morantel and Intestinal-Diseases--Parasitic

The efficacy of morantel sustained release trilaminate (MSRT) bolus against gastrointestinal nematodes was evaluated under field conditions over a 10-month period. Twenty weaner calves were randomly divided into 2 groups of 10 calves each and grazed from March to December on adjacent, similarly contaminated paddocks. Group 1 calves (T-1) served as untreated controls while group 2 calves (T-2) were dosed at turnout with MSRT bolus designed to release morantel tartrate continuously for 90 days. The efficacy of MSRT was assessed by comparison of parasitological data (faecal worm egg counts, herbage larval counts, worm counts from tracer calves and set-stocked trial calves, determination of haematological parameters and pepsinogen levels), weight gains and clinical status of the animals. Faecal egg counts from the treated group (T-2) were reduced by 100% (P < 0.001) following treatment and remained significantly (P < 0.05) lower than counts from T-1 calves up to trial termination. The use of MSRT bolus resulted in a reduction of 92% (P < 0.001) in the number of gastrointestinal nematodes in set-stocked calves at the end of the study and a 55 to 85.7% reduction in herbage larval infectivity as reflected in lowered parasite burdens in tracer calves. At the trial termination, the control calves had gained on average (+/- s.d.) 59.4 +/- 4.8 kg (200.0 +/- 7.4 g day-1) and the treated ones on an average 128.6 +/- 10.5 kg (530.0 +/- 13.1 g day-1).

Topics: Animals; Antinematodal Agents; Cattle; Cattle Diseases; Delayed-Action Preparations; Dose-Response Relationship, Drug; Fasciola; Fascioliasis; Feces; Female; Intestinal Diseases, Parasitic; Kenya; Morantel; Parasite Egg Count; Pepsinogens; Time Factors; Tropical Climate; Weight Gain

The direct and indirect anthelmintic efficacies of the morantel sustained-release bolus given to calves were assessed in a 154-day controlled field trial. A permanent calf pasture (divided into 2 lots) and naturally parasitized calves were used. The medicated calves were given the bolus at the time they were placed on the pastures. Control calves did not receive anthelmintic therapy. The effectiveness of the bolus to control parasitic gastroenteritis was determined by monitoring various parasitologic determinants. The treated calves had significantly (P less than 0.01) reduced numbers of fecal nematode eggs for every posttreatment sampling period when compared with the control calves. Tracer calves, used periodically during the study to indicate pasture larval infectivities, had equivalent worm burdens at the beginning of the trial (treated vs control pasture). Tracer calves, added later in the study to the lot with treated calves, harbored 83% to 94% fewer nematodes than did their counterparts in the lot with the controls. Plasma pepsinogen concentrations, reflective of abomasal worm burden size and/or activity, were significantly higher (P less than 0.01) in the control than in the treated calves from day 54 until trial termination. At trial termination, the treated calves weighed an average of 27.8 kg more and harbored 80.9% fewer nematodes than the control calves. The morantel sustained-release bolus is an anthelmintic delivery device that has therapeutic and prophylactic antinematode activities. To achieve its optimum performance, the bolus must be used so that the epizootiologic patterns of the predominate parasitic nematodes are effectively disrupted. Generally, internal nematode parasitisms in the calf flourish during the animal's first springtime grazing period.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Administration, Oral; Animals; Body Weight; Cattle; Cattle Diseases; Clinical Trials as Topic; Delayed-Action Preparations; Feces; Intestinal Diseases, Parasitic; Male; Morantel; Nematode Infections; Parasite Egg Count; Pepsinogens; Pyrimidines; Seasons; Species Specificity

A field experiment was carried out in Kolda (southern Senegal) from July 1986 to July 1988. Its goals were to: (1) describe the patterns of mortality of female Guinean goats by age, season and year; (2) assess preventive measures against respiratory diseases and gastrointestinal parasitism in reducing mortality; and (3) estimate the overall impact of these measures on survival to 1 year of age. Preventive measures for respiratory disease included vaccination against peste des petits ruminants (PPR) and pneumonic pasteurellosis (Pasteurella multocida types A and D). Control of gastrointestinal parasites was by deworming does with morantel (7.5mg kg(-1), three times during the rainy season). The effects of vaccines and deworming were tested in a randomised factorial field experiment with villages being the experimental units. A total of 19 villages, 113 goat herds and 1,458 goats were included in the study. Generalised linear models of survival for five cohorts of goats (defined by five different birth seasons) used a binomial assumption for the response distribution and a complementary log-log link. Explanatory variables included age, season, year, vaccination, deworming and their interactions. A complex a priori model was built on the basis of previous epidemiological knowledge; a purposely selected set of simpler models was compared to this full model by the Akaike information criterion (AIC) and derived statistics. Inference on 1-year survival and treatment effects accounted for model-selection uncertainty. It was carried out with a bootstrap procedure and used information from the whole set of selected models. Large variations in mortality by year and season were observed but no regular seasonal pattern was apparent. Mortality probabilities of kids in dewormed groups decreased quickly after birth, but remained elevated up to 9 months of age in the non-dewormed groups. Deworming lowered the risk of mortality. Vaccination alone was not protective (except during an observed outbreak of PPR).

Topics: Animals; Anthelmintics; Cohort Studies; Female; Goat Diseases; Goats; Intestinal Diseases, Parasitic; Linear Models; Morantel; Pasteurella multocida; Pasteurellosis, Pneumonic; Peste-des-Petits-Ruminants; Peste-des-petits-ruminants virus; Seasons; Senegal; Survival Analysis; Vaccination

The effect of the time of administration of the Paratect Flex -Bolus (PF-Bolus) on the course of infections with gastrointestinal nematodes was investigated in a field experiment with three groups of 9 first year grazing heifers in the Swiss midland region. The heifers of groups A and B received the PF-Bolus at turnout on May 7 (early season application) and on July 16 (late season application), respectively. The heifers of group C remained untreated. All heifers were grazed together throughout the experiment. The mean egg excretion of the heifers of group A remained very low for a period of 70 days and peaked at the end of September reaching a mean value of 167 eggs per gram of faeces (epg). After the administration of the PF-Bolus to the heifers of group B, the egg excretion was reduced by 97% and remained below 50 epg for the rest of the season. While the mean serum pepsinogen values of the heifers of groups A and B only reflected subclinical infections, the mean values of the heifers of group C exceeded 4400 mU tyrosine and 4 heifers exhibited signs of parasitic gastroenteritis. At the end of the experiment (Oct 8) heifers of group A were 14 kg heavier than the controls (not significant) whereas the heifers of group B outperformed the control heifers by 20 kg (significant, p > 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Cattle; Cattle Diseases; Drug Administration Schedule; Female; Intestinal Diseases, Parasitic; Morantel; Nematode Infections; Seasons

