Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| anthelmintic efficacy of albendazole in cattle: comparison of critical and controlled tests. | twelve calves were experimentally inoculated with 6 species of gastrointestinal nematodes and the liver fluke, fasciola hepatica. six calves were administered albendazole at 10 mg/kg of body weight, and the drug efficacy was determined by critical and controlled tests. albendazole was only 74% effective against haemonchus contortus (cambendazole-resistant strain), 99 to 100% effective against ostertagia ostertagi, trichostrongylus colubriformis, cooperia oncophora, and oesophagostomum radiatum, ... | 1977 | 334003 |
| the digestive utilization of the diet in calves experimentally infected with ostertagia ostertagi. | the experimental infection of calves with 250,000 l larvae of ostertagia ostertagi per animal did not produce great variations in the digestibility of the diet administered. the infection retarded normal growth the resulted in an unfavourable conversion index. | 1977 | 560346 |
| cryopreservation of the infective larvae of the common nematodes of ruminants. | exsheathed infective larvae (l 3) of 19 species of nematodes were tested for infectivity in either sheep or cattle after they had been frozen in 0,9% nacl solution, stored for a relatively short time in the gas phase of liquid nitrogen and subsequently thawed. in addition, 13 of these species were tested after similar storage for up to 18 months. in sheep, haemonchus contortus, ostertagia circumcincta, trichostrongylus axei, trichostrongylus colubriformis, nematodirus spathiger and oesophagostom ... | 1977 | 566412 |
| in vitro cultivation of ostertagia ostertagi, the medium stomach worm of cattle. i. development from infective larvae to egg-laying adults. | when a 70-min exsheathing process and two-step roller culture system were used, infective larvae of ostertagia ostertagi developed in large numbers to mature adult males and females in 28 and 29 days, respectively. females laid fertile eggs in the 2- to 16-cell stages from day 34 on. some of the expelled eggs developed to the morula stage, in the culture fluid, by day 52. yields of mature adults and eggs were best when cultures were started with 100,000 larvae in 100 ml of medium. the optimal cu ... | 1977 | 864570 |
| action of fenbendazole on arrested fourth stage larvae of ostertagia ostertagi. | 1977 | 898643 | |
| recovery of infective 3rd stage larvae of haemonchus contortus and ostertagia ostertagi by migration in agar gel. | 1977 | 910655 | |
| influence of ostertagia ostertagi and cooperia infections on the energetic efficiency of steers fed a concentrate ration. | studies on effects of subclinical parasitism (low worm burden) in full-fed and maintenance-fed steers indicated that over a short interval low worm burdens do not have a statistically significant effect on the efficiency of energy utilization. in full-fed steers, energy retention tended to be higher in steers with lower worm burdens (mean 95.8 ostertagia, 12.5 cooperia) than in those with higher worm burdens (mean 677.5 ostertagia, 201.8 cooperia). maintenance-fed steers generally had larger num ... | 1977 | 911083 |
| the activity of fenbendazole against inhibited 4th stage larvae of ostertagia ostertagi [ letter]. | 1977 | 919274 | |
| anthelmintic activity of albendazole against gastrointestinal nematodes in calves. | anthelmintic activities of albendazole were evaluated in a controlled experiment. forty calves experimentally infected with gastrointestinal nematodes were allotted to 4 groups. calves in group 1 were used as nonmedicated controls; calves in groups 2, 3, and 4 were given (by oral route) a suspension containing albendazole at dose concentrations of 2.5, 5.0, and 7.5 mg/kg of body weight on the 35th day after administration of infective nematode larvae. in groups 2, 3, and 4 calves, average overal ... | 1977 | 921039 |
| density-dependent survival in populations of ostertagia ostertagi. | 1977 | 924718 | |
| anthelmintic efficacy of oxfendazole in calves. | oxfendazole, methyl [5-(phenylsulfinyl)-1h-benzimidazol-2-yl]carbamate given to calves at dose level of 2.5 mg/kg as a paste, as a bolus, or as a drench resulted in excellent (97 to 100%) anthelmintic efficacy against mature ostertagia ostertagi, trichostrongylus axei, cooperia oncophora, c mcmasteri, c pectinata, c punctata, nematodirus helvetianus, trichostrongylus longispicularis, chabertia ovina, and oesophagostomum radiatum. against the early 4th stage larvage of o ostertagia and n helvetia ... | 1978 | 567947 |
| plasma pepsinogen levels in some experimental infections of ostertagia ostertagi in cattle. | two groups of calves were infected with larvae of ostertagia ostertagi to establish large numbers of adults and arrested larvae. in one group symptoms of ostertagiasis were seen and there was a loss of three months growth; in the other, in which adult worms were removed by a single anthelmintic treatment, there was only a transient reduction in live-weight gain. plasma pepsinogen levels were however the same in the two groups and followed the same course. even after 25 weeks, when calves had bee ... | 1978 | 570316 |
| arrested development of ostertagia ostertagi and cooperia oncophora: effect of the time of year on the conditioning and deconditioning of infective larvae. | 1978 | 621298 | |
| the effect of diet on the establishment and growth of ostertagia ostertagi in calves. | three groups of four calves were raised parasite-free. each group received a different diet. at the moment of infection one group was fed with milk equivalent artificially dried grass, and concentrates, the second with water, grass pellets (16 mm), and concentrates, while the third was fed with water, artificially dried grass, and concentrates. each animal was infected at an age of 8 weeks with 10,000 larvae of ostertagia ostertagi and necropsied 28 days later, no significant differences between ... | 1978 | 644564 |
| activity of oxfendazole against inhibited larvae of ostertagia ostertagi and cooperia oncophora. | 1978 | 644827 | |
