morantel and Body-Weight

On the basis of the hypothesis that the peak numbers of infective nematode third-stage larvae (L3) on herbage in winter months results from fall contamination of pastures, 2 methods to reduce fall contamination were tested. In trial 1, morantal sustained-release boluses were administered to 15 fall-calving cows on Sept 7, 1982. Fifteen untreated cows (controls) were placed on separate pastures. Numbers of L3 on herbage during the winter and spring were assessed by use of worm-free tracer calves. In trial 2, 19 cattle due to calve in the fall were administered 200 micrograms of invermectin/kg of body weight, SC, on Sept 2, 1983. Also, 17 cattle similarly were given a placebo injection and served as control animals. Treated cattle were placed on the pasture used by control cattle in trial 1 and control cattle on the pasture used by treated cattle in trial 1. Worm-free tracer calves were again used to assess numbers of L3 on herbage. In trial 1, tracer calves grazing the control animal pasture from January 14 to 28 acquired 37 times as many nematodes as did those grazing the treated animal pasture. In trial 2, the greatest difference observed was a 10-fold increase of nematodes in calves grazing control animal pastures, compared with worm numbers in tracer calves grazing the treated animal pasture.

Topics: Animals; Body Weight; Cattle; Cattle Diseases; Delayed-Action Preparations; Feces; Female; Gastroenteritis; Ivermectin; Larva; Male; Morantel; Nematoda; Parasite Egg Count; Pregnancy; Seasons

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

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 groups of 21 mixed-breed heifers were wintered on separate permanent pastures. Each heifer from one group was administered a sustained-release morantel bolus on October 7 (day 0), and the other group remained as untreated controls. Body weights were determined and fecal samples were taken at 28-day intervals. At the onset of the trail and at every 56 days, 6 heifers were removed from each group for slaughter to determine the developmental stages and the number of gastrointestinal nematodes. In addition, 3 tracer calves that were free of gastrointestinal nematodes were released on each pasture for 28 days at the beginning of the trail and after the last experimental-group calves had been removed. The 6 calves slaughtered on day 0 of the trail had a mean of 5,544 gastrointestinal nematodes. Tracer calves released on day 0 and removed on day 28 of the trial acquired 31,143 and 30,530 gastrointestinal nematodes from the pastures containing the treated and control heifers, respectively. Throughout the trial, the number of nematodes in the control calves increased at each sampling date (mean, 126,168 worms), whereas the mean number of worms in the treated heifers was 45,458. Tracer calves placed in the pastures after the 168-day trail acquired significantly more worms (9,632 vs 2,899; P less than 0.05) from grazing the pastures with control heifers than from grazing the pastures with treated heifers. Counts of eggs per gram of feces were significantly different (P less than 0.01) between the 2 groups from day 28 through day 112.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Body Weight; Cattle; Cattle Diseases; Delayed-Action Preparations; Feces; Female; Morantel; Nematode Infections; Parasite Egg Count; Pyrimidines; Seasons; United States

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

Topics: Animals; Body Weight; Morantel; Niger; Pyrimidines; Sheep; 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

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

Nematodiasis and its subsequent effect on production in Hereford weaner steers in western Victoria was studied during 1983 and 1984. In the first summer, steers were allocated to 2 replicates of 6 treatments--No treatment (Nil); Morantel slow release bolus in March (M1); Morantel bolus in March and June (M2); pour-on levamisole in January, May and July (R3); albendazole in January and July (V2) and albendazole in January, May and July, (V3). In 1984, treatment M2 was discontinued to provide extra replicates for Nil and M1. The replicate paddocks were 5 ha and were stocked with 7 and 8 steers in 1983 and 1984, respectively. Nematode egg counts in faeces, were generally less than 50 epg, indicating low numbers of adult nematodes. Faecal egg counts were highest in autumn and declined during the year. There was a significant (P = 0.02) effect of treatment on mean faecal egg count. Mean egg counts for treatment groups Nil and M1 were 16 and 10 epg above the overall mean (47 epg); those of the other treatments were 6 to 12 epg below the mean. There were no significant (P = 0.8) differences between treatments in the numbers of nematode larvae on pasture, during the experiment. At the end of both years of the experiment most nematodes (92%) were early fourth stage larvae of O. ostertagi. There were no consistent differences in nematode counts between treatments. There were no significant (P = 0.33) differences between treatments in bodyweights at any time during the experiment.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Albendazole; Animals; Anthelmintics; Australia; Benzimidazoles; Body Weight; Cattle; Cattle Diseases; Feces; Levamisole; Male; Morantel; Nematode Infections; Ostertagiasis; Parasite Egg Count; Seasons

