abundance and survival of infective larvae of the cattle nematodes cooperia punctata, haemonchus placei and oesophagostomum radiatum from faecal pats in a wet tropical climate.observations were made on the abundance and survival of haemonchus placei, cooperia punctata and oesophagostomum radiatum infective larvae from cattle faecal pats exposed at various times of the year in north queensland wet tropics. pats exposed in the hot, wet season yielded abundant larvae on herbage. in the dry season, although low numbers of infective larvae were usual, considerable numbers were produced under conditions of heavy dews on dense herbage. irrespective of season of deposition of ...19883190586
in vitro activity of brazilian strains of the predatory fungi arthrobotrys spp. on free-living nematodes and infective larvae of haemonchus vitro tests were carried out to assess the activity of 26 brazilian isolates of predatory fungi of the genus arthrobotrys on a free-living nematode (panagrellus sp.) and on infective larvae of haemonchus placei, a parasitic gastrointestinal nematode of cattle. the results showed that the free-living nematode panagrellus sp. was the most preyed upon, compared to h. placei, for all the fungal treatments. also, variable predatory capacity was observed for different fungal isolates belonging to t ...200011080778
persistent efficacy of topical eprinomectin against nematode parasites in cattle.six studies were conducted to evaluate the persistent efficacy of eprinomectin pour-on against experimental challenges with infective nematode larvae in calves. in each study, calves were randomly assigned to one untreated group and up to four test groups, which were treated with eprinomectin at 500 microg/kg body weight at weekly intervals before single bolus challenge. the calves were necropsied approximately 4 weeks after challenge infection for nematode recovery. eprinomectin pour-on provide ...200011097305
ostertagia, haemonchus, cooperia, and oesophagostomum: construction and characterization of genus-specific dna probes to differentiate important parasites of cattle.partial genomic dna libraries for four common cattle parasites, ostertagia ostertagi (oo), haemonchus placei (hp), cooperia oncophora (co), and oesophagostomum radiatum (or), were generated and differentially screened with radiolabeled homologous and heterologous genomic dna. clones were identified from each parasite species which did not cross react with dna from the heterologous genera by southern blot or slot-blot analyses. four clones, poo2, php2.1, pco2, and por14 were chosen for further ex ...19948299764
inhibited development of trichostrongylid worms in grazing cattle.inhibition of development of gastro-intestinal trichostrongylid worms was studied using successive groups of tracer calves and groups of continuously grazed calves over one year in the tully area of north queensland lowland wet tropics. the results, assessed by means of worms from these calves recovered at necropsy 3 weeks after their removal from pastures, showed inhibition in the development of haemonchus placei and cooperia punctata at the early fourth stage at the approach to and during the ...19892590137
anthelmintic efficacy of febantel paste in naturally infected calves.the purpose of the present study was to verify results of the lowest dose (5 mg kg-1) of febantel evaluated in an earlier trial in which there were no differences in efficacies of three dose rates (5, 7.5 and 10 mg kg-1 body weight) against natural gastrointestinal nematode infections of cattle. fourteen angus calves (mean weight and age of 155 kg and 525 days, respectively), from the same farm, with relatively heavy (mean of 448 eggs g-1 feces (epg] parasite burdens were selected. after an adju ...19902353426
the relationships among ecto- and endoparasite levels, class i antigens of the bovine major histocompatibility system, immunoglobulin e levels and weight gain.natural infestations of the cattle tick boophilus microplus, levels of the buffalo fly haematobia irritants exigua and faecal nematode egg concentrations (bunostomum phlebotomum, cooperia spp., haemonchus placei, oesophagostomum radiatum and trichostrongylus axei) were assessed in 221 belmont red calves during the post-weaning period, when the animals were between 9 and 18 months of age. in addition, the 98 males of this group were challenged with b. microplus larvae on two separate occasions. t ...19902316176
efficacy of abamectin against natural infections of gastrointestinal nematodes and lungworm of cattle with special emphasis on inhibited, early fourth stage larvae of ostertagia ostertagi.the anthelmintic efficacy of abamectin (avermectin b1) was evaluated against gastrointestinal nematodes, including ostertagia ostertagi inhibited larvae and lungworm, in yearling crossbred beef heifers during late spring. the calves were grazed on contaminated pasture for 10 weeks and then held under conditions free of nematode infection for 3 weeks prior to allotment and treatment on 5 june. thirteen calves were randomly assigned to two groups of six by restricted randomization on body weights; ...19921532875
the role of the larval stages of haemonchus placei infections of cattle in immunity. 196314053281
a preliminary study of the effect of microclimate on third-stage larvae of haemonchus contortus and haemonchus placei on irrigated pasture.assessments were made on the influence of several microclimatic variables on the availability of third-stage larvae of haemonchus contortus and haemonchus placei on four strata of irrigated kikuyu pasture. three replicates of these pasture samples were collected on 18 sample days over 12 months and the log10 mean counts of the larvae recovered were analysed by a step-wise regression model. predictors for the log counts of the four strata for the two nematode species included relative humidity, i ...19921428508
host specificity of haemonchus spp. for domestic ruminants in the savanna in northern ivory coast.three haemonchus species (haemonchus contortus, haemonchus placei and haemonchus similis) live in sympatry in the savanna of north côte d'ivoire. four domestic ruminant hosts (zebu-cattle, taurine-cattle, sheep and goats) share the same pastures throughout the year. our post-mortem data imply that a haemonchus spp. circulation exists among the different hosts species in the savanna of north côte d'ivoire. under field conditions, mixed congeneric infections were the rule except in sheep where mon ...200314519319