| factors involved in the relative anthelmintic tolerance of arrested 4th stage larvae of ostertagia ostertagi. | 1978 | 644835 | |
| anthelmintic activity of fenbendazole against gastrointestinal nematodes in calves. | anthelmintic activities of fenbendazole were evaluated in a controlled experiment. forty calves artificially infected with gastrointestinal nematodes were allotted to 4 groups. calves in group 1 were used as nonmedicated controls; the other calves were given (orally) fenbendazole at the dose level of 5 mg/kg in the forms of a suspension (group 2), medicated feed to individual calves (group 3), and medicated feed to the group (group 4). these treatments were given on day 35 after calves were inoc ... | 1978 | 677528 |
| autumn and winter fenbendazole treatment against inhibited 4th stage ostertagia ostertagi larvae in cattle. | 1978 | 706122 | |
| the length of ostertagia ostertagi in populations of uniform age. | 1978 | 748215 | |
| in vitro and in vivo studies on the ovicidal activity of fenbendazole. | the in vitro ovicidal activity of fenbendazole against eggs of ostertagia ostertagi, haemonchus contortus and trichostrongylus colubriformis was observed using different concentrations of active principle. the optimum concentration for ovicidal activity is evidently 0.5 ppm fenbendazole. a further increase in concentration results in a decrease in activity which is probably due to physical causes. ovicidal activity of the product is assessed by the proportion of non embryonated eggs as well as e ... | 1978 | 749077 |
| [effect of fenbendazole (panacur) against suppressed stages of dictyocaulus viviparus and ostertagia ostertagi in calves]. | 1978 | 152108 | |
| concurrent daily infection of calves with fasciola hepatica and ostertagia ostertagi. | three groups of calves were infected daily with either 1500 ostertagia ostertagi larvae, 20 fasciola hepatica metacercariae, or 1500 o ostertagi plus 20 f hepatica metacercariae. weekly measurements were taken of calf weight, faecal egg output, plasma concentrations of albumin, plasma activities of sorbitol dehydrogenase, gamma glutamyl transpeptidase and pepsinogen and standard haematological indices. calves were killed either 10 or 21 weeks after daily infections began. f hepatica infection ha ... | 1978 | 34850 |
| observations on crystals found in the intestinal cells of haemonchus contortus and in the intestinal lumen of ostertagia ostertagi. | 1978 | 204587 | |
| ostertagiosis in captive bison in new york state: report of nine cases. | type ii ostertagiosis was found at necropsy in 9 american bison (bison bison) from 3 farms in new york. clinical signs included severe diarrhea, emaciation, unthrifty coats, anemia, and weakness. in severely affected animals, the macroscopic abomasal changes consisted of irregular thickening and edema of the mucosa, resulting in a pebbly or morocco-leather appearance. microscopically, many gastric pits and glands were dilated, lined by hyperplastic epithelium, and contained nematode sections or ... | 1979 | 157257 |
| efficacy of albendazole for treatment of naturally acquired nematode infections in washington cattle. | albendazole, methyl 5-propylthio-1h-benzimidazol-2-yl carbamate, was given as a bolus (7.68 to 8.18 mg/kg of body weight) to cattle naturally infected with gastrointestinal nematodes and lungworms in a controlled trial. over 99% of adult ostertagia ostertagi, trichostrongylus longispicularis, cooperia oncophora, nematodirus helvetianus, and dictyocaulus viviparus were removed by the treatment. efficacy against immature o ostertagi, early fourth-stage o ostertagi, and oesophagostomum radiatum was ... | 1979 | 157705 |
| the efficacy of fenbendazole at a dosage rate of 7,5 mg/kg against nematode infestations in cattle. | fenbedazole, dosed to artificially infested cattle at 7,5 mg/kg live mass, was more than 80% effective in more than 80% of the treated animals against immature and adult haemonchus placei, ostertagia ostertagi; cooperia spp., bunostomum phlebotum and oesophagostomum radiatum. | 1979 | 162147 |
| [helminth fauna of syrian cattle]. | in this work the stomach and the small intestine of 34 and the large intestine of 4 more cattle were examined. 91,17% of the examined cattle (31 in 34 animals) had infected the stomach and/or the small intestine by parasites. 14 kinds of nematodes were found. the average intensity of infection of the stomach was higher than that of the small intestine. with the exception of higher infection in 3 stomachs and 2 small intestines the intensity of infection in all other cases was from small to mediu ... | 1979 | 453633 |
| avermectins, new family of potent anthelmintic agents: efficacy of the b1a component. | when given to sheep as a single oral dose at 0.1 mg/kg, the b(1a) component of the avermectins caused a reduction of >95% in the numbers of haemonchus contortus, ostertagia circumcincta (including inhibited l(4) larvae), trichostrongylus axei, trichostrongylus colubriformis, cooperia oncophora, and oesophagostomum columbianum. when given to cattle as a single oral dose at 0.1 mg/kg, avermectin b(1a) was >95% effective in reducing the numbers of haemonchus placei, ostertagia ostertagi (including ... | 1979 | 464563 |
| anthelmintic efficiency of oxfendazole, fenbendazole and levamisole against naturally acquired infections of ostertagia ostertagi and trichostrongylus axei in cattle. | the anthelmintic efficiencies of oxfendazole, fenbendazole and levamisole, each at 4 dose rates spanning the manufacturers' recommended dosages were compared in beef cattle with naturally acquired infections of ostertagia ostertagi and trichostrongylus axei. in 8 of the 9 cases tested there was no significant increase in anthelmintic efficiency due to increased dose rates of any of the drugs. percentage efficiencies and their standard errors, calculated from mean worm counts of pooled data for a ... | 1979 | 464935 |
