spp. in the untreated control and post-treatment larval cultures were used to appor ...201627809969
abomasal mucosal immune responses of cattle with limited or continuous exposure to pasture-borne gastrointestinal nematode parasite infection.it has been well documented that cattle raised on pasture are slow in weight gain when compared to those fed with grain. inflammation in the digestive system commonly caused by pasture-transmitted gastrointestinal (gi) nematode parasites that could negatively impact feed conversion has never been compared in cattle raised with no pasture exposure (npe, uninfected), limited pasture exposure (lpe, exposure until weaning), or continuous pasture exposure (cpe, life time exposure). in the present stu ...201627809966
climate-driven longitudinal trends in pasture-borne helminth infections of dairy cattle.helminth parasites of grazing ruminants are highly prevalent globally and impact negatively on animal productivity and food security. there is a growing concern that climate change increases helminth disease frequency and intensity. in europe, these concerns stem from case reports and theoretical life cycle models assessing the effects of climate change scenarios on helminth epidemiology. we believe this study is the first to investigate climate-driven trends in helminth infections of cattle on ...201627771256
a stochastic model to investigate the effects of control strategies on calves exposed to ostertagia ostertagi.predicting the effectiveness of parasite control strategies requires accounting for the responses of individual hosts and the epidemiology of parasite supra- and infra-populations. the first objective was to develop a stochastic model that predicted the parasitological interactions within a group of first season grazing calves challenged by ostertagia ostertagi, by considering phenotypic variation amongst the calves and variation in parasite infra-population. model behaviour was assessed using v ...201627573532
the efficacy and plasma profiles of abamectin plus levamisole combination anthelmintics administered as oral and pour-on formulations to cattle.in phase i, faecal egg count reduction tests (fecrt) were conducted on six commercial cattle farms to compare the performance of two pour-on and one oral combination anthelmintic. groups of 12-15 calves were sampled for faecal nematode egg count (fec) before treatment with either abamectin oral, levamisole oral, an abamectin+levamisole oral combination or one of two abamectin+levamisole combination pour-ons. samples were collected again 14days after treatment to calculate the percentage reductio ...201627523943
a simulation model to investigate interactions between first season grazing calves and ostertagia ostertagi.a dynamic, deterministic model was developed to investigate the consequences of parasitism with ostertagia ostertagi, the most prevalent and economically important gastrointestinal parasite of cattle in temperate regions. interactions between host and parasite were considered to predict the level of parasitism and performance of an infected calf. key model inputs included calf intrinsic growth rate, feed quality and mode and level of infection. the effects of these varied inputs were simulated o ...201627514906
host protective asp-based vaccine against the parasitic nematode ostertagia ostertagi triggers nk cell activation and mixed igg1-igg2 response.the mucus-dwelling parasite ostertagia ostertagi is one of the most important gastrointestinal nematodes in cattle. our group has previously demonstrated the protective capacity of a vaccine against this parasite based on a native activation-associated secreted protein asp1 (nasp) in combination with the saponin adjuvant quila. the aim of the current study was to analyse the effect of both antigen and adjuvant on the cellular and humoral vaccine-induced immune responses by comparing the native a ...201627403891
explaining variability in first grazing season heifer growth combining individually measured parasitological and clinical indicators with exposure to gastrointestinal nematode infection based on grazing management practice.the objective of our study was to explain the variability of average daily weight gain (adwg) due to gastrointestinal nematode (gin) infection for 291 non treated first grazing season (fgs) heifers, from 12 independent groups in the western part of france, by combining parasitological and clinical indicators at individual level and grazing management indicators at group level. parasitological indicators were faecal egg count (fec), anti ostertagia ostertagi antibody level (ostertagia odr), and p ...201627369576
the level of embryonation influences detection of ostertagia ostertagi eggs by semi-quantitative pcr.the internal transcribed spacer 2 (its2) is a candidate diagnostic marker of the pathogenic cattle nematode ostertagia ostertagi. the aims of this study were: (i) to document and quantify how the development of o. ostertagi eggs affects its2 copies under different storage conditions, and (ii) to suggest optimal storage conditions for faecal samples in a diagnostic pipeline that involves detection and semi-quantification by real-time semi-quantitative polymerase chain reaction (qpcr).201627357701
anti-parasitic activity of pelleted sainfoin (onobrychis viciifolia) against ostertagia ostertagi and cooperia oncophora in calves.increasing anthelmintic-resistance in nematodes of ruminants emphasises the need for sustainable parasite control. condensed tannin-containing legume forages such as sainfoin (onobrychis viciifolia) have shown promising anthelmintic properties in small ruminants but this has never been explored in cattle. therefore, our aim was to examine the efficacy of sainfoin against cattle nematodes in vivo.201627283323
anthelmintic effects of forage chicory (cichorium intybus) against gastrointestinal nematode parasites in experimentally infected cattle.two experiments studied the effects of dietary chicory against gastrointestinal nematodes in cattle. in experiment (exp.) 1, stabled calves were fed chicory silage (chi1; n = 9) or ryegrass/clover hay (ctl1; n = 6) with balanced protein/energy intakes between groups. after 16 days, all calves received 10 000 ostertagia ostertagi and 66 000 cooperia oncophora third-stage larvae (l3) [day (d) 0 post-infection (p.i.)]. in exp. 2, calves were assigned to pure chicory (chi2; n=10) or ryegrass/clover ...201627173405