In the alpine region, mixed grazing systems with cattle of different age, origin and prophylaxis against trichostrongylid infections are most common. Under these conditions the administration of anthelmintic devices to susceptible calves is frequently postponed to June or July to achieve a better protection during the period of increased pasture infectivity in summer and autumn. In a field experiment with 27 first-year grazing calves a morantel sustained-release trilaminate bolus (MSRT, Pfizer) was given to two groups (Groups A and B) of nine naturally infected calves each, on 22 July. Calves of Group B were moved to a clean pasture (B) 1 day later, whereas the calves of Group A remained on the previous pasture (A) together with nine untreated calves (Group C). The contamination with infective larvae (L3) on Pasture A remained below 1000 L3 kg-1 dry matter, which was sufficient to produce clinical parasitic gastroenteritis in five of nine control calves. The MSRT bolus reduced the mean egg output by more than 90% within 14 days after administration and prevented clinical parasitic gastroenteritis in the calves of Groups A and B. Owing to the persisting infection risk on Pasture A, the mean serum pepsinogen levels reached about 3000 mU tyrosine in the calves of Group A in September compared with approximately 2000 mU in Group B grazing the clean pasture. However, the differences in pasture contamination were not reflected in the mean bodyweight of the calves, which were 20 kg heavier at the end of the trial in both MSRT-treated groups compared with the control calves (P < 0.01). As there is a high probability that a moderate larval contamination is present on prealpine and alpine community pastures in summer, the metaphylactic use of an MSRT bolus in mid-July is likely to limit trichostrongylid infections within a subclinical range and thus provides sufficient protection of susceptible calves against parasitic gastroenteritis.

Topics: Animals; Cattle; Cattle Diseases; Delayed-Action Preparations; Feces; Female; Intestinal Diseases, Parasitic; Male; Morantel; Parasite Egg Count; Pepsinogens; Seasons; Switzerland; Trichostrongyloidiasis; Weather; Weight Gain

Topics: Abomasum; Animals; Blood Chemical Analysis; Feces; Female; Goat Diseases; Goats; Intestinal Diseases, Parasitic; Intestine, Small; Male; Morantel; Parasite Egg Count; Trichostrongyloidiasis

The efficacy of the Paratect Flex-Bolus for the control of parasitic gastroenteritis in calves was evaluated in a field experiment in the Swiss midland region. The bolus was administered to 9 first year grazing calves at 4 to 5 months of age before turnout on June 26 while 9 calves remained as untreated controls. Both groups were rotated between 8 paddocks that had been pregrazed by older cattle in spring. For a period of 12 weeks the faecal egg output of the treated calves was reduced significantly (p < 0.05) compared to the controls, whereas no significant differences were observed in the mean serum pepsinogen values of both groups. At the end of the experiment (November 14) the bolus-treated calves showed a 4 kg weight gain advantage over the controls which was not significant. The mild infection levels in both groups were probably due to the low pasture contamination with infective larvae throughout the season which most likely resulted from the late turnout of the calves. An outbreak of dictyocaulosis was observed in both groups in October and confirmed that the Paratect Flex-Bolus provides insufficient protection against this infection.

Topics: Animals; Cattle; Cattle Diseases; Delayed-Action Preparations; Dictyocaulus Infections; Intestinal Diseases, Parasitic; Male; Morantel; Strongylida Infections

An experiment was conducted in calves to investigate the efficacy of a morantel sustained release trilaminate bolus (MSRT) to control gastrointestinal parasitism and to assess the development of immunity during the use of MSRT. Two groups (M and U) of four calves each were infected three times a week with a mixed Ostertagia ostertagi and Cooperia oncophora infection for 12 weeks. Calves of Group M received an MSRT at the start of the experiment. Twenty weeks after the start of the experiment, all animals, including a previously uninfected control group (C), received a challenge with 100,000 Ostertagia and 100,000 Cooperia. After a further 4 weeks all calves were necropsied for worm counts. During the trial calves were weighed and faecal egg counts, larval differentiation and pepsinogen concentrations were determined. The results demonstrated the high level of efficacy of the MSRT in reducing the faecal egg output and preventing parasitic gastroenteritis under conditions of a continuous high rate of infection. Efficacy of treatment was higher for Cooperia than for Ostertagia. Post-mortem worm counts suggested a partially impaired immunity build-up in Group M, at least for Cooperia.

Topics: Animals; Cattle; Cattle Diseases; Delayed-Action Preparations; Feces; Immunity, Active; Intestinal Diseases, Parasitic; Morantel; Nematode Infections; Ostertagiasis; Parasite Egg Count; Pepsinogens; Random Allocation; Trichostrongyloidiasis; Weight Gain

A grazing experiment was performed in the Swiss midland region with 22 first-season calves which were grazed together from May to mid July when they were allocated to two equal groups, one receiving a morantel sustained-release trilaminate bolus (Paratect Flex) bolus, Pfizer, Zurich, Switzerland) and the other one remaining as an untreated control. Each group was moved to a clean pasture on 21 July. The larval contamination on the pasture with the control animals reached 4652 third stage larvae (L3) per kilogram of dry matter (L3 kg-1 DM) after 10 weeks. Parasitic gastroenteritis was observed in two calves of the control group in August, and mean serum pepsinogen levels exceeded 4000 mU tyrosine in this group in September. Eggs from Ostertagia sp. and Cooperia sp. that were excreted by the animals at the beginning of July and the end of August showed similar hatching rates of 94% and 99%, respectively. In the calves of the bolus group the egg output was reduced by 95% within 14 days of administration of the bolus. Larval contamination on the pasture of the bolus group was zero until the beginning of September when a slight increase occurred, reaching 793 L3 kg-1 DM in October. At the end of the trial the bolus-treated calves had a mean weight gain advantage of 18 kg (P < 0.05) compared with the controls. The results confirm that a second generation of larvae developed on pasture in August and September and caused parasitic gastroenteritis in first-year grazing calves in late summer. The relevance of the results for the prophylaxis of parasitic gastroenteritis in calves in mixed grazing systems with calves and older cattle is discussed.