| efficacy of oxfendazole against inhibited ostertagia ostertagi in naturally infected cattle. | oxfendazole was administered to pregnant cows at 2.5 and 5 mg/kg body weight to determine the anthelmintic efficacy against naturally acquired larvae which became inhibited at the early 4th stage. the experimental design included three groups of orally-treated cows, that is, 10 placebo treated control cows, 11 cows treated with 2.5 mg/kg of oxfendazole and 10 cows treated with 5.0 mg/kg of oxfendazole. oxfendazole at 2.5 mg/kg body weight was 82 and 94% effective against el-4 and adult o. ostert ... | 1979 | 475680 |
| activity against ostertagia ostertagi of low doses of oxfendazole continuously released from intraruminal capsules in cattle. | slow release from intraruminal capsules of 0.48 mg/kg oxfendazole per day for 5.5 days gave percentage efficiencies of 99 +/- 0.6, 86.6 +/- 6.3 and 93.1 +/- 4.5 for the removal of adult worms, developing 4th stages and inhibited larvae of ostertagia ostertagi respectively. these efficiencies were not significantly different from those obtained from a single oral dose of 2.5 mg/kg. peak plasma levels of oxfendazole were similar for the 2 types of administration but high levels were maintained lon ... | 1979 | 475682 |
| the activity of albendazole against adult and larval gastrointestinal nematodes in naturally infected calves in the netherlands. | the activity of albendazole against gastrointestinal helminths in naturally infected calves in the netherlands was tested. the calves were in their first 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 made. ten cal ... | 1979 | 494213 |
| seasonal transmission of bovine gastrointestinal nematodes in the texas gulf coast. | sentinel calves were placed in pastures for 1 month in two environmentally dissimilar areas of the texas gulf coast to determine the seasonal transmission of various gastrointestinal nematodes. transmission was determined for cooperia spp, haemonchus placei, ostertagia ostertagi, and trichostrongylus axei. large numbers of cooperia spp were acquired from may through november, with the peak of transmission occurring in july and august. haemonchus placei was encountered on both field sites but was ... | 1979 | 500427 |
| on the possible role of earthworms in the transmission of ostertagia ostertagi third-stage larvae from feces to soil. | 1979 | 512781 | |
| observations on ostertagiasis in young cattle over two grazing seasons with special reference to plasma pepsinogen levels. | the epidemiology of ostertagiasis in south west scotland was studied in groups of cattle grazed through two successive grazing seasons separated by a period of winter housing. towards the end of the first grazing season (september) the numbers of infective larvae (l3) on the pasture had increased to high levels (up to 24,000 l3 per kg) which resulted in high faecal egg counts, worm burdens, plasma pepsinogen levels and the occurrence of clinical ostertagiasis in the calves. by late spring (may) ... | 1979 | 524707 |
| the effect of a preparturient fenbendazole treatment on lactation yield in dairy cows. | studies carried out on nine farms in north-west england indicated that fenbendazole treatment of adult winter calving dairy cows in the dry period caused an overall increase of 173 kg in their subsequent lactation yield. there was some evidence to suggest that a correlation existed between pasture ostertagia ostertagi larval burdens and subsequent serum pepsinogen and milk yield responses post treatment. marked interherd and regional differences existed in the milk yield response to anthelmintic ... | 1979 | 524709 |
| gastrointestinal nematode immunization trials in cattle. | three experiments were conducted to immunize calves against ostertagia ostertagi, trichostrongylus axei, and t colubriformis. calves were given intraperitoneal injections with in vitro-grown parasitic larvae of the three species and iv and intraperitoneal injections of exoantigens obtained from culture media used to grow o ostertagi. none of the treatments provided immunity to subsequent oral challenge exposure with normal infective larvae. | 1979 | 525900 |
| activity of fenbendazole against inhibited early fourth-stage larvae of ostertagia ostertagi. | the efficacy of fenbendazole (panacur, hoechst-roussel) against inhibited early fourth-stage larvae of ostertagia ostertagi and other nematodes of the abomasum and intestinal tract was investigated in naturally infected, yearling cattle in april 1978. the time when peak levels of inhibited larvae occurred was determined by epizootiologic study which began in november 1977. all animals were removed from pasture and maintained free from further helminth infection until slaughter (19 to 21 days). t ... | 1979 | 525912 |
| anthelmintic activities of b1a fraction of avermectin against gastrointestinal nematodes in calves. | anthelmintic activities of the b1a fraction of avermectin were evaluated in a controlled experiment. twenty 12-week-old calves artificially infected with gastrointestinal nematodes were allotted to four groups. calves in group 1 were used as nonmedicated controls; other calves in groups 2, 3, and 4 were given (orally) b1a avermectin at dosage levels of 50, 100, and 200 microgram/kg of body weight, respectively. these treatments were given 35 days after calves were inoculated with infective nemat ... | 1979 | 525922 |
| the efficacy of thiophanate against gastrointestinal nematodes of cattle including inhibited larvae of ostertagia ostertagi. | 1979 | 532051 | |
| efficacy of anthelmintics against cattle nematodes. | the efficacies of fenbendazole and thiabendazole against artifically acquired cattle nematodes and the efficacies of fenbendazole, prabendazole and levamisole against naturally acquired cattle nematodes were studied in western victoria. fenbendazole significantly (p less than 0.05) reduced numbers of late and early fourth stage larvae (greater than 96%), artificially acquired cooperla spp (100%) and naturally acquired adult ostertagia ostertagi (98%) and trichostrongylus axei (90%). thiabendazol ... | 1979 | 533489 |