sesquiterpene lactone containing extracts from two cultivars of forage chicory (cichorium intybus) show distinctive chemical profiles and in vitro activity against ostertagia ostertagi.the study investigated direct anthelmintic effects of sesquiterpene lactones (sl)-containing extracts from forage chicory against free-living and parasitic stages of ostertagia ostertagi. freeze-dried leaves from chicory cultivars 'spadona' and 'puna ii' were extracted using methanol/water. total sl were further fractionated by solid-phase extraction and resulting extracts were characterised by high-performance liquid chromatography (hplc). o. ostertagi eggs from faeces of mono-infected calves w ...201527120066
impact of chemical structure of flavanol monomers and condensed tannins on in vitro anthelmintic activity against bovine nematodes.plants containing condensed tannins (ct) may have potential to control gastrointestinal nematodes (gin) of cattle. the aim was to investigate the anthelmintic activities of four flavan-3-ols, two galloyl derivatives and 14 purified ct fractions, and to define which structural features of ct determine the anti-parasitic effects against the main cattle nematodes. we used in vitro tests targeting l1 larvae (feeding inhibition assay) and adults (motility assay) of ostertagia ostertagi and cooperia o ...201626888630
anthelmintic resistance in gastrointestinal nematodes of dairy cattle in the macalister irrigation district of victoria.to report anthelmintic resistance in gastrointestinal nematode parasites of cattle on commercial dairy farms in the macalister irrigation district of gippsland, victoria.201626814160
[a comparative analysis of various antigenic proteins found in haemonchus contortus--a review].many innovative researches on the development and introduction of recombinant vaccines against many economically important parasites were carried out in the 20th century. research continues to hold promise with the development of immunological and molecular approaches for control of these parasites and in this regard it has already been seen that blood-sucking parasites such as haemonchus contortus and ostertagia ostertagi are susceptible to control by vaccines containing "novel" or "concealed" ...201526710767
the relation between input-output transformation and gastrointestinal nematode infections on dairy farms.efficiency analysis is used for assessing links between technical efficiency (te) of livestock farms and animal diseases. however, previous studies often do not make the link with the allocation of inputs and mainly present average effects that ignore the often huge differences among farms. in this paper, we studied the relationship between exposure to gastrointestinal (gi) nematode infections, the te and the input allocation on dairy farms. although the traditional cost allocative efficiency (c ...201626499290
anthelmintic resistance to ivermectin and moxidectin in gastrointestinal nematodes of cattle in europe.anthelmintic resistance has been increasingly reported in cattle worldwide over the last decade, although reports from europe are more limited. the objective of the present study was to evaluate the efficacy of injectable formulations of ivermectin and moxidectin at 0.2 mg per kg bodyweight against naturally acquired gastro-intestinal nematodes in cattle. a total of 753 animals on 40 farms were enrolled in germany (12 farms), the uk (10 farms), italy (10 farms), and france (8 farms). animals wer ...201526448902
comment on bloemhoff et al., 2015. prevalence and seasonality of bulk milk antibodies against dictyocaulus viviparus and ostertagia ostertagi in irish pasture-based dairy herds. vet. parasitol. 209, 108-116. 201526391821
association between dictyocaulus viviparus status and milk production parameters in dutch dairy herds.the objective of this study was to estimate the association between dictyocaulus viviparus bulk tank milk (btm) test results and milk production and milk composition parameters in adult dutch dairy cattle herds. bulk tank milk samples were collected in august and november 2013, and elisa tests were performed. two hundred btm positive (btm+) and 200 btm negative (btm-) herds were selected based on their btm test result of november 2013, obtained from a list of farms that participated in the dutch ...201526298745
applying a kinetic method to an indirect elisa measuring ostertagia ostertagi antibodies in milk.indirect enzyme-linked immunosorbent assays (elisas) are frequently run as endpoint elisas (e-elisas). however, kinetic elisas (k-elisas) have certain advantages over e-elisas. the objective of this study was to understand the relationship between e-elisa and k-elisa results. specifically, to determine whether it was possible to run both k-elisa and e-elisa on the same plate and establish an appropriate time interval for k-elisa measurements. a normalization method for k-elisa slopes (slope rati ...201526130849
resistance of gastrointestinal nematodes to the most commonly used anthelmintics in sheep, cattle and horses in spain.the objective of this study was to evaluate the status of anthelmintic resistance (ar) in ruminants and horses in spain. the efficacy of commonly used macrocyclic lactones (mls) - ivermectin (ivm) and moxidectin (mox) - was measured in sheep, cattle and horses. in addition, albendazole (abz) and levamisole (lev) were evaluated in sheep and oxibendazole (oxi) and pyrantel (pyr) in horses. efficacy was evaluated based on the difference between the arithmetic mean pre- and post-treatment faecal egg ...201526112062
development of a multiplex fluorescence immunological assay for the simultaneous detection of antibodies against cooperia oncophora, dictyocaulus viviparus and fasciola hepatica in cattle.a major constraint for the effective control and management of helminth parasites is the lack of rapid, high-throughput, routine diagnostic tests to assess the health status of individual animals and herds and to identify the parasite species responsible for these helminthoses. the capability of a multiplex platform for the simultaneous detection of three pasture associated parasite species was evaluated and compared to existing elisas.201526084663
measuring larval nematode contamination on cattle pastures: comparing two herbage sampling methods.assessing levels of pasture larval contamination is frequently used to study the population dynamics of the free-living stages of parasitic nematodes of livestock. direct quantification of infective larvae (l3) on herbage is the most applied method to measure pasture larval contamination. however, herbage collection remains labour intensive and there is a lack of studies addressing the variation induced by the sampling method and the required sample size. the aim of this study was (1) to compare ...201525913455