Topics: Animals; Cattle; Cattle Diseases; Delayed-Action Preparations; Feces; Female; Intestinal Diseases, Parasitic; Larva; Male; Morantel; Parasite Egg Count; Pepsinogens; Seasons; Trichostrongyloidea; Trichostrongyloidiasis

An experiment was conducted in calves to investigate the effect of sustained release and pulse release anthelmintic intraruminal boli on the development of pathophysiological changes following daily infection with Ostertagia ostertagi and Cooperia oncophora for six weeks. After infection various pathophysiological changes were detected including increases in serum pepsinogen concentration, enteric plasma protein losses and in the catabolic rate of albumin. Such changes developed rapidly in the unprotected calves following patency after 17 days and persisted until the termination of the study. There were indications that the sustained anthelmintic release device was more efficacious than the pulse anthelmintic release device in reducing the worm burdens and early pathophysiological changes associated with infection. It was found at necropsy that the release of anthelmintic by the oxfendazole pulse release bolus had been delayed in several calves.

Topics: Animals; Anthelmintics; Benzimidazoles; Blood Proteins; Cattle; Cattle Diseases; Delayed-Action Preparations; Intestinal Diseases, Parasitic; Male; Morantel; Ostertagiasis; Parasite Egg Count; Pepsinogens; Serum Albumin; Trichostrongyloidiasis

The efficacy of a recently developed Morantel-Sustained-Release-Trilaminate-Bolus (Paratect Flex Bolus [PFB]-Pfizer Inc.) against gastrointestinal nematode infections in cattle was assessed by monitoring faecal egg counts (EpG), herbage larval counts, serum pepsinogen levels and liveweight gains in first season calves. In two field trials (1987 and 1988), a PFB-Bolus was administered to two different groups of animals (1987: 15 calves; 1988:13 calves) at turnout (29 May 1987; 26 May 1988), control groups were included. In 1988, 13 calves received for comparison an Oxfendazole-Release-Bolus (Systamex Intervall Bolus [OXF]-Coopers Inc.). All groups were grazed on adjacent but separately fenced pastures throughout the season, until housing (27 October 1987; 15 October 1988). When compared with controls, the PFB-groups showed significantly lower EpG values and consequently, lower herbage larval counts throughout the season in both trials. From day 30 after turnout, the PFB-group had significantly lower serum pepsinogen levels, which reflects the low degree of abomasal damage in these animals. When compared to controls, the PFB-treated animals showed significantly higher weight performances. The mean weight-gain benefit of PFB-treated animals was +12.5 kg (p less than 0.05) and +21.1 kg (p less than 0.005) in 1987 and 1988, resp. No difference occurred between PFB-treated and OXF-treated calves, the latter outperformed the control animals by +21.6 kg (p less than 0.005).

Topics: Animals; Cattle; Cattle Diseases; Delayed-Action Preparations; Intestinal Diseases, Parasitic; Morantel; Nematode Infections; Parasite Egg Count; Pyrimidines

A novel intraruminal bolus developed for the sustained delivery of the anthelmintic morantel tartrate was evaluated in the seasonal control of parasitic gastroenteritis in first season grazing calves. The morantel sustained release trilaminate is a trilaminate sheet consisting of a central lamina of a morantel tartrate/ethylene vinyl acetate matrix coated on both sides with a thin impermeable layer of ethylene vinyl acetate. A symmetrical pattern of circular perforations punched through the device controls the release of morantel. Administration of the trilaminate to calves significantly reduced their faecal egg output compared with untreated controls and thus reduced pasture larval contamination. Clinical parasitic gastroenteritis was prevented in the treated calves and there were significant reductions in their worm burdens compared with the untreated control calves both during and at the end of the grazing season. The control of parasitic gastroenteritis resulted in a significantly greater (P less than 0.0001) weight gain, of 45 kg, by the treated calves.

Topics: Animals; Cattle; Cattle Diseases; Delayed-Action Preparations; Feces; Gastroenteritis; Intestinal Diseases, Parasitic; Male; Morantel; Parasite Egg Count; Pyrimidines; Time Factors; Trichostrongyloidea; Trichostrongyloidiasis; Weight Gain

The efficacy of the first of a new generation of intraruminal devices for cattle, the morantel sustained release trilaminate, was assessed in two field trials. In each trial the animals were divided into a control group and a treated group. The device was administered to each calf before turn out in the spring and the reduction of gastrointestinal parasitism resulted in a substantial reduction in the level of pasture contamination with infective helminth larvae later in the season. Compared with the control calves the treated calves had a 94 per cent reduction of worm burdens acquired over the entire grazing season in the first trial, despite the controls being treated for clinical disease in September. In the second trial four anthelmintic treatments were administered to the control calves during the grazing season, but nevertheless a 64 per cent reduction of worm burdens in the treated group compared to the control group was recorded. The control of parasitic infection by the sustained-release devices resulted in mean weight gain advantages of 28.3 kg and 34.7 kg by the treated animals in the first and second trials respectively.

Topics: Animals; Cattle; Cattle Diseases; Delayed-Action Preparations; Female; Gastroenteritis; Intestinal Diseases, Parasitic; Male; Morantel; Parasite Egg Count; Pyrimidines; Weight Gain

The effectiveness of the morantel sustained release trilaminate (MSRT) in controlling gastrointestinal nematodes through a grazing season was evaluated using 60 yearling beef stocker calves randomly divided into 2 groups of 30 animals each. In April 1985, the calves comprising the treatment group each received an MSRT designed to release morantel tartrate continuously for 90 days while those of the control group remained unmedicated. All animals were weighed and samples of rectal feces were taken at 14-day intervals, beginning on Day 0, until trial termination (Day 168). At trial termination, 10 control and 10 treated calves were necropsied for recovery of gastrointestinal nematodes. Three sets of parasite-naïve tracer calves were utilized to evaluate the initial, interim and final levels of pasture contamination by nematode larvae. Overall, the use of the MSRT resulted in a 75.5% reduction (P less than 0.001) in output of nematode eggs from the principals, an 81.8% reduction (P less than 0.001) in numbers of gastrointestinal nematodes in principals (at trial termination), and a 96.9% reduction (P less than 0.05) of pasture larval nematode contamination (as indirectly indicated by parasite burdens in tracer calves). The mean weight advantage of treated calves was 16.6 kg per head (P less than 0.001).