| the effect of age, acquired resistance, pregnancy and lactation on some reactions of cattle to infection with ostertagia ostertagi. | an experiment is described in which the effects of age, previous infection, pregnancy and lactation on some reactions of cattle to infection with ostertagia ostertagi were studied. it was found that an acquired resistance to the establishment of worms developed more rapidly in 20-month-old heifers than in calves, that it was unaffected by pregnancy of the host but that it was largely lost by heifers in early lactation. the rate at which populations were turned over, i.e. the mean life-span of wo ... | 1979 | 542317 |
| observations on the resumption of development of inhibited ostertagia, cooperia and nematodirus infections in calves stabled overwinter. | two groups of three month old, parasite-free calves grazed a permanently infected pasture for 14 days, group a during the first two weeks of september and group b during early november. half of each group was killed 14 days after removal from the pasture and the remainder stabled overwinter before slaughter and parasitological examination. marked inhibition of development occurred for cooperia oncophora with a variable lower level of inhibition for ostertagia ostertagi and practically none for n ... | 1979 | 548165 |
| bovine ostertagiasis: a changing epidemiological pattern? | an unusual epidemiological pattern in bovine ostertagiasis is described in which clinical ostertagiasis occurred in calves grazed on a silage aftermath from late july. the calves were treated with the anthelmintic levamisole prior to grazing the aftermath and the latter had not been grazed since the previous autumn. analysis of the herbage larval counts suggests that delayed emergence of overwintered ostertagia ostertagi l3 from the soil was the most likely source of the infection. | 1979 | 555116 |
| a prediction model for bovine ostertagiasis. | a mathematical model based on development and mortality rates, and incorporating data on the infectivity, fecundity and migratory behaviour of ostertagia ostertagi, was used to predict the level of pasture contamination and the occurrence of clinical ostertagiasis in grazing calves during 1975 and 1976. a comparison of the predicted and observed events showed a good correlation. | 1979 | 555121 |
| 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 ... | 1979 | 22039826 |
| studies on the epidemiology of ostertagia ostertagi in calves. | 1980 | 7360619 | |
| recovery of dead early fourth stage ostertagia ostertagi following benzimidazole administration. | 1980 | 7361398 | |
| ostertagia ostertagi infection and reinfection in cattle of different ages. | twelve cattle, three per group, were each inoculated orally with 100,000 ostertagia ostertagi infective larvae when they were 2 months, 4.5 months, 12 months, and 24 months-old, respectively. signs of clinical parasitism did not develop through 30 days when the infections were terminated with an anthelmintic. the cattle were each reinoculated with 500,000 o ostertagi larvae 6 days later. groups i to iii then developed anorexia and diarrhea after 3 weeks. one calf, inoculated at 2 months of age, ... | 1980 | 7369596 |
| studies on the effect of treatment with anthelmintics on weight gain in calves, naturally infected with gastrointestinal nematodes. | to avoid disease outbreaks caused by gastro-intestinal nematodes different prophylactic measures are recommended. in this connection pasture hygienic achievements and anthelmintics are used. in practice it is often difficult to realize pasture hygienic steps as move the animals to parasite free areas and to avoid that they come back to the infected. in many cases the parasite control is limited to routine deworming. our intention was to study if anthelmintic treatment without other measures had ... | 1980 | 7433013 |
| seasonal availability of nematode larvae on pastures grazed by cattle in new south wales. | trends in the numbers of infective menatode larvae on pasture plots contaminated by cattle at different seasons of the year were defined in 3 different climatic regions. the main nematodes were ostertagia ostertagi, trichostrongylus spp, haemonchus spp and cooperia spp. on the north coast of new south wales with a sub-tropical climate, the numbers of infective larvae of all 4 nematodes rose rapidly to peak levels soon after each seasonal period of contamination began, then fell quickly within a ... | 1980 | 7436894 |
| seasonal changes in the structure of nematode populations of cattle in new south wales in relation to inhibited larval development. | pasture plots in 3 climatic regions were contaminated with worm eggs of ostertagia ostertagi, trichostrongylus axei, haemonchus spp and cooperia spp in the autumn, winter and spring. successive pairs of parasite-free calves were grazed on the plots for 7 to 10 days at 4-week intervals and then killed for worm counts 14 days after their removal from pasture. on the northern tablelands of new south wales, irrespective of the season of pasture contamination, the degree of inhibition of o. ostertagi ... | 1980 | 7436895 |
| survival and development of larvae of the common nematodes of ruminants after long-term cryopreservation and investigation of different routes of infestation. | exsheathed infective larvae (l3) of 16 species of nematodes were tested for infectivity in either sheep or cattle after they had been frozen and stored in 0,09% nacl solution in the gas phase of liquid nitrogen for periods of up to 59 months. a mean of greater than 90% of the l3 of haemonchus contortus, ostertagia circumcincta, trichostrongylus axei, trichostrongylus colubriformis, nematodirus spathiger, oesophagostomum columbianum and chabertia ovina of sheep and haemonchus placei, ostertagia o ... | 1980 | 7465164 |