controlling nematodes in dairy calves using targeted selective treatments.with increasing concerns of anthelmintic resistance in cattle nematode populations worldwide, there is a need to explore alternative approaches to nematode control. one alternative approach is the use of targeted selective treatments (tst) where only individual animals are treated instead of the entire group. this study reports the findings of a tst approach in dairy calves conducted over their first grazing season (fgs) to control both gastrointestinal nematode and lungworm challenge. ninety-si ...201525770853
rapid selection for β-tubulin alleles in codon 200 conferring benzimidazole resistance in an ostertagia ostertagi isolate on pasture.resistance to benzimidazoles (bzs) is widespread in sheep nematodes and increasing in those of cattle. several reasons including the predominant use of pour-on anthelmintics and lack of scales in field conditions lead to under-dosing of cattle and therefore to increased selection pressure. in an field experiment the frequency of bz-resistance associated allele (tac) in codon 200 in the β-tubulin isotype 1 gene of ostertagia ostertagi was monitored over one grazing season (approximately 30 weeks) ...201525725546
prevalence and seasonality of bulk milk antibodies against dictyocaulus viviparus and ostertagia ostertagi in irish pasture-based dairy herds.infections with dictyocaulus viviparus and ostertagia ostertagi nematode parasites are of importance to bovine health and production in temperate areas across the world. losses due to these parasites in dairy herds can be considerable due to decreased milk productivity and fertility. however, information on current epidemiological patterns in irish dairy herds is limited. bulk milk samples were collected from a total of 319 dairy farms across the republic of ireland. the d. viviparus samples wer ...201525709092
gene expression of abc transporters in cooperia oncophora after field and laboratory selection with macrocyclic lactones.the most widespread helminth parasites of grazing cattle in northern europe are the gastrointestinal nematodes ostertagia ostertagi and cooperia oncophora. heavy reliance on the use of macrocyclic lactone (ml) in cattle has led to world-wide emergence of resistance to this drug class in c. oncophora. there is evidence that members of the atp-binding cassette (abc) transporter family, such as p-glycoproteins (p-gp) and multidrug-resistant proteins (mrp), play a role in resistance to ml. in this s ...201425619799
anthelmintic resistance in nematodes of beef cattle in south-west western australia.anthelminthic resistance in nematodes of beef cattle is an emerging issue globally with implications for effective parasite control. the prevalence of resistance in beef cattle in the mediterranean-style climatic zone of south-west western australia was assessed on 19 farms, using faecal egg count reduction tests. pre-treatment faecal worm egg counts were compared with counts at 14 days after treatments with ivermectin (injectable), fenbendazole (oral), or levamisole (oral). a separately grazed ...201525541483
molecular cloning and characterization of a nematode polyprotein antigen/allergen from the human and animal hookworm ancylostoma ceylanicum.nematodes are unable to synthesize fatty acids de novo and must acquire them from the environment or host. it is hypothesized that two unique classes of fatty acid and retinol binding proteins that nematodes produce (fatty acid and retinol binding (far) and nematode polyprotein antigen/allergen (npa)) are used to meet this need. a partial cdna has been cloned corresponding to four subunits of a putative ancylostoma ceylanicum npa (acenpa). the translated amino acid sequence of acenpa shares sequ ...201425481749
activity of ivermectin long-acting injectable (ivomec(®) gold) in first-season grazing cattle exposed to natural challenge conditions in germany.the persistent activity of ivermectin long-acting injection (ivm lai; ivomec® gold, merial; 3.15% ivermectin w/v) against nematode infections of cattle was evaluated under natural challenge conditions. seventy nematode-free brown swiss calves were blocked by pre-treatment bodyweight and allocated randomly to seven groups of 10 animals each: saline (control) at 1 ml/50 kg bodyweight once on day 0 or ivm lai at 1 ml/50 kg bodyweight (630 mcg ivm/kg) on either days 0, 7, 14, 21, 28, or 35. after ho ...201525280515
the parasitic phase of ostertagia ostertagi: quantification of the main life history traits through systematic review and meta-analysis.predictive models of parasite life cycles increase our understanding of how parasite epidemiology is influenced by global changes and can be used to support decisions for more targeted worm control. estimates of parasite population dynamics are needed to parameterize such models. the aim of this study was to quantify the main life history traits of ostertagia ostertagi, economically the most important nematode of cattle in temperate regions. the main parameters determining parasite density durin ...201425229178
annual variation in serum antibody concentrations against gastrointestinal nematodes in beef calves from semi-arid rangelands of western canada.sera from calves originating on a 17,000 ha ranch in southeastern alberta, were collected over three consecutive years (2008-2010) at weaning and analysed for the presence of anti-ostertagia antibodies using the svanovir(®)ostertagia ostertagi-ab elisa kit. faecal samples taken at the same time were analysed for presence of nematode eggs using the modified wisconsin faecal flotation technique. mean optical density ratio (odr) values for all calves were similar in 2008 and 2010 while the 2009 val ...201425086494
parasite control practices on pasture-based dairy farms in the republic of ireland.dictyocaulus viviparus, ostertagia ostertagi (nematode parasites), and fasciola hepatica (trematode parasite) result in productivity losses on dairy farms and impact on animal health through clinical and sub-clinical disease. parasite control in livestock systems is largely based on the use of chemoprophylactic agents (anthelmintics), grazing management, or a combination of both. the objective of this study was to document current parasite control measures employed by irish dairy farmers in a pr ...201424924698