Topics: Animals; Body Weight; Cattle; Cattle Diseases; Delayed-Action Preparations; Feces; Intestinal Diseases, Parasitic; Morantel; Nematoda; Nematode Infections; Parasite Egg Count; Pyrimidines; Random Allocation

Two early season suppressive anthelmintic programmes, ivermectin given three, eight and 13 weeks after turn out and a morantel sustained release bolus administered at turn out, were compared on a commercial farm. The morantel treated cattle grew significantly faster than the ivermectin treated group during the period of treatment, on average at 0.80 kg/day compared with 0.71 kg/day (P less than 0.01). In the second half of the grazing season (13 to 25 weeks after turn out) the ivermectin treated group grew faster than the morantel treated group although the difference was not statistically significant. Over the entire grazing season there was no significant difference in average growth rate between the morantel treated group which grew at 0.80 kg/day and the ivermectin treated group which grew at 0.77 kg/day. These results were related to pasture larval counts, faecal egg counts and plasma pepsinogen levels throughout the grazing period. It was concluded that the morantel sustained release bolus allowed growing cattle to reach their production potential during the period of treatment. However, its efficacy in maintaining production throughout the grazing season was reduced by the 90 day treatment period which failed to give the level of control of gastrointestinal nematode parasites achieved by the 105 day period of treatment in the ivermectin programme.

Topics: Animals; Cattle; Cattle Diseases; Delayed-Action Preparations; Intestinal Diseases, Parasitic; Ivermectin; Larva; Male; Morantel; Nematoda; Nematode Infections; Parasite Egg Count; Pepsinogens; Pyrimidines

The efficacy of a pulse-release oxfendazole bolus (OPRB) against gastrointestinal nematodes was evaluated under field conditions and compared with a sustained release morantel bolus (MSRB). Three groups of 10 calves were grazed from May to September on adjacent, similarly contaminated 3-acre paddocks. One group was dosed at turnout with the OPRB, the second group with the MSRB and the third group left as nontreated controls. Pasture larval counts peaked at greater than 60,000 larvae/kg dry weight of herbage in September on the control paddock, associated with a mean egg count of 1040 eggs/g faeces and clinical symptoms. A low rise in larval counts occurred on the MSRB plot, and also low helminth egg counts. On the OPRB plot, pasture larvae and faecal egg counts were recorded only intermittently; the September egg counts were only 3.5% of those of the controls; serum pepsinogen data showed a similar picture. At the end of the experiment, the OPRB calves had a mean weight advantage of 40 kg over the controls, and 12 kg over the MSRB group. Feed intakes were highest in the OPRB group in July and September.

Topics: Animals; Benzimidazoles; Cattle; Cattle Diseases; Delayed-Action Preparations; Feces; Intestinal Diseases, Parasitic; Male; Morantel; Nematoda; Nematode Infections; Parasite Egg Count; Weight Gain

Topics: Animals; Body Weight; Intestinal Diseases, Parasitic; Morantel; Niger; Parasite Egg Count; Pyrimidines; Sheep; Sheep Diseases; Vitamin A

The efficacy of using a bolus containing morantel in a sustained-release preparation for controlling naturally acquired gastrointestinal parasitic infections in weaned calves and yearling cattle was investigated during the 1982 grazing season at selected sites in the United States and Canada. According to a common trial design under various climatic and management conditions, 10 field trials were conducted with the bolus. At the time of spring turnout, a bolus was administered to each calf or yearling in the treated group. Then, treated and control cattle grazed separate but equal areas of divided pasture(s). The epidemiologic pattern of parasitic gastroenteritis in control animals and the effect of treatment on this pattern was determined in each trial. Safety and practicality of use of the bolus also were established. When compared with untreated cattle (control), those given the bolus deposited significantly (P less than 0.05) fewer worm eggs (89% reduction) during the first 90 days of the grazing season, as well as significantly fewer (P less than 0.05) worm eggs (84% reduction) during the entire grazing season. Consequently, during the second half of the grazing season, larval populations on treated pastures remained significantly (P less than 0.05) lower (66% reduction), compared with numbers of larvae found on control pastures. For pastures grazed by treated and control cattle at trial initiation, mean worm counts recovered from tracer calves were equal, indicating comparable pasture contamination at the beginning of the grazing season.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Body Weight; Canada; Cattle; Cattle Diseases; Delayed-Action Preparations; Feces; Helminthiasis; Helminthiasis, Animal; Helminths; Intestinal Diseases, Parasitic; Larva; Morantel; Parasite Egg Count; Pyrimidines; United States

Herbage intake was measured in two groups of 20 first-year grazing cattle. The animals in one group each received a morantel sustained release bolus at turnout to control nematode parasitism and the animals in the other group remained untreated. The latter group showed a mean peak faecal egg count of 655 eggs per gram (e.p.g.) in October associated with high serum pepsinogen concentration and clinical signs of ostertagiasis, compared with a peak of 119 e.p.g. in the treated group which remained in good health. In September the daily voluntary feed intake of the untreated animals was significantly depressed (94 g kg-1 body weight vs. 77 g kg-1 P less than 0.001), but no difference in digestive efficiency was recorded between the two groups. This difference in feed intake was associated with a 47 kg mean live weight advantage of the treated animals at housing.

Topics: Animals; Body Weight; Cattle; Cattle Diseases; Delayed-Action Preparations; Digestion; Eating; Intestinal Diseases, Parasitic; Male; Morantel; Ostertagia; Ostertagiasis; Pyrimidines; Seasons; Trichostrongyloidea; Trichostrongyloidiasis; Trichostrongylus

The efficacy of the morantel sustained release bolus (MSRB) in reducing gastrointestinal parasitism in first season grazing calves was evaluated during the summer--autumn grazing seasons of 1982 and 1983 in western Oregon. Each of 38 calves (1982) and 40 calves (1983) were randomly assigned to either control or treatment groups which were given MSRB on the day of turnout onto pasture. Mean worm burdens from tracer calves grazed with treated animals in 1982 and 1983 showed overall reductions of 86.4% (P greater than 0.05) and 84.3% (P less than 0.01), respectively, compared to tracers grazed with controls. Ostertagia ostertagi, Cooperia oncophora and Nematodirus helvetianus were the primary nematodes collected at necropsy. Twelve full-season 1982 tracer animals (6 treated and 6 control) indicated an 88.1% (P less than 0.05) overall reduction in mean worm burdens. Mean fecal worm egg per gram (EPG) counts of treated animals reflected a reduction of 69% (P less than 0.05) in 1982 and 90% (P less than 0.05) in 1983. Autumn inhibition of O. ostertagi was observed. In the 1982 trial the control animals showed a slight mean weight gain advantage over the treated group from Day 84 until Day 160 (trial termination) when the mean difference was 7.9 kg. The final mean weight gain advantage of treated animals in 1983 was 13.5 kg (P less than 0.05). These trials demonstrated that the MSRB was an effective anthelmintic for reducing gastrointestinal parasitism in grazing calves and for decreasing pasture larval contamination.