persistent activity of doramectin injectable formulation against experimental challenge with haemonchus placei in cattle.two studies were conducted in north america to evaluate the persistent activity of doramectin injectable formulation against experimental challenge with haemonchus placei. in both studies, calves were randomly assigned to 1 of 4 treatment groups (n = 10 per group) or a larval viability group (n = 2). calves were treated subcutaneously in the lateral midline of the neck with saline (1 ml/50 kg) on day 0, or with doramectin (200 mg/kg = 1 ml/50 kg) on day 0, 7, or 14. animals used to assess larval ...199910489196
seasonal pattern of inhibition of ostertagia ostertagi in calves in northeast mississippi.the composition of, and seasonal changes in, populations of gastrointestinal parasites of calves in northeast mississippi were determined for 10 months post-weaning. after weaning on 15 october, 20 mixed breed beef steers were grazed together on a 4 ha fescue/bermudagrass pasture. from november through august of the following year, two of the calves were removed each month for necropsy and counting of gastrointestinal nematodes. eight species of worms were found: haemonchus placei, ostertagia os ...19968983154
differential recoveries from faecal cultures of larvae of some gastro-intestinal nematodes of cattle.faecal cultures were established using bovine faeces containing known numbers of eggs from either oesophagostomum radiatum, haemonchus placei, cooperia pectinata or a mixture of all three. a substantially greater percentage of larvae was recovered from cultures of o. radiatum and c. pectinata than was recovered from cultures of h. placei. the same pattern was observed in mixed cultures although yields of larvae from all species in mixed cultures were significantly reduced (p less than 0.001). th ...19883397511
parasites of domestic and wild animals in south africa. xlv. helminths of dairy calves on dry-land kikuyu grass pastures in the eastern cape province.successive pairs of approximately 4-month-old friesland bull calves, raised under worm-free conditions, were exposed to helminth infection for 14 days on dry-land kikuyu grass pastures at 28-day to monthly intervals, on a coastal farm in a non-seasonal rainfall region of the eastern cape province. with the exception of one pair of calves exposed for 28 days, this procedure was repeated for 28 consecutive months from december 1982 to march 1985. the day after removal from the pastures one calf of ...200415732456
persistent anthelmintic activity of abamectin injection in cattle.the duration of the anthelmintic activity of abamectin administered by subcutaneous injection at 200 microg/kg was determined using induced infections of haemonchus placei, ostertagia ostertagi, cooperia spp., and oesophagostomum radiatum in cattle. twenty-four friesian calves, raised under worm-free conditions, were assigned to four groups of six animals using a randomised block design based on bodyweight. one group acted as untreated controls and the other three were treated with abamectin 14, ...199216031652
antagonistic effect of predacious arthrobotrys fungi on infective haemonchus placei larvae.laboratory experiments were performed to investigate the ability of isolates from the predacious fungus species arthrobotrys conoides (one isolate) and al. robusta (four isolates) to trap and kill infective haemonchus placei larvae. three groups for each isolate were formed: group 1, fungi and infective larvae; group 2, fungi; group 3, infective larvae. there were statistically significant differences (p < 0.05) between the antagonistic effects of three isolates of a. robusta, but there was no s ...19938354858
effects of time of day, season and stratum on haemonchus contortus and haemonchus placei third-stage larvae on irrigated pasture.the effect of time of day, season and stratum of herbage and soil on the availability of haemonchus contortus and haemonchus placei third-stage larvae (l3) on pasture was assessed. feces from infected calves and lambs were placed on pasture plots and samples of upper herbage, lower herbage, mat and soil were collected at five intervals per day throughout the daylight hours on 18 sample days over 12 months. using recovery rate factors derived from a preliminary investigation on the efficacy of la ...19911763493
ostertagia ostertagi challenge of calves vaccinated with haemonchus placei intestinal homogenate.the protective capacity of vaccination with haemonchus placei whole gut homogenate against challenge with the non-blood-feeding nematode ostertagia ostertagi was evaluated in calves. ten helminth-free calves were randomly assigned to two groups. group 1 received 100microg h. placei intestinal homogenate in the adjuvant 5% dextran sulfate/pbs, while group 2 received the adjuvant alone. injections were administered subcutaneously on days 0 and 28. all calves were challenged with approximately 26,1 ...200010828516
efficacy of an albendazole feed formulation against bovine gastrointestinal nematodes including arrested larvae of ostertagia ostertagi.the efficacy of an albendazole feed premix formulation was compared with that of an albendazole drench suspension for control of gastrointestinal nematodes in 31 beef cattle. the premix (11 cattle) and drench suspension (9 cattle) were found to have similar efficacies at a dosage of 7.5 mg/kg of body weight. when compared with controls (11 cattle), both formulations caused significant (p less than 0.05) reductions in worm counts with an efficacy of 98% or greater against adult haemonchus placei, ...19863946888
endectocide activity of a new long-action formulation containing 2.25% ivermectin+1.25% abamectin in cattle.the present work aimed to evaluate the endectocide activity of a new injectable long-action formulation, containing ivermectin (ivm) and abamectin (aba). in each one of the four experiments performed, the following groups were formed: group i: 2.25% ivm (450 microg/kg)+1.25% aba (250 microg/kg), group ii: 3.15% ivm (630 microg/kg) and group iii: control. eighteen bovine naturally infected by gastrointestinal nematoda were selected for anthelmintic evaluation and necropsied on posttreatment day ( ...200818562119
the epidemiology of gastrointestinal nematodes of dairy cattle in central kenya.the epidemiology of h. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in kiambu district, central kenya during each of 13 one-month periods from april 1993 to april 1994. on each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. twelve of the animals were designated for bimonthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood an ...200111360797