analysis of putative inhibitors of anthelmintic resistance mechanisms in cattle gastrointestinal nematodes.effects of the cytochrome p450 inhibitor piperonyl butoxide and the p-glycoprotein inhibitor verapamil on the efficacy of ivermectin and thiabendazole were studied in vitro in susceptible and resistant isolates of the cattle parasitic nematodes cooperia oncophora and ostertagia ostertagi. the effects of combined use of drug and piperonyl butoxide/verapamil, respectively, were investigated in the egg hatch assay, the larval development assay and the larval migration inhibition assay. the effects ...201424907555
the usefulness of dna derived from third stage larvae in the detection of ashworthius sidemi infection in european bison, by a simple polymerase chain reaction.ashworthius sidemi, a blood-sucking nematode, is a primary parasite of asiatic cervides, primarily sika deer (cervus nippon). as a. sidemi infections are common in bison, red and roe deer, and gastrointestinal nematodes are often exchanged between animals, it is possible that other farm animals such as cows and sheep that may use the same pastures can be infected. hence, histopathological changes observed in the walls of the abomasa and duodena of infected wildlife caused by a strong parasite pr ...201424886355
a stochastic frontier approach to study the relationship between gastrointestinal nematode infections and technical efficiency of dairy farms.the impact of gastrointestinal (gi) nematode infections in dairy farming has traditionally been assessed using partial productivity indicators. but such approaches ignore the impact of infection on the performance of the whole farm. in this study, efficiency analysis was used to study the association of the gi nematode ostertagia ostertagi on the technical efficiency of dairy farms. five years of accountancy data were linked to gi nematode infection data gained from a longitudinal parasitic moni ...201424731629
ostertagia ostertagi macrophage migration inhibitory factor is present in all developmental stages and may cross-regulate host functions through interaction with the host receptor.macrophage migration inhibitory factor (mif) of ostertagia ostertagi, an abomasal parasite of cattle, was characterised in the present study. phylogenetic analysis identified at least three o. ostertagi mifs (oos-mifs), each encoded by a distinct transcript: oos-mif-1.1, oos-mif-1.2 and oos-mif-2. oos-mif-2 is only distantly related to oos-mif-1s, but has higher sequence similarity with the caenorhabditis elegans mif2. oos-mif-1.1 and oos-mif-1.2 are similar (93%) and thus collectively referred ...201424583184
limited efficacy of pour-on anthelmintic treatment of cattle under swedish field conditions.a study on the effect of topical macrocyclic lactones (ml) against gastrointestinal nematodes (gin) in swedish first season grazing cattle (fsg) was performed during the grazing seasons of 2009 and 2010. herds were recruited through farming press and both dairy and beef cattle farms were invited. a questionnaire revealed that 64% of participating farmers dewormed their animals in previous years, and of these 76% used topical formulations with ml. four to six weeks after turnout, 107 (2009) and 6 ...201324533302
a controlled study on gastrointestinal nematodes from two swedish cattle farms showing field evidence of ivermectin resistance.anthelmintic resistance (ar) is an increasing problem for the ruminant livestock sector worldwide. however, the extent of the problem is still relatively unknown, especially for parasitic nematodes of cattle. the effect of ivermectin (ivm) (ivomec inj.®, merial) was investigated in swedish isolates of gastrointestinal nematode (gin) populations showing signs of ar in the field to further characterise the ar status by a range of in vivo and in vitro methods.201424401545
a multiplex pcr-based method to identify strongylid parasite larvae recovered from ovine faecal cultures and/or pasture samples.a multiplex pcr-based method was developed to overcome the limitations of microscopic examination as a means of identifying individual infective larvae from the wide range of strongylid parasite species commonly encountered in sheep in mixed sheep-cattle grazing situations in new zealand. the strategy employed targets unique species-specific sequence markers in the second internal transcribed spacer (its-2) region of ribosomal dna of the nematodes and utilises individual larval lysates as reacti ...201424373513
analysis of the mucosal immune responses induced by single and trickle infections with the bovine abomasal nematode ostertagia ostertagi.the purpose of this study was to provide more information on the kinetics of the immunological changes occurring in the abomasal mucosa after single and trickle infections with the bovine parasite ostertagia ostertagi. the time course analysis of gene expression revealed that the major changes coincided with the emergence of adult worms from the gastric glands. these changes consisted of a simultaneous upregulation of th1- and th2-type cytokines. in addition, a single o. ostertagi infection elic ...201424372091
analysis of cell hyperplasia and parietal cell dysfunction induced by ostertagia ostertagi infection.infections in cattle with the gastric nematode ostertagia ostertagi are associated with decreased acid secretion and profound physio-morphological changes of the gastric mucosa. the purpose of the current study was to investigate the mechanisms triggering these pathophysiological changes. o. ostertagi infection resulted in a marked cellular hyperplasia, which can be explained by increased transcriptional levels of signaling molecules related to the homeostasis of gastric epithelial cells such as ...201324330735
serological evidence of ostertagia ostertagi infection in dairy cows does not impact the efficacy of rabies vaccination during the housing period.nematode infections modulate the immune reaction of humans and livestock and may impair immune responses to non-parasitic antigens such as those present in vaccines. in this study, the relationship between antibodies directed against ostertagia ostertagi, the economically most important nematode infection of cattle in temperate regions, and the magnitude and the kinetics of the antibody response to rabies vaccination was investigated in a commercial dairy herd of 46 cows. during the stabling per ...201324075620