Topics: Animals; Body Weight; Cattle; Cattle Diseases; Delayed-Action Preparations; Female; Intestinal Diseases, Parasitic; Male; Morantel; Nematode Infections; Parasite Egg Count; Pyrimidines; Rain; Random Allocation; Seasons; Temperature

Three trials were conducted in southern England involving 120 autumn-born calves to evaluate the ability of an oxfendazole pulse-release intraruminal device (OPRB) to control parasitic gastroenteritis (PGE). Matched groups were set-stocked on adjacent paddocks. One group received an OPRB at turn-out; one was treated with an alternative chemoprophylactic programme; while the third acted as an untreated control. In each trial clinical PGE occurred in the latter group but not in OPRB or alternative strategy groups. The OPRB, the morantel sustained release bolus (MSRB) and fenbendazole administered at 3 and 6 weeks after turn-out gave similar weight-gain benefits when compared with untreated controls (P less than 0.01), but the growth rate of animals given regular levamisole treatments from July to housing was significantly poorer than the matching OPRB group (P less than 0.05) although better than controls. Faecal egg-output of OPRB calves was reduced by 97.0-99.9% compared with 95.5 and 58.9% for MSRB and fenbendazole treatments. Consequently, the late summer/autumn peaks in pasture larval counts were considerably reduced in all treatment groups other than the late-season levamisole strategy which reduced overall egg-output by only 37.6%. Serum pepsinogen and gastrin values confirmed a greater degree of abomasal disturbance in calves grazing on the more highly contaminated pastures. Incidental lungworm infections became clinically apparent in the control groups of two trials but not in any OPRB or alternative treatment group.

Topics: Animals; Anthelmintics; Benzimidazoles; Body Weight; Cattle; Cattle Diseases; Delayed-Action Preparations; Feces; Fenbendazole; Gastroenteritis; Intestinal Diseases, Parasitic; Levamisole; Morantel; Parasite Egg Count

The efficacy of the morantel sustained release bolus (MSRB) in controlling gastrointestinal parasitism in beef cattle was assessed during the 1982 spring-autumn grazing season. Forty-eight cows and their calves were allotted to three equal groups. One group (T-1) served as a nonmedicated control group. One MSRB was administered to each calf of the T-2 group, and to each cow and calf of the T-3 group at the beginning of the study. The efficacy of the bolus was assessed by comparison of weight gain performance and parasitological data (fecal worm egg counts, herbage larval counts, worm counts from tracer and principal trial calves, and plasma pepsinogen level determinations). Though not statistically significant, treated calves from Group T-2 had a numerical mean weight gain advantage of 2.6 kg, and those from Group T-3 of 4.7 kg, over control calves. Average daily gains (ADG) for the three groups of calves were 0.69, 0.72, and 0.73 kg, respectively. Untreated cows from Group T-2 and treated cows from Group T-3 outperformed the control cows by 12.3 and 7.5 kg, respectively. Fecal worm egg counts from both groups of treated calves were significantly (P less than 0.01) lower than counts from control calves during the entire 169-day trial; notably, egg counts were reduced by 99% 28 days after MSRB administration to both groups of calves. There were no significant differences in the number of eggs counted from the three groups of cows, probably because of the very low numbers of eggs encountered. Mean total worm burdens of principal calves (six per group) necropsied at trial termination indicated a 91% (P less than 0.01) reduction in Group T-2 and an 87% reduction (P less than 0.01) in Group T-3. Worm-free tracer calves were introduced onto pastures every 28 days to monitor availability of infective larvae. The mean number of worms recovered at necropsy from tracer calves that grazed with control cattle increased as the season progressed. However, the numbers of parasites recovered each month from mid-August through mid-October from tracers that grazed pastures with treated cattle were lower (P less than 0.05) than those levels displayed at trial initiation. In addition, the mean numbers of worms from treated group tracers were lower than from the controls for each necropsy period.(ABSTRACT TRUNCATED AT 400 WORDS)

Topics: Analysis of Variance; Animals; Body Weight; Cattle; Cattle Diseases; Delayed-Action Preparations; Feces; Female; Georgia; Intestinal Diseases, Parasitic; Male; Morantel; Parasite Egg Count; Pepsinogens; Pyrimidines; Random Allocation; Seasons

From Nov 22, 1983 through May 15, 1984, 36 crossbred steers were allotted into 3 treatment groups (12/group) and were grazed on separate 3.4-hectare pastures. On Nov 22, 1983, the steers were administered a single morantel sustained-release bolus (MSRB), orally (group 1), or a single dose of thiabendazole (TBZ; 66 mg/kg of body weight, orally; group 2), or were left untreated (group 3; controls). Animal weights, nematode egg counts in fecal specimens, and plasma pepsinogen concentrations were monitored monthly. At the termination of the study, 4 steers from each treatment group were slaughtered and necropsied and worm counts were determined. A set of parasite-free tracer calves (3/treatment group) were grazed with each treatment group for 1 month, beginning on Nov 22, 1983; a second set of tracer calves (3/group) were grazed with each treatment group for 1 month, beginning Apr 3, 1984. At the end of their respective grazing periods, tracer calves were held for 3 weeks and then were slaughtered and necropsied and their worm counts were determined. Mean nematode egg counts in fecal specimens of group 1 (MSRB treated) were significantly lower (P less than 0.05) than that of the TBZ-treated or nontreated steers. Differences in worm counts were not found between treatment groups. Differences in worm counts of tracer calves were not found among the 3 groups for November 1983 nor for April 1984. Steers treated with the MSRB had a higher mean weight gain (P less than 0.06) than did the control or TBZ-treated steers.