a multiplex pcr assay for differentiating economically important gastrointestinal nematodes of cattle.a multiplex polymerase chain reaction (pcr) test was developed for identifying gastrointestinal (gi) nematodes that commonly infect cattle. this assay was developed using adult-derived genomic dna and shown capable of discriminating parasite eggs from the feces of experimentally-infected animals at both the species and genus levels. sequence data from internal (its) and external (ets) transcribed spacers of the ribosomal dna (rdna) repeats as well as the 3'-end of the small subunit rdna and 5'-e ...200111390072
further characterization of a cattle nematode population with demonstrated resistance to current anthelmintics.we previously documented the appearance of cattle nematode parasites resistant to avermectins, milbemycin, and a benzimidazole at the end of a grazing season in a backgrounding operation in the upper midwestern us. to further characterize the pattern of drug resistance, we extended the study to (1) monitor the animals over the course of the grazing season; (2) increase the number of animals slaughtered at the end of the season to minimize the effect of potential outlying observations; (3) increa ...200919897305
haemonchus placei in calves: effects of dietary protein and multiple experimental infection on worm establishment and experiment was conducted to examine the influence of dietary protein and immunisation on parasite establishment and pathogenesis of haemonchus placei in calves. four groups of 4-6-month-old worm-free calves (n = 4) were given a low protein diet (lp) containing 213 g crude protein (cp) per head per day or a high-protein diet (hp) containing 469 g per head per day cp. five weeks later, calves in one of the two groups of each dietary treatment were given 50,000 h. placei infective larvae (l3). t ...19957483235
activity of doramectin against nematode endoparasites of cattle.a series of 28 controlled anthelmintic studies, involving 634 cattle, was conducted throughout north america and europe to evaluate the efficacy of doramectin against a broad range of gastrointestinal parasitic nematode species and lungworms in naturally and experimentally infected animals. within each study, one or two groups were treated with doramectin at 200 micrograms kg-1 and another group received no drug treatment. worm burdens were estimated by standardised techniques, and efficacy asse ...19938236735
efficacy of doramectin against field nematode infections of cattle in latin america.two studies were conducted, one in argentina and one in brazil, to evaluate the therapeutic efficacy of doramectin administered subcutaneously at a dose rate of 200 micrograms kg-1 (1 ml per 50 kg) to cattle harboring mixed field infections of gastrointestinal nematodes. in each trial, 20 heifers were randomly allocated to a control or treated group of ten animals each, on the basis of fecal egg counts. animals in the treated and control groups received an injection of doramectin or saline in th ...19938236736
multispecies and multiple anthelmintic resistance on cattle nematodes in a farm in argentina: the beginning of high resistance?there are very few resistance records on cattle nematodes. south american successive records have been increasing rapidly since the year 2000. in argentina, increasing dissatisfaction based on the exclusive use of macrocyclic lactones has prompted the use of benzimidazoles in the pampean region. the studied farm is located in the argentina humid pampas and had apparently poor results after anthelmintic treatments. evaluation of resistance was firstly based on faecal egg reduction after treatment ...200312911862
seasonal prevalence of gastrointestinal nematode parasites of sheep in northern region of nile delta, egypt.over 1 year, from january to december 1999, a total of 173 slaughtered sheep at al-mahala abattoir were examined for presence of nematode parasites. eighteen sheep (10.4%) were infected with eight different species of nematodes. the prevalence rates of detected nematode parasites were; haemonchus contortus (3.5%), haemonchus placei (1.7%), trichuris ovis (5.8%), parabronema skrjabini (2.9%), ostertagia trifurcata (1.2%), chabertia ovina (0.6%) and strongyloides papillosus (0.6%), and graphidiops ...201020922430
host movement and the genetic structure of populations of parasitic nematodes.mitochondrial dna (mtdna) sequence data were used to compare the population genetic structures of five species of parasitic nematodes from three different hosts: ostertagia ostertagi and haemonchus placei from cattle, h. contortus and teladorsagia circumcincta from sheep, and mazamastrongylus odocoilei from white-tailed deer. the parasites of sheep and cattle showed a pattern consistent with high gene flow among populations. the parasite of deer showed a pattern of substantial population subdivi ...19958582607
characterization and localization of saposin-like protein-2 (sap-2) in fasciola gigantica.fasciola gigantica saposin-like protein-2 (fgsap-2) belongs to a family of lipid-interacting proteins that are involved in the cytolysis of target cells. in this study, we have cloned and expressed fgsap-2 and produced the antibody against this recombinant protein. rabbit antiserum against rfgsap-2 reacted with a similar native protein in the whole body extracts of the 4-week-old juvenile and adult stage, as well as a protein in their excretion-secretion, but not in the tegument. in situ hybridi ...201021188603
development of graphidium strigosum (nematoda, haemonchidae) in its natural host, the rabbit (oryctolagus cuniculus) and comparison with several haemonchidae parasites of ruminants.the morphogenesis (studied for the first time) and the chronology of the life cycle of graphidium strigosum (dujardin, 1845) were studied in detail in its natural host, oryctolagus cuniculus. naive rabbits were each infected per os with g. strigosum infective larvae (l3). animals were euthanized each day for the first 10 days after infection (dai), then every 2 days from 12 to 40 dai. the free living period lasted 5-8 days at 24°c. by 1 dai, all the larvae were exsheathed in the stomach. the thi ...201121210152
eprinomectin: a novel avermectin for use as a topical endectocide for cattle.eprinomectin (mk-397 or 4"-epi-acetylamino-4"-deoxy-avermectin b1) is a novel avermectin selected for development as a topical endectocide for all cattle, including lactating dairy cows. herein, we show its anthelmintic, insecticidal and miticidal activity. to determine its anthelmintic capabilities, eprinomectin was tested topically on jersey calves at 0.08, 0.2, or 0.5 mg kg-1 in a probe formulation against experimental infections of adult haemonchus placei, ostertagia ostertagi, trichostrongy ...19969024867