seasonal occurrence of infective nematode larvae in california high sierra pastures grazed by cattle.worm-free holstein calves were used to assess the seasonal variation in numbers of nematode infective larvae on herbage at 2 commercial cow-calf ranches in the sierra nevada mountains. both ranches used herefords as their basic breed. one ranch near sattley, california, is at an elevation of approximately 1,500 m above sea level, whereas the study area on the 2nd ranch near susanville is at an elevation of approximately 1,250 m above sea level. worm-free tracer calves were allowed to graze for a ...198424049905
quality of milk of cows in the first lactation vs. presence of anti-ostertagia antibodies in their milk.invasions of gastrointestinal nematodes in dairy cows may affect animals productivity. the most frequently detected internal parasite of dairy cattle is ostertagia ostertagi. the objective of this study was to determine o. ostertagi invasion extensiveness in selected herds of dairy cattle, with special consideration to cows being in the first lactation, and to analyze the milk yield and contents of basic constituents of milk originating from sero-positive cows. five herds of dairy cattle (403), ...201323971192
gastrointestinal nematodes in grazing dairy cattle from small and medium-sized farms in southern poland.this study aimed to estimate the prevalence of gastrointestinal nematodes and the intensity of infection in grazing dairy cattle from small and medium-sized farms in southern poland. the level of antibodies against ostertagia ostertagi in the bulk tank milk (btm) from the animals was also assessed. rectal fecal samples collected from 361 cows on 20 farms were examined using willis-schlaaf flotation and the mcmaster method. btm samples were tested for the presence of o. ostertagi antibodies using ...201323958284
phylogenetic characterization of β-tubulins and development of pyrosequencing assays for benzimidazole resistance in cattle nematodes.control of helminth infections is a major task in livestock production to prevent health constraints and economic losses. however, resistance to established anthelmintic substances already impedes effective anthelmintic treatment in many regions worldwide. thus, there is an obvious need for sensitive and reliable methods to assess the resistance status of at least the most important nematode populations. several single nucleotide polymorphisms (snps) in the β-tubulin isotype 1 gene of various ne ...201323950913
the association between ostertagia ostertagi antibodies in bulk tank milk samples and parameters linked to cattle reproduction and mortality.in western europe, gastrointestinal nematodes are widespread in dairy cattle. this study was carried out to evaluate the relationship between optical density ratio (odr) measured on bulk tank milk with an indirect ostertagia ostertagi elisa and reproduction/mortality parameters. data were collected between 2008 and 2010 from monitoring carried out on 1643 dairy herds (normandy, western france). odr values of 3 samples from each farm taken from november 2008 to 2010 were averaged and then transfo ...201323806747
presence of ostertagia ostertagi antibodies in bulk tank milk from cattle herds in northern spain.the objective of this survey was to investigate the ostertagia ostertagi infection status of cattle dairy herds from northern spain through measurement of antibody concentration in the bulk tank milk (btm). in addition, management and performance data were collected to determine possible relationships with btm o. ostertagi antibody levels. btm samples were collected in 118 dairy cattle farms from five northern spain autonomic communities in the autumn of 2009 and spring of 2010. the o. ostertagi ...201323806745
real-time pcr detection for quantification of infection levels with ostertagia ostertagi and cooperia oncophora in cattle faeces.a quantitative real-time polymerase chain reaction (qpcr) based on hydrolysis (taqman) probes is described for robust and sensitive detection of the infection levels with eggs and third stage larvae (l3) of cooperia oncophora and ostertagia ostertagi isolated from cattle faeces. the current microscopic method for identification of strongyle nematodes in cattle faeces is labour-intensive where reliable species determination also requires trained expertise, which is increasingly lacking. the goal ...201323764131
predicting the effect of anthelmintic treatment on milk production of dairy cattle in canada using an ostertagia ostertagi elisa from individual milk samples.gastrointestinal nematodes, such as ostertagia ostertagi and several species of cooperia, are ubiquitous in temperate climates and have been shown to have detrimental effects on production in adult dairy cattle. a published meta-analysis demonstrated that overall, producers lose approximately 0.35 kg of milk per parasitized cow per day. enzyme-linked immunosorbent assays (elisas) have the ability to quantify nematode infections in cattle, and thus, could be used to estimate the amount of milk pr ...201323647705
in vitro effects of extracts and purified tannins of sainfoin (onobrychis viciifolia) against two cattle nematodes.sainfoin (onobrychis viciifolia) is a condensed tannin (ct)-containing legume and has anthelmintic potential against gastrointestinal nematodes of ruminants. this study investigated in vitro effects of acetone/water extracts and derived ct fractions from different types of sainfoin (i.e. accessions) against larvae of cooperia oncophora and ostertagia ostertagi by applying the larval feeding inhibition assay (lfia). seven sainfoin accessions were extracted and tested with l1 larvae at 10 and 40 μ ...201323639199
first description of gastrointestinal nematodes of barbary sheep (ammotragus lervia): the case of camelostrongylus mentulatus as a paradigm of phylogenic and specific relationship between the parasite and its ancient host.the gastrointestinal helminth fauna of 24 barbary sheep or aoudad (ammotragus lervia sahariensis) maintained in the parque de rescate de la fauna sahariana (prfs, csic, almeria, spain) was analyzed. most animals (87.5 %) were parasitized, and multiple infections were highly present. the following species were identified: camelostrongylus mentulatus, teladorsagia circumcincta, marshallagia marshalli, ostertagia ostertagi, o. leptospicularis, o. lyrata, haemonchus contortus, teladorsagia trifurcat ...201323616093