Topics: Animals; Cattle; Cattle Diseases; Delayed-Action Preparations; Gastrointestinal Diseases; Intestinal Diseases, Parasitic; Male; Mississippi; Morantel; Pyrimidines; Thiabendazole

Topics: Animals; Body Weight; Cattle; Cattle Diseases; Delayed-Action Preparations; Feces; Female; Gastroenteritis; Intestinal Diseases, Parasitic; Larva; Morantel; Ostertagiasis; Parasite Egg Count; Pyrimidines; Trichostrongyloidiasis

During the 6 years 1979-1984, the use of the morantel sustained release bolus (MSRB) was monitored in first year grazing calves. Twenty-four to 30 calves each year were allotted to two groups (controls and MSRB-treated) and turned out at the end of May on the same pasture divided into two equal areas. After housing in October, each group was kept in boxes and fed concentrates, whey and hay. The calves were weighed at monthly intervals until the first animals were sent to slaughter. No cases of clinical ostertagiasis Type I were observed in the control calves during the grazing seasons, but in one year (1983) clinical signs occurred 2 weeks after housing. The number of overwintering larvae was influenced by pasture contamination the previous season and climatic conditions during winter and spring. The fecal egg output of the control animals during the grazing season did not reflect the level of pasture contamination at turnout. The build-up of pasture larval contamination during the later part of the grazing season was influenced by the climatic conditions. The fecal egg output of the treated calves was low during the entire grazing season resulting in a significantly reduced pasture contamination. A significantly reduced live-weight gain in the control calves was demonstrated at housing in five of the six years. When heavily infected at housing, the performance of the control calves was still influenced negatively during the fattening period indoors.

Topics: Animals; Body Weight; Cattle; Cattle Diseases; Delayed-Action Preparations; Feces; Gastroenteritis; Intestinal Diseases, Parasitic; Male; Morantel; Parasite Egg Count; Pyrimidines; Rain; Seasons; Sweden; Temperature

The efficacy of the morantel sustained-release bolus (MSRB) in controlling gastrointestinal parasites in first-season grazing calves was evaluated on a dairy cattle farm in Belgium. The calves grazed a pasture which had been used by bolus-treated animals in the three previous years. The effect of bolus administration was determined with respect to live weight gain, faecal egg shedding, herbage larval counts, serum pepsinogen levels and ELISA antibody titres. In spite of an incomplete reduction of faecal egg shedding during the first months of the grazing season, bolus administration resulted in the prevention of parasitic gastro-enteritis in the calves. A weight gain advantage of 35,2 kg of the bolus-treated animals over the controls was noted already at two months after turnout. This weight gain advantage was maintained until housing. The usefulness of serum pepsinogen values and ELISA antibody titres as parameters in prevention experiments is stressed. Both serological parameters gave more information concerning infection level than did the faecal egg output and the herbage larval counts.

Topics: Animals; Antibody Formation; Belgium; Cattle; Cattle Diseases; Delayed-Action Preparations; Epidemiologic Methods; Intestinal Diseases, Parasitic; Morantel; Pyrimidines; Seasons; Trichostrongyloidiasis

The effectiveness of a morantel sustained-release bolus (MSRB) in controlling gastrointestinal nematode infections was determined in 70 Holstein heifer calves with no prior grazing experience. Calves were allotted to 2 treatment groups and were maintained in Florida during the grazing season on divided pastures of equal area. One MSRB was administered to each calf in 1 group at the time of turnout onto spring pasture, whereas calves in the other group remained as nonmedicated controls. By the end of the grazing season, treatment resulted in significantly (P less than 0.05) lower worm burdens and significantly improved weight gains. The MSRB-treated calves were able to reach breeding weight 2 to 4 weeks earlier than did nonmedicated calves.

Topics: Animals; Cattle; Cattle Diseases; Delayed-Action Preparations; Female; Florida; Intestinal Diseases, Parasitic; Morantel; Nematode Infections; Pyrimidines

The efficacy of a morantel sustained release bolus (MSRB) for control of gastrointestinal nematodes in yearling steers was evaluated over a 6-month grazing period commencing on 26 March 1982. Three groups of 15 steers were allotted to the following treatments: Group 1 -- one MSRB at start of trial; Group 2 -- one therapeutic dose of thiabendazole at start of trial; Group 3 -- untreated control. The treatment groups were grazed separately. Parasite egg counts (EPG), herbage larval counts, pepsinogen levels and weight gains were monitored. Every other month, sets of 2 parasite-free tracer calves were placed in the pasture grazed by each treatment group and allowed to graze for 3 weeks before being subsequently necropsied for worm counts. At the end of the trial, 6 animals from each group were also necropsied for worm counts. The MSRB treatment resulted in significantly lower egg counts, fewer infective larvae on pasture, lower pepsinogen levels and lower worm burdens in tracer calves than was the case for the untreated group, but generally the levels were not significantly different from those associated with the thiabendazole treatment. The mean weight gain for the MSRB treated steers showed a significant advantage (70.9 lb) over the untreated animals, but was not significantly different from those which received thiabendazole. Total worm counts at the end of the trial were not different from any treatment group.

Topics: Abomasum; Animals; Body Weight; Cattle; Cattle Diseases; Delayed-Action Preparations; Intestinal Diseases, Parasitic; Intestine, Large; Intestine, Small; Larva; Male; Morantel; Nematoda; Nematode Infections; Parasite Egg Count; Pepsinogens; Pyrimidines; Thiabendazole

Thirty-four heifers (24 Holstein, 8 Ayrshire, 2 Jersey) and 12 Holstein steer calves were grouped into 23 blocks of 2 animals each according to breed, sex, and body weight. Animals in each block were randomly assigned to control or treated groups. The treated group received an anthelmintic bolus containing morantel tartrate before they were permitted access to pasture. A 2.6 ha pasture was divided in half with a double fence; the resulting two pastures had separate feed and water troughs. Steer calves were slaughtered upon termination of the trial to ascertain gastrointestinal parasite burdens. Two worm-free tracer calves were placed on each pasture every 2 mo and slaughtered after 4 wk of grazing to determine parasite infectivity of pastures. Herbage samples were obtained monthly and analyzed for infective larvae. The trial was conducted for 141 d during the grazing season. Treatment resulted in 90% reduction in infective larvae on pasture, 74% reduction in fecal worm-eggs, 91% reduction in adult worm burdens, and a trend toward reduced worm burdens in tracer calves by 52%. An overall average daily gain of .68 and .88 kg was obtained for control and treated animals. Reproductive data for the heifers remaining in the herd from the trial showed that treatment resulted in 44 less days to first breeding.