effect of simulated rain, coat length and exposure to natural climatic conditions on the efficacy of a topical formulation of eprinomectin against endoparasites of cattle.a series of five controlled studies involving 114 cattle were conducted in australia, north america and the united kingdom to examine the effect of simulated rain, coat length and exposure to natural climatic conditions, on the efficacy of a topical formulation of eprinomectin against nematode parasites of cattle. in all trials infections were induced with a range of bovine nematode species and treatment was applied when the majority of nematodes were mature. in one study, simulated rain was app ...19979187034
species diversity and acquisition of gastrointestinal parasites in calves aged 0-13 months in periurban livestock production in inspections on 51 calves were conducted to investigate acquisition and spectrum of gastrointestinal parasites in young calves in periurban livestock production in mali. generalized linear models with herd as a repeated effect were used to test the influence of management, age and season of birth on parasite numbers and diversity. parasite number and burden increased with age. in the age class 4-13 months animals carried already up to eight different gastrointestinal parasite species. ...200716934937
haemonchus placei and haemonchus contortus are distinct species based on mtdna evidence.debates continue over the extent to which the parasitic trichostrongylids haemonchus placei and haemonchus contortus hybridise in nature, and whether they deserve species status. mitochondrial nd4 gene sequences from individuals of each putative species collected from populations around the united states indicate that the two species are highly differentiated at the mtdna level. furthermore, there was no evidence of introgressive hybridisation occurring in wild populations.19979421728
reduced efficacy of macrocyclic lactone treatments in controlling gastrointestinal nematode infections of weaner dairy calves in subtropical eastern australia.faecal egg count reduction tests (fecrts) for macrocyclic lactone (ml) and levamisole (lev) drenches were conducted on two dairy farms in the subtropical, summer rainfall region of eastern australia to determine if anthelmintic failure contributed to severe gastrointestinal nematode infections observed in weaner calves. subtropical cooperia spp. were the dominant nematodes on both farms although significant numbers of haemonchus placei were also present on farm 2. on farm 1, moxidectin pour-on ( ...201019932565
efficacy of moxidectin pour-on against gastrointestinal nematodes and dictyocaulus viviparus in cattle.twenty crossbred beef heifer calves were used for an efficacy evaluation of 0.5% moxidectin pour-on against gastrointestinal nematodes and dictyocaulus viviparus. the latter parasite and bunostomum phlebotomum were the target species. the calves were exposed to natural infection on pasture from late september to december 22. additionally, all calves were experimentally infected with b. phlebotomum at 71 and 29 days before treatment and with d. viviparus at 29 days before treatment. the 20 calves ...19968893482
vaccination of calves with haemonchus placei intestinal homogenate.the ability of adult haemonchus placei intestinal homogenate to confer protection against homologous challenge infection was evaluated. calves were immunized twice with 100 microg h. placei intestinal protein in 5% dextran-sulfate/pbs (vaccinates) or pbs alone (controls) and were challenged with approximately 3300 infective h. placei larvae. there was no significant difference between groups in the total number of nematodes recovered but significantly fewer (p < 0.001) adult females were recover ...200010714462
epidemiology of gastrointestinal nematodes in cattle on traditional, small-scale dairy and large-scale dairy farms in iringa district, tanzania.a longitudinal study was carried out to determine the prevalence, distribution and intensity of gastrointestinal (gi) nematodes in traditional, small-scale dairy and large-scale dairy cattle farms in iringa district, southern highlands of tanzania. coprological examination of cohorts for gi nematode eggs in faeces, tracer worm counts and pasture larval counts were performed monthly for 1 year. results indicated that the type of management, especially the grazing habit has a significant influence ...200415710529
fasciola gigantica: production and characterization of a monoclonal antibody against recombinant cathepsin b3.a number of monoclonal antibodies (moabs) against a recombinant cathepsin b3 (rcatb3) of fasciola gigantica were produced in balb/c mice. reactivity and specificity of these moabs were assessed by indirect elisa and immunoblotting techniques. six stable clones, namely 1c4, 1e9, 2e5, 2f9, 5b4, 5d7 were obtained. all moabs reacted with rcatb3 at molecular weight (mw) 37 kda as well as the glycosylated peptide at 55-75 kda and with the native catb3 at mw 37 kda in wb extracts of metacercariae (met) ...201120736007
endectocide activity of a pour-on formulation containing 1.5 per cent ivermectin +0.5 per cent abamectin in cattle.the present work aimed to evaluate, through ten different studies, the therapeutic efficacy of a new pour-on formulation, containing 1.5 per cent ivermectin +0.5 per cent abamectin, against parasites of cattle. results obtained on trials against rhipicephalus (boophilus) microplus showed that the pour-on combination of 1.5 per cent ivermectin +0.5 per cent abamectin obtained superior efficacy indexes against this ectoparasite, when compared with formulations containing 0.5 per cent ivermectin, 1 ...201526392893
production and characterization of a monoclonal antibody specific to 16 kda antigen of paramphistomum gracile.a number of monoclonal antibodies (moabs) against the 16 kda antigen of paramphistomum gracile (16 kdaagpg) were produced in vitro by hybridoma technique. reactivity and specificity of these moabs were evaluated by elisa and immunoblotting assays. seven moab clones were selected from the stable hybridoma clones, namely 1d10, 2d7, 3b10, 3d9, 4f1, 4g4, and 5g12. it was found to be igm and kappa light chain isotypes. by immunoblotting and elisa, all moabs reacted with purified 16 kdaagpg at molecul ...201727770198