| persistence on pasture of the infective larvae of nematodes parasitizing maine dairy cattle. | yearling calves infected with ostertagia ostertagi, cooperia oncophora, and nematodirus helvetianus were allowed to graze on a 0.8 ha pasture plot contaminated during june and august 1977. in june 1978, the plot was subdivided into 10 subplots of equal size. grazing in 5 of these plots was allowed, each for 1 month, during june, july, august, september, and october by groups of 2 parasite-free 16-week-old calves. the procedure was repeated in 1979 with the remaining 5 subplots. each group of cal ... | 1980 | 7224300 |
| efficacy of avermectin b1a for treatment of experimentally induced nematode infections in cattle. | two formulations of avermectin b1a, c-076 and mk-933, were examined for anthelmintic activity in two trials, each using 20 calves with experimentally produced nematode infections. in one trial, c-076 was given orally, and in the other trial, mk-933 was given by injection at dosages of 50, 100, and 200 micrograms/kg of body weight. treated calves were held for 7 to 8 days and then, together with nontreated controls, were euthanatized and were examined for nematodes in their gastrointestinal tract ... | 1980 | 6449894 |
| quantitative modelling and prediction of development times of the free-living stages of ostertagia ostertagi under controlled and field conditions. | the development of the free-living stages of ostertagia ostertagi incubated at constant temperatures from 5 to 27 degrees c and in dung pats in the field was observed. the death rates were adequately described by a single exponential functional and the distribution of times for development by a delayed gamma density function. the times of appearance of selected development stages such as maximum numbers of embryonated eggs and half the maximum number of infective larvae, were highly dependent on ... | 1980 | 7232030 |
| anthelmintic efficiency of ivermectin against naturally acquired bovine gastrointestinal nematodes. | ivermectin, one of the new avermectin group of anthelmintics, was more than 99 per cent effective in removing all stages of ostertagia ostertagi including inhibited larvae, and adult trichostrongylus axei when administered to cattle orally at 100 microgram/kg body-weight or subcutaneously at 100 and 200 microgram/kg body-weight. high efficacy (> 98.6 per cent) was also obtained against adults and inhibited larvae of cooperia oncophora at 100 microgram/kg orally or 200 microgram/kg by subcutaneou ... | 1980 | 6893775 |
| anthelmintic activities of ivermectin against gastrointestinal nematodes of cattle. | the anthelmintic efficacy of ivermectin, a combined solution of the b1a and b1b fractions of avermectin, was assessed in a controlled trial. twenty-four yearling calves experiencing naturally acquired, clinical gastrointestinal helminthiasis were evenly divided on the basis of weight into two 12-animal groups. the medicated group was given (subcutaneously) ivermectin at the dose rate of 200 microgram/kg of body weight. the control animals were given the vehicle alone, at an equivalent rate. all ... | 1981 | 6895007 |
| anthelmintic efficacy of 22,23-dihydroavermectin b1 against gastrointestinal nematodes in calves. | anthelmintic activities of 22,23-dihydroavermectin b1 (comprised to greater than or equal to 95% 22,23-dihydroavermectin b1a and less than or equal to 5% 22,23-dihydroavermectin b1b) against gastrointestinal nematodes in calves were evaluated in 2 controlled experiments. infective larvae of haemonchus contortus, ostertagia ostertagi, trichostrongylus axei, t colubriformis, cooperia oncophora, and c punctate were given to 11-week-old calves and oesophagostomum radiatum had been given 21 days earl ... | 1981 | 6895285 |
| efficacy of ivermectin against inhibited larvae of ostertagia ostertagi. | the efficacy of ivermectin against inhibited early 4th-stage larvae of ostertagia ostertagi and other nematodes of the abomasum and intestinal tract was determined in naturally infected yearling beef cattle. the time when large numbers of inhibited larvae were acquired was determined by monthly slaughter of monitor cattle, beginning in january. in april, 12 animals were removed from pasture and maintained free of further helminth exposure until slaughter (21 days). at 9 days after the cattle wer ... | 1981 | 6896120 |
| anthelmintic efficacy of ivermectin against immature gastrointestinal pulmonary nematodes of calves. | anthelmintic efficacy of ivermectin (greater than or equal to 80% 22,23-dihydroavermectin b1a and less than or equal to 20% 22,23-dihydroavermectin b1b) was evaluated in a controlled experiment against immature nematodes. twenty calves raised to about 8 weeks of age under nematode-free conditions were allocated into 4 groups. infective larvae of haemonchus contortus, ostertagia ostertagi, trichostrongylus axei, t colubriformis, cooperia oncophora, c punctata, oesophagostomum radiatum, and dictyo ... | 1981 | 6896121 |
| the removal of inhibited early fourth stage ostertagia ostertagi from yearling cattle by mk 933, an ivermectin formulation. | 1981 | 6946336 | |
| reduced activity of levamisole against ostertagia ostertagi in dairy calves. | levamisole bolus formulation was administered in single doses, at rates of 5.8 to 8.1 mg/kg body weight, in 3 controlled tests in male dairy calves (n = 22) in kentucky. removals of natural infections of adult ostertagia ostertagi were 70% and 76% for calves from a hear with a history of regular treatments with levamisole and 85% for calves from a herd receiving levamisole occasionally. activity against other abomasal nematodes and lungworms was also evaluated. | 1981 | 7038437 |
| effects on inhibition of development of the transfer of ostertagia ostertagi between geographical regions of australia. | pasture plots in a warm coastal region were separately contaminated in the autumn, winter and spring with eggs of a coastal strain of ostertagia ostertagi derived from dairy calves. at the same times, a parallel set of plots was contaminated by a strain transferred from within a beef cattle management system in a cooler tablelands region. a reciprocal transfer of the coastal strain was also made to the tablelands, where pasture plots were contaminated with eggs of both strains of o. ostertagi in ... | 1981 | 7243348 |