Topics: Animals; Body Weight; Cattle; Cattle Diseases; Delayed-Action Preparations; Female; Intestinal Diseases, Parasitic; Larva; Male; Morantel; Nematoda; Nematode Infections; Parasite Egg Count; Pyrimidines; Seasons

Two experiments were done to evaluate the effectiveness of a slow-release, morantel tartrate, anthelmintic bolus for controlling parasitic gastroenteritis in replacement dairy heifers. In experiment 1, good control of nematode contamination of pasture was indicated by lower worm burdens in tracer calves that grazed with 15 heifers treated orally with a single bolus and by significantly decreased numbers of nematode eggs in the feces of the 15 treated heifers, as compared with numbers of eggs in the feces of 15 nontreated control calves. Significant differences in weight gain were not seen between treated and nontreated heifers, probably due to low amounts of larval exposure, the small number of heifers evaluated, and parasitic resistance in the heifers, which may have developed as a result of prestudy exposure to contaminated pasture. In experiment 2, done 1 year after the 1st experiment, using the same pastures that were used in experiment 1, young heifers were used. Many of the heifers were parasite naive at the beginning of the experiment (ie, nematode eggs were not found before the experiment). Treatment with the bolus was effective in controlling parasitic gastroenteritis in the heifers and in controlling nematode contamination of pasture. Compared with nontreated heifers, treated heifers had significantly higher cumulative weight gains, a significant decrease in plasma pepsinogen concentrations, and a significant decrease in worm egg excretion. The number of worms acquired by tracer calves that were grazed with treated heifers was significantly less than for tracer calves that were grazed with nontreated heifers.

Topics: Animals; Cattle; Cattle Diseases; Delayed-Action Preparations; Drug Evaluation; Female; Gastroenteritis; Intestinal Diseases, Parasitic; Morantel; Nematode Infections; Pyrimidines

Topics: Age Factors; Animals; Cattle; Cattle Diseases; Delayed-Action Preparations; Female; Gastroenteritis; Intestinal Diseases, Parasitic; Male; Morantel; Nematode Infections; Pyrimidines; Seasons; Strongyloidea

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 of the following species: Ostertagia ostertagi, Haemonchus contortus, Cooperia oncophora and Trichostrongylus colubriformis. The same dose rates also prevented establishment of Dictyocaulus viviparus infection but were ineffective against established infections of this parasite. In another two experiments the continuous release of morantel tartrate for at least 60 days (at rates between 0.65 and 1.11 mg/kg body weight per day) from a specially designed intraruminal sustained release bolus (secured at each end by a polyethylene impregnated semi-permeable membrane) was highly efficacious in both preventing the establishment of infections and removing established infections of the following species: O. ostertagi, T. axei, T. colubriformis and C. oncophora.

Topics: Animals; Cattle; Cattle Diseases; Delayed-Action Preparations; Dictyocaulus Infections; Drug Evaluation; Intestinal Diseases, Parasitic; Male; Morantel; Pyrimidines; Rumen; Trichostrongyloidiasis

The efficacy of the morantel sustained release bolus was evaluated in 20 first-season grazing calves and 92 cattle in two separate trials. All animals grazed contaminated pastures and were exposed at the time of spring turnout to a risk of infection from gastrointestinal nematodes. In the first study 45 bolus-treated and 47 nontreated control (second or third season) cattle grazed similar but separate communal pastures, while in the second study nine bolus-treated and 11 nontreated control cattle grazed together on a single pasture. Efficacy determinations were conducted by frequent observations throughout the grazing season on faecal worm egg output, serum pepsinogen levels and liveweight gain. In the older group of animals (Trial 1), small differences were recorded between treated and control animals in faecal worm egg output and levels of serum pepsinogen as monitored throughout the grazing season. A significant mean liveweight advantage of 20.27 kg (P less than 0.001) was observed in the bolus-treated group. However, unrecorded pregnancy could not be excluded with certainty as a factor responsible for weight differences. The use of the morantel sustained release bolus provided an adequate protection against parasitic gastroenteritis in the first season grazing calves (Trial 2) despite the fact that bolus-treated animals were co-mingled with control animals. Both the worm egg counts and serum pepsinogen values were lower in the bolus-treated group. The morantel sustained release bolus was well tolerated in both trials.

Topics: Animals; Body Weight; Cattle; Cattle Diseases; Delayed-Action Preparations; Dictyocaulus Infections; Drug Evaluation; Female; Intestinal Diseases, Parasitic; Morantel; Nematode Infections; Parasite Egg Count; Pepsinogens; Pyrimidines; Switzerland; Trichostrongyloidiasis

The efficacy of a morantel sustained release bolus was evaluated during the 1980 summer grazing season in 216 yearling, second-season cattle in nine trials in West Germany. In five trials individual farms were used, in which medicated and control groups could be grazed on adjacent pastures. In four additional trials medicated and control groups were maintained on separate farms where the sites and management practice were matched as far as possible. Faecal worm egg counts, herbage larval counts and weight gain were monitored at regular intervals throughout the season. The faecal output of gastrointestinal nematode eggs was reduced by 55.8 percent in the medicated animals during the period from May to early August, while worm egg counts were equal to that of the control animals during the later part of the season. Herbage larval counts were similar on pastures grazed by medicated and nonmedicated cattle. In the five trials where individual farms were used the average daily weight gains over the entire grazing period were 900 (+/- 222) g/animal/day in the medicated group compared with 826 (+/- 263) g/animal in the nonmedicated cattle, a non-significant advantage. No advantage for the treated over the control groups was detected in the additional 4 trials but this was attributed largely to the difficulty in obtaining comparable groups of animals in comparable grazing conditions in "matching" farms, leading to inter-farm variation.

Topics: Animals; Body Weight; Cattle; Cattle Diseases; Delayed-Action Preparations; Dictyocaulus Infections; Female; Intestinal Diseases, Parasitic; Male; Morantel; Nematode Infections; Parasite Egg Count; Plants; Pyrimidines; Seasons

The efficacy of the morantel sustained release bolus system for the control of parasitic gastroenteritis in calves was evaluated in the Netherlands. The effect of bolus administration to calves, either on May 1 at the beginning of the summer grazing season or on June 12 after the pasture was mown for silage, was determined in respect of liveweight gain, faecal worm egg output, serum pepsinogen values and worm burdens. In addition, pairs of tracer calves were turned out with each group every four weeks and sacrificed for worm counts in order to monitor pasture larval contamination throughout the grazing period. Compared with nontreated control calves, the worm egg outputs of the bolus-treated calves turned out (Nematodirus helvetianus), while the bolus-treated calves turned out on June 12 had a corresponding reduction of 95 and 100 percent. Over the grazing season the average weight gain of bolus-treated calves turned out on May 1 was 34 kg more than nontreated controls turned out at the same time. Difference in weight gain of the treated and control calves turned out late in the season was 10.5 kg in favour of the treated group. The postmortem worm counts were highest in the control calves turned out early and lowest in the bolus-treated calves turned out late. All tracer calves placed on the paddock grazed by control calves (turned out early) died from parasitic gastroenteritis from July onwards while those from the paddock grazed by the control calves (turned out late) died from parasitic gastroenteritis from September onwards. All the tracer calves placed on the paddocks grazed by bolus-treated calves survived until the intended slaughter date.