weight gain-based targeted selective treatments (tst) of gastrointestinal nematodes in first-season grazing cattle.a three-year trial was performed in south-western sweden to compare animal performance and levels of parasite control in three grazing groups, each with 18-24 first-season grazing (fsg) calves in similar set-stocked pasture enclosures. these groups were subjected to: (1) no parasite control (nt), (2) monthly repeated doramectin (dectomax(®)) injections (sp), or (3) targeted selective weight gain-based anthelmintic treatments (tst) but only when individual calf performance was inferior to the ave ...201323608034
structure of ostertagia ostertagi asp-1: insights into disulfide-mediated cyclization and dimerization.the cysteine-rich secretory/antigen 5/pathogenesis-related 1 (cap) protein superfamily is composed of a functionally diverse group of members that are found in both eukaryotes and prokaryotes. the excretome/secretome of numerous helminths (parasitic nematodes) contains abundant amounts of cap members termed activation-associated secreted proteins (asps). although asps are necessary for the parasitic life cycle in the host, the current lack of structural and functional information limits both und ...201323519657
granule exocytosis of granulysin and granzyme b as a potential key mechanism in vaccine-induced immunity in cattle against the nematode ostertagia ostertagi.ostertagia ostertagi is considered one of the most economically important bovine parasites. as an alternative to anthelmintic treatment, an experimental host-protective vaccine was previously developed on the basis of asp proteins derived from adult worms. intramuscular injection of this vaccine, combined with quila as an adjuvant, significantly reduced fecal egg counts by 59%. however, the immunological mechanisms triggered by the vaccine are still unclear. therefore, in this study, the differe ...201323478322
transcriptome analyses reveal protein and domain families that delineate stage-related development in the economically important parasitic nematodes, ostertagia ostertagi and cooperia oncophora.cooperia oncophora and ostertagia ostertagi are among the most important gastrointestinal nematodes of cattle worldwide. the economic losses caused by these parasites are on the order of hundreds of millions of dollars per year. conventional treatment of these parasites is through anthelmintic drugs; however, as resistance to anthelmintics increases, overall effectiveness has begun decreasing. new methods of control and alternative drug targets are necessary. in-depth analysis of transcriptomic ...201323432754
control trial and fecal egg count reduction test determinations of nematocidal efficacies of moxidectin and generic ivermectin in recently weaned, naturally infected calves.an anthelmintic efficacy study was performed with young, naturally infected beef-type calves obtained at local farms. presumably, the study calves had been recently weaned and had not been treated with a parasiticide prior to study acquisition. after blocking the 24 study calves in accordance with calculated cooperia spp epg counts, the calves were randomly allocated within each block to one of four treatment groups, resulting in 6 animals per treatment group (untreated controls, topical ivermec ...201323380250
nematode burdens of pastured cattle treated once at turnout with eprinomectin extended-release injection.the efficacy of eprinomectin in an extended-release injection (eri) formulation was evaluated against infections with third-stage larvae or eggs of gastrointestinal and pulmonary nematodes in cattle under 120-day natural challenge conditions in a series of five studies conducted in the usa (three studies) and in europe (two studies). for each study, 30 nematode-free (four studies) or 30 cattle harboring naturally acquired nematode infections (one study) were included. the cattle were of various ...201223273928
the efficacy of eprinomectin extended-release injection against naturally acquired nematode parasites of cattle, with special regard to inhibited fourth-stage ostertagia larvae.the efficacy of eprinomectin in an extended-release injection (eri) formulation in the treatment of cattle harboring naturally acquired nematode populations (including inhibited nematodes) was evaluated. five studies were conducted under a similar protocol in the usa, the uk, and in germany. all study animals were infected by grazing naturally contaminated pastures. the adequacy of pasture infectivity was confirmed by examining tracer calves prior to allocation and treatment of the study animals ...201223273781
an eprinomectin extended-release injection formulation providing nematode control in cattle for up to 150 days.a series of 10 dose confirmation studies was conducted to evaluate the persistent activity of an extended-release injectable (eri) formulation of eprinomectin against single point challenge infections of gastrointestinal and pulmonary nematodes of cattle. the formulation, selected based on the optimal combination of high nematode efficacy, appropriate plasma profile, and satisfactory tissue residue levels, includes 5% poly(d,l-lactide-co-glycolic)acid (plga) and is designed to deliver eprinomect ...201223273777
do the changes in the behaviours of cattle during parasitism with ostertagia ostertagi have a potential diagnostic value?we investigated the magnitude of temporal changes in activity, posture and feeding behaviour of cattle infected with ostertagia ostertagi, and their reversal after treatment with an anthelmintic. twenty-six, 3-month-old, holstein-friesian bulls were allocated to one of three treatment groups. bulls in two of those (groups p and pa) received 100,000 larvae on three occasions (days 0, 7 and 14) and the remaining animals served as controls (c). the pa group also received an anthelmintic on day 31. ...201323218221
resistance against gastrointestinal nematodes in crioulo lageano and crossbred angus cattle in southern brazil.gastrointestinal nematode (gin) infection is a major cause of production losses in cattle. this study was carried out to evaluate the natural resistance against nematode infection in crioulo lageano and crossbred angus male calves. crioulo lageano is a local cattle breed in the state of santa catarina, in southern brazil. ten weaned calves of each breed were grazed together on pasture and naturally infected with nematodes between july 2009 and december 2010. once every 28 days, we collected feca ...201323177359