production and characterization of a monoclonal antibody against recombinant cathepsin l1 of fasciola gigantica.monoclonal antibodies (moabs) against a recombinant cathepsin l1 of fasciola gigantica (rfgcatl1) were produced in vitro by fusion of balb/c mice spleen cells immunized with rfgcatl1 and mouse myeloma cells. reactivity and specificity of these moabs were evaluated by indirect elisa and immunoblotting techniques. seven moab clones were selected from the stable hybridoma clones, namely 1e10, 1f5, 3d11, 4b10, 4d3, 4e3 and 5e7. clones 1e10, 1f5 and 3d11 were igm, whereas clones 4b10, 4d3, 4e3 and 5e ...201424736227
protection against high-dose homologous infection in calves immunized with intestine or membrane extracts from haemonchus placei.control of haemonchus placei, one of the most important cattle nematodes in brazil, relies on the use of anthelmintics. however, there is a need for integrated control, which includes active immunization. the aim of this work was to assess the protection afforded to calves by immunization with adult h. placei extracts against a high-dose challenge infection, a condition frequently found in the tropics. holstein calves aged 8-10 months were immunized four times with intestinal extracts (group d) ...200818065148
the identification of cattle nematode parasites resistant to multiple classes of anthelmintics in a commercial cattle population in the us.resistance to modern anthelmintics by ruminant nematode parasites is an increasing problem throughout the world. to date the problem has largely been reported in parasites of small ruminants, but there are increasing reports of such resistance in nematodes recovered from cattle. until now there have been no published reports of drug resistant parasites from cattle in north america. in 2002 a producer in the upper midwest who backgrounds young cattle acquired from the southeastern us experienced ...200919900760
titration of subcutaneously administered eprinomectin against mature and immature nematodes in cattle.eprinomectin has been approved for use as a topically applied endectocide for beef and dairy cattle. to determine if eprinomectin has utility as an injectable anthelmintic, it was titrated at 0.05, 0.1, and 0.2 mg/kg s.c. against adult (trial 1) and at 0.05, 0.1, 0.14, and 0.2 mg/kg s.c. against immature (trial 2) stages of lung and gastrointestinal nematodes in cattle. in trial 1, every dose of subcutaneously delivered eprinomectin showed maximal or near-maximal (> or = 99%) efficacy against ha ...200111780839
production and characterization of a monoclonal antibody against recombinant saposin-like protein 2 of fasciola gigantica.a monoclonal antibody (moab) against recombinant fasciola gigantica saposin-like protein 2 (rfgsap-2) was produced by hybridoma technique using spleen cells from balb/c mice immunized with rfgsap-2. this moab is an igg1, κ light chain isotype. by immunoblotting and indirect elisa, the moab reacted specifically with rfgsap-2, the natural fgsap-2 at 10kda in whole body (wb) and excretory-secretory (es) fractions of f. gigantica. it did not cross react with antigens in wb fractions from other paras ...201323164839
field study on nematode resistance in nelore-breed cattle.the present study evaluated nelore cattle with different degrees of resistance to natural infections by gastrointestinal nematodes. one hundred weaned male cattle, 11-12 months of age, were kept on the same pasture and evaluated from october 2003 to february 2004. faecal and blood samples were collected for parasitological, haematological and immunological tests. in february 2004, the 10 most resistant and the 10 most susceptible animals were selected based on individual means of nematode faecal ...200717659839
gastrointestinal nematodes in indigenous zebu cattle under pastoral and nomadic management systems in the lower plain of the southern highlands of tanzania.this study aimed to determine the prevalence and intensity of gastrointestinal nematode infections in indigenous zebu cattle in the lower plain (lowland zone) of the southern highlands of tanzania. gastrointestinal tracts were randomly purchased at the iringa regional abattoir and at kihesa and ipogolo slaughter slabs in different seasons of the year. the contents of the abomasum, small intestine and large intestine were processed separately to recover the worms. the results indicated that 140 o ...200314509451
experimental infection of calves with haemonchus placei or haemonchus contortus: assessment of clinical, hematological and biochemical parameters and histopathological characteristics of abomasums.the present study had the primary objective of evaluating clinical, hematological and biochemical parameters, as well as observing anatomical and histopathological characteristics of abomasums, from calves prime-infected with haemonchus contortus or h. placei. ten male holstein newborns were subdivided in three groups (gi placebo; gii infected with h. contortus; giii inoculated with h. placei). eye mucosa staining was evaluated. hematological and biochemical tests were performed on animals. the ...201627693223
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
cytokine gene expression in response to haemonchus placei infections in nelore cattle.this study aimed to evaluate the expression of a subset of cytokine genes in response to haemonchus placei infections in nelore cattle presenting different degrees of resistance to natural infections. one hundred weaned bulls, initially 11-12 months old, were evaluated and kept on the same pasture. faecal and blood samples were collected for parasitological and immunological assays. the seven most resistant and the eight most susceptible animals were selected based on nematode faecal egg counts ...201020409640
fecal egg count reduction and control trial determinations of anthelmintic efficacies for several parasiticides utilizing a single set of naturally infected this study, a single set of naturally infected calves was used for the conduct of a fecal egg count reduction test (fecrt) immediately followed by a control trial; all, to evaluate the efficacies of several commonly used, non-generic anthelmintics. ten animals were allocated into each of the five treatment groups; untreated control (utc), injectable 1% moxidectin given at 0.2 mg kg(-1)bw (mxd), injectable 1% ivermectin given at 0.2 mg kg(-1)bw (ivm), 9.06% oxfendazole given orally at 4.5 mg k ...200919615822
a hybridisation technique to identify anthelmintic resistance genes in haemonchus.the identification of genes associated with anthelmintic resistance can be facilitated in haemonchus contortus by the ability of this species to hybridise with haemonchus placei. although the hybrid males are sterile, the lines can be rescued by backcrossing the females to either parental species. resistance genes can be retained in haemonchus hybrids, while the unwanted contortus background is removed through backcrossing to h. placei and anthelmintic selection of the progeny. under this select ...199910961854