Topics: Animals; Body Weight; Cattle; Cattle Diseases; Delayed-Action Preparations; Drug Evaluation; Intestinal Diseases, Parasitic; Male; Morantel; Netherlands; Parasite Egg Count; Pepsinogens; Pyrimidines; Seasons; Trichostrongyloidiasis

The efficacy of the morantel sustained release bolus in controlling parasitic gastroenteritis in 153 first-season grazing cattle was assessed in three separate field trials conducted in Normandy, France. In each trial, comparisons were made on weight gain performance and parasitology data (faecal worm egg counts, herbage larval counts and- in two of the trials- worm counts from principal animals sacrificed at the end of the grazing season) when bolus treatment was given either at spring turnout or in mid-season in order to determine the optimum time for bolus administration. Cattle were allocated into three groups, each group maintained on a separate but equivalent paddock constructed from the division of a larger pasture. A morantel sustained release bolus was administered to one group of animals at the time of turnout and to a second group of animals in midsummer. The third group of animals in each trial remained nontreated. The effect of the treatment on the contamination of pasture, and parasite levels and weight gain of the principal trial animals was assessed. Similar results were observed in all three trials. Faecal worm egg counts were reduced during the first part of the grazing season in animals receiving the bolus at turnout compared with mid-season treated animals where egg counts followed a pattern similar to the controls until bolus treatment at which time counts abruptly dropped to a low level. Likewise, levels of infective larvae on pastures grazed by control and mid-season treated animals followed similar patterns, increasing to a high level in late summer, while larval levels on pastures grazed by early-season treated animals remained at low levels throughout most of the season. Serum pepsinogen levels, worm counts and weight gain reflected the results from faecal worm egg and herbage larval counts indicating that early-season treatment with the bolus provided the most efficient treatment time for controlling parasitic gastroenteritis throughout the grazing season. The overall mean weight gain advantage of the early-season bolus-treated animals over the controls was 37.2 kg (P less than 0.01) while the advantage of the mid-season treated animals over controls was 13.7 kg.

Topics: Animals; Body Weight; Cattle; Cattle Diseases; Delayed-Action Preparations; Drug Evaluation; France; Intestinal Diseases, Parasitic; Male; Morantel; Nematode Infections; Parasite Egg Count; Pepsinogens; Plants; Pyrimidines; Seasons

A economic and efficacy comparison in the control of parasitism in grazing cattle was conducted between conventional anthelmintic treatment applied according to various recommended regimes and an anthelmintic treatment delivered intraruminally at a sustained level from a specially designed bolus. The bolus used was the morantel sustained release bolus which has been designed to prevent the establishment of parasite infections so that, when administered at turnout to all cattle intended to graze the same pasture, parasitologically "safe" pastures could be produced and maintained for an entire grazing season. The various conventional anthelmintic treatment regimes used for the study were selected from the most commonly recommended and used systems of treatment found in commercial use throughout Europe. A total of 471 first-season grazing calves received the morantel sustained release bolus at spring turnout in 38 field trials conducted in Austria, Belgium, Denmark, France, West Germany, Ireland, the Netherlands, Norway, Sweden and the United Kingdom. In each trial, equal numbers of control and bolus-treated animals were maintained on separate halves of a divided pasture. In 25 of the 38 field trials, the control animals received tactical therapy with conventional anthelmintic only when exhibiting signs of parasitic gastroenteritis, while in the remaining 13 trials all animals in each control group received strategic anthelmintic treatment at specified intervals during the grazing season. Compared with control animals, significant reductions in faecal worm egg output of bolus-treated animals was recorded. Subsequent reductions in herbage larval contamination developed on pastures grazed by bolus-treated animals compared with control pastures so that, overall, the bolus-treated animals out-performed the control animals in all 38 trials by a mean of 16.3 kg (P less than 0.05). Labour and management costs (for animal treatment and handling) were substantially reduced in bolus-treated animals compared with animals receiving either tactical or strategic anthelmintic treatment.

Topics: Animals; Body Weight; Cattle; Cattle Diseases; Costs and Cost Analysis; Delayed-Action Preparations; Europe; Female; Gastroenteritis; Intestinal Diseases, Parasitic; Male; Morantel; Parasite Egg Count; Plants; Pyrimidines; Rumen; Seasons

The efficacy of the morantel sustained release bolus in controlling gastrointestinal helminth infection in second-season grazing cattle was investigated on a total of seven farms in southeast England. On each farm only animals which had grazing experience from the previous summer pasturing season were used. The animals on each farm were allotted into two equal groups and turned out onto divided pastures of equal size. All the cattle in one group received a bolus at turnout while the cattle in the other group remained as nontreated controls. Assessment of the efficacy of treatment was based on comparisons of faecal worm egg output, herbage larval counts, weight gain, and the incidence of clinical parasitic gastroenteritis during the grazing season. Use of the morantel sustained release bolus led to the cessation of worm egg excretion in bolus-treated cattle during the early part of the grazing season thereby preventing a subsequent buildup of infective larvae on pasture. Although the overall results from worm egg and herbage larval counts demonstrated little measurable effect of treatment, clinical parasitic gastroenteritis was prevented in two trials where control animals became clinically affected by parasitism. Overall, the bolus-treated animals outperformed the controls by a mean of 15.1 kg (P less than 0.001).

Topics: Animals; Body Weight; Cattle; Cattle Diseases; Delayed-Action Preparations; England; Female; Intestinal Diseases, Parasitic; Male; Morantel; Nematode Infections; Parasite Egg Count; Plants; Pyrimidines; Seasons

Topics: Animals; Cattle; Cattle Diseases; Delayed-Action Preparations; Intestinal Diseases, Parasitic; Morantel; Nematode Infections; Pyrimidines

Topics: Animals; Cattle; Cattle Diseases; Delayed-Action Preparations; Intestinal Diseases, Parasitic; Morantel; Nematode Infections; Parasite Egg Count; Pyrimidines

Topics: Animals; Anthelmintics; Bithionol; Cattle; Cattle Diseases; Drug Therapy, Combination; Ethiopia; Helminthiasis, Animal; Intestinal Diseases, Parasitic; Morantel; Niger; Tetramisole; Thiabendazole

Topics: Animals; Camelus; Chad; Intestinal Diseases, Parasitic; Morantel; Nematode Infections; Pyrimidines; Stomach Diseases