| experimental cross-infections with gastrointestinal nematodes of sheep and cattle. | five parasite-free lambs and five parasite-free calves were infected experimentally with 20,000 third stage gastrointestinal nematode larvae cultured from faeces of sheep from five different farms. in the same way five lambs and five calves were infected with larvae cultured from faeces of calves from five different farms. host specificity of the nematodes was determined using the following parameters: infection rate; number, size, and stage of the worms; their distribution within the gastrointe ... | 1981 | 7245840 |
| further studies on the efficacy of fenbendazole against inhibited larvae of ostertagia ostertagi. | fenbendazole, at low dosage levels, was evaluated for its efficacy against inhibited early fourth stage larvae of ostertagia ostertagi in naturally infected, yearling beef cattle in april. the mean number of inhibited larvae in 10 untreated control cattle was 51,500. at a dosage level of 1 mg per kg (pelleted fenbendazole) per day in feed over five days in 10 cattle, the percentage reduction in comparison to controls was: adults, 85.9 per cent; developing stages, 79.0 per cent; inhibited early f ... | 1981 | 7257120 |
| further observations on the action of fenbendazole against inhibited fourth stage larvae of ostertagia ostertagi. | two further trials are reported on the effect of fenbendazole on inhibited ostertagia ostertagi larvae. in the first trial fenbendazole successfully eliminated inhibited burdens of o ostertagi, while in the second trial the effect was variable. as a result of these trials and previous reports it is concluded that a single oral dose of fenbendazole cannot be relied upon to prevent winter (type 2) ostertagiasis. | 1981 | 7257135 |
| anthelmintic efficacy of albendazole against inhibited larvae of ostertagia ostertagi. | albendazole was evaluated for its efficacy against inhibited early 4th-stage larvae of ostertagia ostertagi for the 3rd consecutive year (april 1979) in naturally infected yearling beef cattle. mean numbers of o ostertagi developmental stages in 10 nontreated controls were: adults, 11,485; developing 4th-stage larvae, 1,370; and early 4th-stage larvae, 51,500. the mean proportion of inhibited early 4th-stage larvae was 76.8%. small numbers of haemonchus sp and trichostrongylus axei were uniforml ... | 1981 | 7258782 |
| the efficacy of fenbendazole at a dosage rate of 5 mg/kg against nematode infestations in cattle. | the anthelmintic efficacy of fenbendazole, dosed to artificially infested cattle at 5 mg/kg live mass was determined against immature and adult haemonchus placei. ostertagia ostertagi, cooperia spp., bunostomum phlebotomum and oesophagostomum radiatum. at this dosage rate, fenbendazole was more than 80% effective in more than 80% of the animals treated against the abovementioned nematodes. the only exception was against the third-stage larvae of b. phlebotomum when it fell to more than 60% effec ... | 1981 | 7265100 |
| inhibition of gastric hydrochloric acid secretions in the rat given ostertagia ostertagi (a gastric parasite of cattle) extract. | the immersion of freshly collected ostertagia ostertagi adults into saline solution (nacl, 0.9%; ph 1.0) resulted in 100% mortality of worms within a 10-minute period. at ph 7.0, mortality was 58% after 270 minutes. at ph 2.2, which approximates the usual abomasal ph, 100% mortality resulted within 60 minutes. in the stomach of rats injected with an extract of o ostertagi (from the abomasum of cattle), there were decreased total secretion of hydrogen ions and volume of secretion (p less than 0.0 ... | 1981 | 7271014 |
| efficacy of levamisole against abomasal nematodes and lungworms in dairy calves: preliminary tests indicating reduced activity for ostertagia ostertagi. | dairy calves (n = 18) were used in controlled tests to evaluate activity of levamisole against abomasal nematodes and lungworms. two formulations of levamisole, injectable (experiment a) and bolus (experiment b), were given in single doses at rates of 6 mg/kg of body weight and 5.4 to 10.2 mg/kg (5.4, 7.6, 8.0, 8.8, or 10.2 mg/kg), respectively. experiment a included 4 treated and 4 nontreated calves and experiment b consisted of 5 treated and 5 nontreated calves. aggregate removals of ostertagi ... | 1981 | 7271028 |
| seasonal occurence of infective nematode larvae on irrigated pasture grazed by cattle in california. | during the period extending from dec 1, 1975, to dec 22, 1976, 3 distinct peaks in the concentration of infective nematode larvae on pasture forage were detected by use of helminth-free tracer calves. two of these peaks, 1 occurring in the spring and 1 in the fall, consisted mainly of ostertagia ostertagi and cooperia sp. it is concluded that these 2 peaks can be anticipated annually and constitute unsafe periods of grazing. the 3rd peak was comprised largely of haemonchus placei and cooperia sp ... | 1981 | 7271041 |
| failure of white-tailed deer (odocoileus virginianus) to serve as experimental hosts for ostertagia ostertagi stiles, 1982. | 1981 | 7328473 | |
| ivermectin: controlled test of anthelmintic activity in dairy calves with emphasis on dictyocaulus viviparus. | twelve dairy calves, naturally infected with lungworms and gastrointestinal parasites, were selected for a controlled test with single doses of ivermectin, administered subcutaneously, at the dose rate of 200 micrograms/kg. specific interest was on efficacy of ivermectin against lungworms (dictyocaulus viviparus), with ancillary interest directed on abomasal parasites. ivermectin was administered to 6 calves, and the vehicle only, to 6 calves. at necropsy, 7 days after treatment, lungworms were ... | 1981 | 6455949 |
| the repellent effect of gastric contents from uninfected calves for sheathed and exsheathed larvae of ostertagia ostertagi. | 1981 | 7229812 | |