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
[forming of gastro-intestinal nematodes fauna of free ranging european bison in bialowieza primeval forest during last 17 years (1984-2001)].28 european bison of both sexes and in different age shot in białowieza primeval forest in january 1984, (10 animals), january 1992 (10 animals) and in january and the beginning of february 2001 (8 animals) have been necropsied. the examined animals in mentioned years were of similar age. there were examined abomasa and duodena of shot animals. all necropsied bison were infected with gastro-intestinal nematodes. the highest intensity of infection with nematodes of abomasum was found in 1992 year ...200216894720
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
protection of calves against haemonchus placei and haemonchus contortus after immunization with gut membrane proteins from h. contortus.a vaccine containing integral membrane glycoproteins from the intestine of haemonchus contortus was evaluated in 4 groups of 9 worm free calves challenged with either 8,000 h. contortus or haemonchus placei infective larvae. vaccinates received 50 μg of the antigen and 1mg quila adjuvant three times 21 days apart, while the controls got adjuvant alone. the calves were challenged 7 days after the last immunization and killed for worm counts 43 days later. immunization resulted in high titre antib ...201121535018
experimental infection of calves with haemonchus placei and haemonchus contortus: assessment of parasitological parameters.the present study evaluated the viability and possible effects of haemonchus contortus infections in experimentally prime infected calves, comparing them to infections by haemonchus placei. ten male holstein newborns were used. all calves were individually weighed for subsequent group formation, in which two animals were kept as a control group, inoculated with water (gi); four animals were inoculated with 10,000 third stage (l3) haemonchus contortus larvae (gii); and the remaining four calves w ...201626827856
genetic diversity patterns of haemonchus placei and haemonchus contortus populations isolated from domestic ruminants in brazil.parasitic nematodes of the genus haemonchus infect a range of ruminant hosts and are of major veterinary and economic importance. in this study, the genetic variability of seven isolates of haemonchus placei and haemonchus contortus was evaluated using the mitochondrial gene cytochrome oxidase subunit i and the nuclear gene b-tubulin isotype 1. a total of 156 specimens were obtained from cattle, sheep, goat and buffalo herds raised on commercial properties from the southern and southeastern regi ...201222787588
differential in vitro pathogenicity of predatory fungi of the genus monacrosporium for phytonematodes, free-living nematodes and parasitic nematodes of vitro tests were carried out on the pathogenicity of nine isolates of the predatory fungi of the genus monacrosporium (5 m. sinense isolates, 3 m. appendiculatum and 1 m. thaumasium isolate) for a phytonematode (second stage juveniles from meloidogyne incognita, race 3), a free-living nematode (panagrellus spp), and two gastrointestinal parasitic nematodes of cattle (infective larvae of cooperia punctata and haemonchus placei). a suspension containing 2,000 nematodes from each species was add ...199910347773
a review of the epidemiology and control of gastrointestinal nematode infections in cattle in this review, the main gastrointestinal nematodes infecting cattle in zimbabwe and the epidemiological factors influencing their occurrence are reviewed and discussed. nineteen gastrointestinal nematode species that belong to seven families have been found to occur in cattle in zimbabwe. the main genera reported to date are cooperia, haemonchus, trichostrongylus and oesophagostomum and the dominant species are cooperia pectinata, cooperia punctata, haemonchus placei and trichostrongylus axei. ...201324396919
multispecies resistance of cattle gastrointestinal nematodes to long-acting avermectin formulations in mato grosso do sul.the use of long-acting avermectins (avms) in cattle to treat infections with gastrointestinal nematodes was common in brazil until its prohibition by state authorities. the prohibition; however, was rescinded in 2015, but a scientific discussion of the pros and cons of the use of these formulations is necessary. we evaluated the levels of resistance to 1.0 and 3.5% doramectin and to 3.15% ivermectin in cattle. the worms in animals treated with 3.5% doramectin were characterized by the suppressio ...201526129974
purifying selection and demographic expansion affect sequence diversity of the ligand-binding domain of a glutamate-gated chloride channel gene of haemonchus placei.ninety-five genomic sequences of the ligand-binding domain of glutamate-gated chloride channel genes of three populations of the parasitic nematode h. placei were evaluated for patterns of diversity, demography, and selection. these genes code for subunits of ion channels, which are involved in the mode of action of the most commonly used antiparasitic drugs, the macrocyclic lactones. an extremely high frequency of unique segregating sites in exons and introns was observed, with significantly ne ...200415114425
nematode resistance to ivermectin (630 and 700μg/kg) in cattle from the southeast and south of brazil.two high doses of ivermectin (630μg/kg and 700μg/kg) that are sold commercially in brazil were evaluated in dose-and-slaughter trials with 144 naturally nematode-infected cattle from eight regions within the states of minas gerias, são paulo and rio grande do sul in brazil. treatment groups were based on fecal egg counts 1, 2, and 3days before treatment; all animals studied had a minimum egg count of at least 500 eggs per gram of feces (epg). post-mortem analyses were conducted on day 14. the hi ...201425130588
differentiation of haemonchus placei from haemonchus contortus by pcr and by morphometrics of adult parasites and third stage larvae.molecular and morphological methods were evaluated to distinguish between haemonchus contortus and haemonchus placei species. a total of 141 h. contortus and 89 h. placei male adult specimens collected from artificially infected lambs were identified individually by pcr analysis, using a species-specific primer pair. these pcr results were used as gold standard for haemonchus spp. identification. haemonchus placei presented higher mean spicule and barb lengths than h. contortus (p<0.05). however ...201725517528