dexamethasone treatment interferes with the pharmacokinetics of ivermectin in young cattle.an experiment was carried out to study the possible interaction between dexamethasone (dxm) treatment and the efficacy of ivermectin (ivm) treatment in young cattle. two groups, each of seven calves, were experimentally inoculated with an equal mixture containing 15,000 third stage larvae of cooperia oncophora and ostertagia ostertagi each, and with no history of being resistant to any anthelmintics. however, in this study c. oncophora was unexpectedly classified as ivm-resistant according to th ...201222959189
characterisation of macrocyclic lactone resistance in two field-derived isolates of cooperia oncophora.the anthelmintic sensitivity of two field-derived isolates (designated fi001 and fi004) of cattle nematodes from beef farms in scotland were investigated in a controlled efficacy test (cet). efficacies of ivermectin pour-on (ivm-po), ivm injectable (ivm-inj) and moxidectin pour-on (mox-po) formulations were assessed. in each group, five helminth-naïve calves were infected experimentally with 50,000 third stage larvae from either isolate and administered with anthelmintic at the manufacturers' re ...201222884912
helminths of roe deer (capreolus capreolus) in the middle black sea region of turkey.fifteen roe deer were examined at necropsy from northern turkey in the period 2006-2010 for the helminth infections. totally 6470 helminth specimens were collected and identified by morphological criteria. twenty-five helminth species were identified (1 of the class trematoda, 1 of cestoda and 23 of nematoda). dicrocoelium dendriticum (prevalence 20%) was found in liver. cysticercus tenuicollis (6.6%) was found in mesentery. haemonchus contortus (53.3%), ostertagia leptospicularis (73.3%), o. le ...201222766455
the effects of acute versus chronic health challenges on the behavior of beef cattle.the changes in behavior associated with a (subclinical) acute and a chronic health challenge were investigated to assess their potential value for the development of an early disease detection system in beef cattle. the hypothesis was that acute challenges would lead to acute but transient changes in behavior, whereas the converse would be the case during chronic challenges, with changes taking longer to develop, but being more persistent. for this purpose, holstein-friesian beef bulls were chal ...201222745185
effects of gastrointestinal parasites on parasite burden, rectal temperature, and antibody titer responses to vaccination and infectious bovine rhinotracheitis virus challenge.thirty-three colostrum-deprived holstein bull calves (initial bw of 131 ± 4 kg) were used to determine the effect of timing of anthelmintic administration relative to vaccination on antibody titer response to vaccine component antigens. when calves were at least 3 mo of age, they were sorted randomly into individual pens and assigned to 1 of 3 treatment groups, treatments consisted of 1) dewormed 2 wk before vaccination (dpv), 2) dewormed at the time of vaccination (dv), or 3) control, vaccinate ...201222648753
assessing resistance against macrocyclic lactones in gastro-intestinal nematodes in cattle using the faecal egg count reduction test and the controlled efficacy test.the main objective of the present study was to evaluate the accuracy of the faecal egg count reduction test (fecrt) to assess the resistance status of ivermectin (ivm)-resistant isolates of the cattle nematodes ostertagia ostertagi and cooperia oncophora, using the controlled efficacy test (worm counts) as a reference. the second objective was to investigate whether both ivm-resistant isolates showed side-resistance against moxidectin (mox) under controlled conditions. thirty male holstein calve ...201222647465
reevaluation of efficacy against nematode parasites and pharmacokinetics of topical eprinomectin in cattle.a study was conducted to confirm the efficacy of topical eprinomectin against nematodes and to evaluate the pharmacokinetics in cattle prevented from having physical contact with other cattle and from self-grooming. sixteen male brown swiss calves were infected with larvae of recently isolated nematode parasites. inoculation was scheduled so that the nematodes were expected to be adults at the time of treatment. animals were blocked based on pretreatment body weight and randomly allocated to the ...201222638921
exposure to pasture borne nematodes affects individual milk yield in swedish dairy herds.the association between exposure to gastrointestinal nematode (gin) parasitism, indicated by elevated individual optical density ratio (odr) to ostertagia ostertagi, and individual milk production was analysed in dairy cows. the multivariable analysis also accounted for other sources of variation than exposure to gin parasitism. intra- and inter-herd variation in parasite exposure was also evaluated. organic and conventional herds located in south-east sweden (13 herds per system) were visited d ...201222459108
[taxonomic revision of the genus orloffia (nematoda: ostertagiinae) based on an its-2 rdna study].a comparative study of its-2 rdna of the nematodes of the genera orloffia, ostertagia, teladorsagia, and trichostrongylus was performed. the obtained results allow us to consider orloffia, ostertagia, and teladorsagia as closely related but distinct genera. the results of the study indicate that o. bisonis is the only valid species in the genus orloffia, which has two morphologically distinct forms of males: o. bisonis (major morph) and o. kasakhstanica (minor morph). the percentage of similarit ...201122292291
parasites of chamois in new zealand.abstract sir, - andrews'((2)) checklist of helminth parasites of wild ruminants in new zealand recorded the presence of 10 species of gastrointestinal nematodes in chamois (rupicapra rupicapra rupicapra l.) from "central south island". in october 1978 we examined 28 freshly-shot chamois cadavers from the harper-avoca watershed in the headwaters of the rakaia river. six of the nematode species reported by andrews were found again; viz. ostertagia ostertagi, o. circumcincta, o. trifurcata, nemat ...198122133071
the activity of albendazole against adult and larval gastrointestinal nematodes in naturally infected calves in the netherlands.summary the activity of albendazole against gastrointestinal helminths in naturally infected calves in the netherlands was tested. the calves were in their fist grazing season and kept in two groups of ten. one of these groups was grazed alternately with sheep. five out of each group were drenched with albendazole (7.5 mg/kg) on the day they were housed (november 1). before and 2, 14, and 28 days after treatment individual faecal samples were taken from all calves and larval cultures were mad ...197922039826