| worm burdens of dairy heifers in england and wales. | the size and composition of abomasal worm burdens from 143 casualty and cull dairy heifers were estimated. over 60 per cent had totals of less than 10,000, only four exceeded 100,000 and the overall mean was 16,285. ostertagia ostertagi was almost always present and usually formed the major proportion of the total. trichostrongylus axei was recorded in 83 heifers and was the most common species on 17 occasions. the numbers of arrested early fourth stage worms were highest in winter and declined ... | 1981 | 7197843 |
| 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 ... | 1981 | 22133071 |
| worm burdens in cows. ii. an analysis of the population of nematodes in the abomasa of adult dairy cows. | over a period of one year, from february 1979-february 1980, the abomasa of four dairy cows were examined each week for the presence of parasitic nematodes. based on the identification of adult male worms, ostertagia ostertagi (94%) and trichostrongylus axei (75%) were the most prevalent species, and haemonchus contortus was absent. total worm burdens varied from zero (one cow) to 100,890. the geometric mean total number was 3011. the geometric mean number of arrested larval stages was 685. of t ... | 1982 | 6890273 |
| gastrointestinal nematodiasis in dairy cattle. | infection with gastrointestinal nematode parasites appears to be widespread in the cattle population. the pathologically important genera of worms all belong to the family trichostrongylidae. the most pathogenic species is ostertagia ostertagi, which can produce profound changes in abomasal mucosa of affected animals. these nematodes show developmental adaptations, such as seasonally arrested development, that are of prime importance to their survival and persistence on a year to year basis. whe ... | 1982 | 6759538 |
| controlled test of the efficacy of the feed premix formulation of crufomate on the parasites of the gastrointestinal tract and lungs of dairy calves. | activity of the feed premix formulation (m-1839) of crufomate against helminths of the gastrointestinal tract and lungs of cattle was determined in a controlled test. eight calves were treated and 7 were nontreated. the dosage rate of crufomate was 17 mg of active drug/kg of body weight daily for 3 consecutive days. removal activity was high against mature cooperia oncophora (99%) and c punctata (96%) and immature cooperia spp (87%). removal of mature ostertagia ostertagi was 68%. the removal of ... | 1982 | 6213184 |
| evaluation of albendazole in cattle naturally infected with nematodes. | albendazole (7.5 mg/kg of body weight) was given to 10 calves naturally infected with gastrointestinal nematodes. ten similar calves served as controls. the compound provided 99% to 100% efficacy in removing haemonchus placei, ostertagia ostertagi, trichostrongylus axei, t colubriformis, nematodirus spathiger, n helvetianus, n filicollis, cooperia oncophora, c punctata, and oesophagostomum radiatum. | 1982 | 7073074 |
| ostertagia ostertagi in calves: a growth nitrogen balance and digestibility study conducted during winter feeding following thiabendazole anthelmintic therapy. | 1982 | 7085939 | |
| ostertagia ostertagi in calves: growth, nitrogen balance and digestibility studies conducted during winter feeding following different fenbendazole therapy programmes. | observations of growth, nitrogen (n) balance and digestibility were made during the first winter housing period upon three groups of calves which had previously been naturally infected with ostertagia ostertagi and which were left either untreated (a) or treated with fenbendazole on three occasions (b) or every two weeks during the entire grazing season (c). the diet given contained sufficient metabolisable energy but only about 60 per cent of the recommended crude protein to sustain a daily gro ... | 1982 | 7089384 |
| ostertagia ostertagi in calves: clinical parasitism and resistance. | 1982 | 7091854 | |
| inhibited development of ostertagia ostertagi in relation to production systems for cattle. | on a coastal farm in new south wales where beef and dairy cattle production was carried on side-by-side, separate pasture plots were contaminated with eggs of ostertagia ostertagi by calves from each production system in autumn, winter or spring. successive groups of parasite-free tracer calves grazed on the plots for 14 days at 4-week intervals and were then killed for worm counts 14 days after removal from pasture. on all plots, the proportion of inhibited early 4th-stage larvae in tracer calv ... | 1982 | 7122124 |
| inhibition of development of ostertagia ostertagi--effect of temperature on the infective larval stage. | populations of ostertagia ostertagi established from fresh larvae and from larvae stored at 4 degrees c for up to 12 weeks contained about 10% inhibited early 4th-stage larvae. this value rose to 21% after 16 weeks, due to an increase in numbers of inhibited larvae while adult numbers remained unchanged. storage at 15 degrees c had no effect. in the case of larvae stored at 4 degrees c for 8 weeks, increasing the larval dose to 90000 had no significant effect on the proportion of the dose which ... | 1982 | 7122125 |
| field study on the epidemiology and pathogenicity of different isolates of bovine ostertagia spp. | the epidemiological features of three different isolates of bovine ostertagia spp under similar initial levels of larval challenge were compared in the field. two of the isolates, consisting mainly of ostertagia ostertagi, and a low proportion of skrjabinagia lyrata conformed in epidemiological behaviour with those investigated by previous workers, though the worm burdens which established did not give rise to the expected clinical signs. the third isolate behaved in a different way, yielding ve ... | 1982 | 7156510 |
| anthelmintic efficacy of febantel against gastrointestinal helminths in calves. | three dosage levels of febantel were tested for anthelmintic activities in calves under field conditions. a total of 20 feeder calves affected with naturally occurring gastrointestinal parasites were used in the controlled test. the calves were allotted to 4 groups of 5 each on the basis of degree of parasitism, body weight, age, and sex. calves in groups ii through iv were treated with febantel paste formulation at dosage levels of 5, 7.5, and 10 mg/kg of body weight; calves in group i were use ... | 1982 | 7165174 |