evaluation of clinical safety and anthelmintic efficacy of aurixazole administed orally at 24 mg/kg in cattle.the current study evaluated, in vivo, the clinical safety and the anthelmintic efficacy of 24% aurixazole (24 mg/kg), administered orally, in bovines. two experiments were conducted: the first one evaluating the clinical safety of 24% aurixazole (24 mg/kg) in cattle, and a second one evaluating the anthelmintic efficacy of aurixazole (24 mg/kg) against gastrointestinal nematodes on naturally infected cattle. based on the results of clinical safety, no alterations on clinical and haematological s ...201424656344
genetic evidence for hybridisation between haemonchus contortus and haemonchus placei in natural field populations and its implications for interspecies transmission of anthelmintic resistance.genetic hybridisation between parasitic nematode species has potentially important consequences. it could lead to the introgression of genes between species including those involved in pathogenicity, host specificity, transmission and drug resistance. it could also complicate diagnosis and control. however, there are few compelling examples of its occurrence in parasites in the field. haemonchus contortus and haemonchus placei are two closely related parasitic nematode species that predominantly ...201525449043
vaccination of grazing calves with antigens from the intestinal membranes of haemonchus contortus: effects against natural challenge with haemonchus placei and haemonchus similis.a vaccine containing integral membrane glycoproteins from the intestine of haemonchus contortus was evaluated in three groups of eight 5 months old grazing calves, naturally infected by haemonchus similis, haemonchus placei and other gastrointestinal nematodes. vaccinated calves received 5 or 50μg of the antigen and 1mg of saponin adjuvant, while the controls received adjuvant alone, initially three times, 3 weeks apart and then four more times at 6 weeks intervals. three weeks after the last im ...201424960373
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
the presence of benzimidazole resistance mutations in haemonchus placei from us cattle.haemonchus populations were collected from cattle from mid-western and eastern southern us (four and six populations, respectively) to determine the relative prevalence of haemonchus contortus and haemonchus placei and the frequency of the three isotype-1 β-tubulin polymorphisms associated with benzimidazole resistance. a minimum of 32 individual adult worms were genotyped at position 24 of the rdna its-2 for each population to determine species identity (296 worms in total). one population from ...201424916341
relative potency of macrocyclic lactones in in vitro assays with larvae of susceptible and drug-resistant australian isolates of haemonchus contortus and h. placei.the present study used in vitro assays to determine the relative potency of commercial macrocyclic lactone (ml) anthelmintics against larvae of drug-susceptible and drug-resistant australian isolates of important parasites of sheep and cattle, haemonchus contortus and haemonchus placei, respectively. cattle pour-on products containing abamectin, ivermectin, eprinomectin, doramectin or moxidectin were diluted in dmso and used in larval development assays. abamectin was the most potent chemical (l ...201424813746
experimental cross-infections of haemonchus placei (place, 1893) in sheep and examine effects on biology and morphology, haemonchus placei infections were propagated in cattle or sheep and infective larvae were introduced into the same or opposite host. ovine source larvae had a geometric mean (gm) prepatent period of 26.5 days regardless of host species, compared to 30.6 days for bovine source larvae regardless of host species. similarly, ovine source h. placei had a higher gm percentage establishment versus bovine source larvae (9.6% versus 3.4%) regardless of host s ...200111113549
control trial and fecal egg count reduction test determinations of nematocidal efficacies of moxidectin and generic ivermectin in recently weaned, naturally infected 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
evaluation of the persistent activity of moxidectin (10%) long-acting (la) injectable formulation against dictyocaulus viviparus, haemonchus placei, trichostrongylus axei and oesophagostomum radiatum infections in cattle.two controlled studies were conducted to evaluate the persistent efficacy of moxidectin (10%) long-acting (la) injectable formulation against dictyocaulus viviparus, haemonchus placei, trichostrongylus axei and oesophagostomum radiatum in cattle. the moxidectin la injectable formulation was administered as a single subcutaneous injection into the proximal third of the ear at a dose rate of 0.01ml/kg bw to provide 1.0mg moxidectin/kg bw. the product had persistent efficacy of >90% against d. vivi ...201019896772
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
can haemonchus placei-primary infected naïve lambs withstand haemonchus contortus infections?an experiment was conducted with the objective of evaluating whether a 5000 l3 larvae haemonchus placei primary infection, a less pathogenic parasite species for sheep, could attenuate highly pathogenic haemonchus contortus infections in lambs. thirty nine 6-month-old lambs were divided in three primary-infection groups: (hcpi) h. contortus-primary infected lambs, (hppi) h. placei-primary infected lambs, and (ctrl) non-infected control lambs. later, these same individuals, then aged 10-month old ...201728391070
mrna profile of nellore calves after primary infection with haemonchus placei.haemonchus parasites are responsible for many losses in animal production. however, few studies are available, especially of zebu cattle. in this study, we investigated mrna differences of immune response genes in naïve nellore calves infected with haemonchus placei, relating these differences to patterns of cellular infiltrate. calves were infected with 15,000 h. placei l3 larvae and after 7 days lymph node and abomasum tissues were collected. il-2, il-4, il-8, il-12, il-13, ifn-γ, mcp-1, lysoz ...201021144661
immune response to haemonchus contortus and haemonchus placei in sheep and its role on parasite specificity.two trials were conducted to determine the prepatent and the patent period of haemonchus contortus and haemonchus placei in santa ines crossbred sheep and to determine whether serial infections with both species confer protection against homologous or heterologous challenge. to evaluate the prepatent and patent periods of infection, five lambs received a single infection with 4000 h. contortus-infective larvae (l3), and another five received a single infection with 4000 h. placei l3. h. contortu ...201424670867