optimization of in-house elisa based on recombinant major sperm protein (rmsp) of dictyocaulus viviparus for the detection of lungworm infection in cattle.the aim of this study was to optimize an in-house elisa based on a recombinant version of the major sperm protein (msp) of dictyocaulus viviparus for routine diagnosis of lungworm infection in cattle. a recombinant msp (rmsp) was cloned into pgex-6p-1 vector and expressed as a glutathione-s-transferase (gst) fusion protein in escherichia coli bl21 (de3) chemically competent cells. the product was then employed as capture antigen in an elisa, and validated against 304 samples of known status (216 ...201122019470
Effects of farm management practices and environmental factors on bulk tank milk antibodies against gastrointestinal nematodes in dairy farms across Canada.Enzyme-linked immunosorbent assays (ELISAs) have been used as a diagnostic tool to quantify levels of gastrointestinal nematodes in dairy cattle by measuring Ostertagia ostertagi antibodies in milk. Higher levels of O. ostertagi antibodies measured by ELISA methods, referred to as optical density ratios (ODRs), are associated with decreased milk production in dairy cattle. On-farm management practices (e.g. pasturing techniques and anthelmintic usage) can influence the exposure of cattle to nema ...201122018549
galectin-11 induction in the gastrointestinal tract of cattle following nematode and protozoan infections.galectin-11 (lgals11) has been suggested to play an important role in protective immunity against gastrointestinal nematodes in ruminants. however, in cattle, this molecule has not been characterized in detail. in the current study, it was shown that transcription of lgals11 was highly inducible in the bovine abomasal mucosa after an ostertagia ostertagi infection. lgals11 protein expression was also increased in the abomasal mucosa following o. ostertagi infection and localized to the nucleus a ...201121958368
Metagenome plasticity of the bovine abomasal microbiota in immune animals in response to Ostertagia ostertagi infection.Infections in cattle by the abomasal nematode Ostertagia ostertagi result in impaired gastrointestinal function. Six partially immune animals were developed using multiple drug-attenuated infections, and these animals displayed reduced worm burdens and a slightly elevated abomasal pH upon reinfection. In this study, we characterized the abomasal microbiota in response to reinfection using metagenomic tools. Compared to uninfected controls, infection did not induce a significant change in the mic ...201121931709
Use of diagnostic markers to monitor fasciolosis and gastrointestinal nematodes on an organic dairy farm.A 12-month study was conducted to assess and monitor gastrointestinal tract nematodes and liver fluke in cohorts of cattle on a Scottish organic dairy farm. Various diagnostic markers for helminth parasites of cattle from different age groups were assessed monthly from April 2007 to March 2008. First season grazing stock were subjected to significant challenge from Ostertagia ostertagi nematodes as reflected in serum pepsinogen concentrations, which rose markedly in the second half of the grazin ...201121908552
attempts to immunise sheep against teladorsagia circumcincta using fourth stage larval extracts.a concanavilina (cona) binding fraction of a detergent soluble membrane extract from teladorsagia circumcincta (formerly ostertagia circumcincta) fourth stage larvae was isolated and two vaccine trials were conducted with this preparation in groups of 7 worm free sheep. all groups were challenged with a total of 5000 t. circumcincta larvae from one week after the final immunisation and protection assessed by comparing the egg and worm counts, and length of developing worms, of the immunised grou ...201121793859
comparative efficacy of trichlorphon and trichlorphon/ivermectin combination treatment against anthelmintic-resistant cattle nematodes in argentina.twenty-four holando argentino male calves were treated orally with 50 mg/kg body weight trichlorphon (tcf); 0.2 mg/kg body weight subcutaneous ivermectin (ivm); a combination of tcf+ivm at the same doses and administration routes; or remained untreated (control group). all calves were necropsied at day 14 post treatment for counting and identification of worms from abomasum, small and large intestines and lungs to determine the absolute efficacy (controlled efficacy test) for each treatment. usi ...201121739380
condensed tannins act against cattle nematodes.the use of natural plant anthelmintics was suggested as a possible alternative control of gastrointestinal nematodes (gin) in ruminants. direct anthelmintic effects of tannin-containing plants have already been shown in sheep and goat gin. these anthelmintic properties are mainly associated with condensed tannins. in the present study, we evaluated possible in vitro effects of three tannin-containing plants against bovine gin. effects of onobrychis viciifolia, lotus pedunculatus and lotus cornic ...201121726942
immunologically based control strategies for ostertagiosis in cattle: where do we stand ?ostertagia ostertagi is one of the most important gastrointestinal parasites infecting millions of cattle in temperate climate areas. since infection leads to significant losses in productivity, farmers are pushed, due to the on-going intensification of the livestock production systems, to frequently administer anthelmintics in order to minimize the exposure of their animals to this parasite. however, whether such approach is sustainable in the long term, especially in an era of emerging drug re ...201121722144
altered avr-14b gene transcription patterns in ivermectin-resistant isolates of the cattle parasites, cooperia oncophora and ostertagia ostertagi.ivermectin (ivm) resistance is an emerging problem for the control of gastrointestinal nematodes of cattle such as cooperia oncophora and ostertagia ostertagi. although there is still a poor understanding of the molecular basis of macrocyclic lactone (ml)-resistance, it is clear that ivm exerts its activity by binding to glutamate-gated chloride (glucl) channels within the parasite's neuromuscular system. one of the glucl genes (avr-14) encodes, via alternative splicing, two subunits, avr-14a an ...201121683704
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