| oxfendazole: anthelmintic activity in calves artificially infected with six species of nematodes and in calves naturally infested with tapeworms. | in a series of 5 trials, in which 115 artificially infected calves were used, larval anthelmintic tests were done to assess the activity of oxfendazole at 4, 5 mg/kg against all 3 parasitic stages of 6 species of namatodes. an efficacy of over 98% was demonstrated against the 4th stage larvae (l4), 5th and adult stages of haemonchus placei, ostertagia ostertagi, cooperia pectinata, bunostomum phlebotomum and oesophagostomum radiatum and the 3rd larval stage (l3) of h. placei and c. pectinata. ag ... | 1982 | 7175907 |
| [macro-baermann--a method for parasitological examination of herbage samples]. | a baermann technique for extraction of trichostrongylide larvae (l3) from herbage samples is described. the technique is a modification/simplification of a technique previously described by persson (1974). on examination of 150-200 g samples 30-60% of larvae of ostertagia ostertagi and cooperia oncophora were recovered. | 1982 | 7187483 |
| further tests of activity of levamisole on ostertagia ostertagi in dairy calves with notes on overwinter survival of gastrointestinal helminths on pasture. | two controlled tests were conducted in 1981 and 1982 in dairy calves on the university of kentucky research farm to determine activity of the bolus formulation of levamisole given at the dose rate of 8 mg/kg against naturally occurring infections of ostertagia ostertagi. removal efficacies of mature o ostertagi were 98% in the 1981 test (3 treated and 3 nontreated calves) and 94% in the 1982 test (7 treated and 8 nontreated calves). against immature ostertagia spp, removal efficacies were 100% a ... | 1983 | 6625330 |
| comparison of oral and intraruminal administration of oxfendazole against ostertagia ostertagi and cooperia oncophora. | 1983 | 6649379 | |
| persistent anthelmintic effect of ivermectin in cattle. | the persistent anthelmintic effect of ivermectin given subcutaneously at 200 mcg/kg was evaluated against induced infections of haemonchus placei, ostertagia ostertagi, cooperia spp. (c. pectinata and c. punctata), bunostomum phlebotomum and oesophagostomum radiatum in cattle. forty-four friesian bull calves raised under worm-free conditions were restrictively randomized to one untreated control group and 3 ivermectin treated groups of equal size according to mass. animals in the different treat ... | 1983 | 6689429 |
| therapeutic and prophylactic efficacy of morantel when administered directly into the rumen of cattle on a continuous basis. | the efficacy of morantel tartrate when administered on a continuous basis directly into the rumen/reticulum of cattle, either by a cannula or from a specially designed device, was evaluated against gastrointestinal parasites under laboratory conditions. in two experiments the continuous infusion of morantel at rates between 0.26 and 1.04 mg/kg body weight per day using a peristaltic pump was highly efficacious in both preventing the establishment of infections and removing established infections ... | 1983 | 6225238 |
| experimental and natural infection of calves with bunostomum phlebotomum. | an experiment was conducted to determine the efficiency of a method of experimental infection of weaner beef calves with bunostomum phlebotomum and to compare such infection with that established by natural infection. six calves, maintained on a concrete-floored pen, were inoculated with b. phlebotomum l3 by placing the larval inocuulum, in small volume, in the outer chamber of the ear while the animal was restrained for 18 min. inoculation doses of 20, 30, 40, 50, 60, and 80 thousand l3 were us ... | 1983 | 6229089 |
| enzyme-linked immunosorbent assay for the detection of antibodies to hypoderma bovis in cattle. | an adaptation of the enzyme-linked immunosorbent assay has been shown to detect antibodies in the circulation of cattle infected with hypoderma bovis. strong positive reactions were obtained from all infected cattle, even those which harboured only one larva. a strong cross reaction was observed in sera taken from cattle infected with h lineatum, but not in cattle infected with fasciola hepatica or ostertagia ostertagi. | 1983 | 6344168 |
| seasonal changes of gastrointestinal nematode populations in yearling beef cattle in louisiana with emphasis on prevalence of inhibition in ostertagia ostertagi. | 1983 | 6853015 | |
| epidemiological studies on ostertagia ostertagi infections in cattle during their first, second and third summer on pasture. | the number of ostertagia ostertagi in the abomasum of steers, that had been on pasture for one, two or three summers was determined. a total of 44 animals were examined and of these 12 had been out one summer 27 two summers, and five during three summers. during the grazing seasons plasma pepsinogen and serum albumin was determined on all the steers and on 24 heifers during their first summer on pasture. the mean number of parasites in the abomasum after one summer was 128,500 and at the end of ... | 1983 | 6889128 |
| serum pepsinogen levels and ostertagia ostertagi populations in clinically normal adult beef cattle. | serum pepsinogen levels and ostertagia ostertagi populations in clinically normal grass-fed bullocks were investigated in three groups of 10 prime cattle aged between 2.5 and 2.75 years slaughtered in late summer (february), early autumn (march) and late autumn (may) respectively. apart from occasional foci of mucosal hyperplasia abomasa were grossly normal. serum pepsinogen levels ranged between 0.2 and 2.5 i.u./l with group means of 1.4, l.5 and 1.3 i.u./l. o. ostertagi counts ranged between 0 ... | 1983 | 16030924 |
| [efficacy of albendazole as a pellet formulation against ostertagia ostertagi and cooperia oncophora in experimentally infected calves]. | 1984 | 6370654 |