pcr primers for straightforward differentiation of haemonchus contortus, haemonchus placei and their hybrids.haemonchus contortus and haemonchus placei are among the major parasites of small ruminants and cattle. although infection with these nematodes is host-specific, with h. placei predominating in cattle and h. contortus in sheep, cross-infections are observed in areas where both parasites are sympatric, and hybrid offspring can occur. therefore, a fast and precise method is required for differentiating the parasites. identification based on spicule morphometry is the most common technique for diff ...201728069083
the identification of haemonchus species and diagnosis of haemonchosis.diagnosis is often equated with identification or detection when discussing parasitic diseases. unfortunately, these are not necessarily mutually exclusive activities; diseases and infections are generally diagnosed and organisms are identified. diagnosis is commonly predicated upon some clinical signs; in an effort to determine the causative agent, identification of genera and species is subsequently performed. both identification and diagnosis play critical roles in managing an infection, and ...201627238005
why is it important to correctly identify haemonchus species?parasitic gastroenteritis caused by haemonchus spp. is a major cause of economic losses in the livestock industry because it impairs weight gain and increases mortality in cattle and small ruminants, especially in tropical and subtropical areas. the proper identification of the various species, as well as knowledge regarding the epidemiology of parasitic gastroenteritis, is essential for the establishment of sustainable strategies of parasite control. this review focuses on the use of easily app ...201122166378
therapeutic and persistent efficacy of moxidectin 1% nonaqueous injectable formulation against natural and experimentally induced lung and gastrointestinal nematodes in cattle.four controlled trials were conducted to evaluate the therapeutic and persistent efficacy of a new moxidectin formulation (moxidectin 1% nonaqueous injectable) against nematode parasites in cattle. this injectable moxidectin formulation, given as a single subcutaneous injection at a dose rate of 0.02 ml/kg bw to provide 0.2 mg moxidectin/kg bw, was highly efficacious (>90-100%) against larval and/or adult stages of many species of nematodes in cattle including, dictyocaulus viviparus, ostertagia ...200415063941
influence of massive and long distance migration on parasite epidemiology: lessons from the great wildebeest migration.very little is known about the influence of massive and long distance migration on parasite epidemiology. migration can simultaneously minimize exposure to common parasites in their habitats and increase exposure to novel pathogens from new environments and habitats encountered during migration, while physiological stress during long distance movement can lead to immune suppression, which makes migrants vulnerable to parasites. in this paper, we investigated the diversity, prevalence, parasite l ...201627554373
the effect of gastrointestinal nematode infection level on grazing distance from dung.avoiding grazing near feces is an efficient strategy to prevent parasitic infection and contamination; therefore, in the evolution of herbivorous species, this behavior may have developed as a mechanism to protect the host against infection by gastrointestinal nematodes. the aim of this study was to assess whether grazing distance from dung is related to the level of parasitic infection in cattle. based on fecal egg count (fec) means, 18 castrated male steers, aged 18 months, were divided into t ...201526039729
anthelmintic resistance in gastrointestinal nematodes from grazing beef cattle in campeche state, mexico.production of beef cattle is one of the most important economic activities in mexico. however, anthelmintic resistance (ar) has affected animal productivity. the aim of this study was to determine the presence of ar in gastrointestinal nematodes (gin) of beef cattle in candelaria municipality of campeche state, mexico. sixty-five-month-old beef calves were selected for the faecal egg count reduction test (fecrt) and the inhibition of egg hatch (ieh) assay. these parameters were determined using ...201525876195
absence of detectable benzimidazole-resistance associated alleles in haemonchus placei in cattle in nigeria revealed by pyrosequencing of β-tubulin isotype 1.trichostrongyles are gastrointestinal parasites that occur globally and can cause subclinical to severe, sometimes life-threatening, infections in ruminants, particularly young animals. benzimidazoles (bz) are commonly used for the treatment of gastrointestinal parasites in ruminants. increasing spread of worm populations with anthelmintics resistance has been reported and is considered a consequence of highly frequent and longstanding use of anthelmintics. to obtain initial information regardin ...201525782679
p-gp modulating drugs greatly potentiate the in vitro effect of ivermectin against resistant larvae of haemonchus placei.since its production in the 1980s, ivermectin (ivm) has been used indiscriminately and the selection pressure to which bovine gastrointestinal nematodes have been exposed has been intense, resulting in considerable economic losses due to parasitic resistance. one possibility for the control of resistant parasites is the use of p-glycoprotein (p-gp) modulators, because one of the main biochemical changes in ivermectin-resistant parasites is the increased activity of membrane proteins responsible ...201425178553
unexpected occurrence of haemonchus placei in cattle in southern western australia.haemonchus placei is an abomasal parasite of cattle, primarily in tropical and subtropical areas of the world. in australia, this nematode can be extremely pathogenic in summer rainfall areas, particularly in the hot, sub-tropical kimberley region, in the far north of the state of western australia (wa). although cattle are occasionally transferred to southern parts of wa, it was believed that h. placei did not occur in southern regions of wa, as it is less cold-adapted than haemonchus contortus ...201424189197
the use of nemabiome metabarcoding to explore gastro-intestinal nematode species diversity and anthelmintic treatment effectiveness in beef 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
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