Three groups of calves, previously grazed on permanent pastures contaminated with bovine trichostrongyle (Ostertagia and Cooperia species) infective larvae, were housed from October to May. During the grazing season one group had received fenbendazole at fortnightly intervals to suppress trichostrongyle infections, one received a morantel sustained release bolus before grazing to limit trichostrongyle contamination of the pasture, and the control group was only medicated when heavy infections caused clinical type 1 ostertagiasis. Digestibility of the whole diet was poorer in the control cattle, particularly for dry matter, crude protein and energy fractions. Balance studies conducted throughout the winter housed period showed that both increased faecal and urinary nitrogen outputs in the control animals contributed to a significantly reduced overall nitrogen retention. The effects were most apparent during clinical type 2 ostertagiasis, which occurred in March in the control group.

Topics: Aging; Animal Feed; Animals; Benzimidazoles; Body Weight; Cattle; Cattle Diseases; Delayed-Action Preparations; Digestion; Fenbendazole; Male; Morantel; Nitrogen; Poaceae; Pyrimidines; Trichostrongyloidiasis; Trichostrongylosis

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

In an experiment carried out in 1981 and 1982, the effect of the use of a morantel sustained release bolus (Paratect bolus) on the weight gain and a number of parasitological parameters of cattle was studied. In the first year 42 calves were divided into 3 equal groups, one group was kept outside and treated with a bolus (B), the second group was kept outside and was not treated (C), while the third group remained indoors (I). Groups B and C were grazed separately on contaminated pasture. During the first months Group B had a negligible egg output. The egg output in the controls was much higher and in mid-August they had to be treated for parasitic gastroenteritis. At the end of the grazing season the advantage in weight gain of Group B was 20 kg compared with the controls. During the housing period the growth in the 3 groups was not significantly different. At the start of the second grazing season half the animals of Groups B, C and I received a bolus (Groups BB, CB and IB). The other half remained untreated (BC, CC and IC). The animals treated with a bolus in 1982 gained significantly more weight (64 g/day) than untreated animals. Heifers turned out for the first time (IB and IC) showed much less weight gain than heifers in their second grazing season. The heifers which had previously grazed in 1981 had a very low egg output compared with Groups IB and IC, although the level of egg output of the latter was also not very high (max, almost 40 (eggs per gram (EPG)). In faecal cultures of heifers of Group BC, CB and CC, no Cooperia oncophora-larvae were seen from May onwards, indicating a strong immunity against this species. In Group BB very low numbers of C. oncophora-larvae were observed. In Groups IB and IC, C. oncophora was present during the whole season. At the end of the first season the level of herbage infestation on the control pastures was much higher. In 1982 only slight differences in level of infestation between the pastures were observed. At the start of the season in 1982 serum pepsinogen levels were much higher in the groups which grazed in 1981, compared with the indoor-fed groups. Groups BC and CC had significantly higher levels than Groups BB and CB and all 4 groups always had higher levels than Groups IB and IC.(ABSTRACT TRUNCATED AT 400 WORDS)

Topics: Animals; Antibodies; Body Weight; Cattle; Delayed-Action Preparations; Feces; Female; Larva; Morantel; Parasite Egg Count; Pepsinogens; Poaceae; Pyrimidines; Seasons; Species Specificity; Trichostrongyloidea; Trichuris

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

The morantel sustained release bolus was administered at turnout to first-season grazing calves in order to assess its efficacy in the seasonal control of infection by nematode parasites in Ireland. The pastures grazed by control calves showed a marked increase in gastrointestinal trichostrongylid infective larvae by September, while numbers of infective larvae on pasture grazed by bolus-treated calves remained at a low level throughout the grazing season. In consequence, the controls showed significantly higher worm egg counts in late season and significantly higher worm burdens (mainly Ostertagia spp) at necropsy carried out in November on representative number of principal animals selected from each group. These reduced worm burdens were attributed to the suppression of egg output during the early part of the season as a result of treatment with the morantel sustained release bolus at turnout in the spring. Pasture contamination with Dictyocaulus viviparus larvae was present on all treatment pastures. The bolus-treated calves however were subjected to an increase in D. viviparus infection which occurred on their pasture in late season after the active life of the bolus had expired. It was concluded that bolus treatment delayed (rather than prevented) the buildup of D. viviparus infection on the pasture by 60-90 days.

Topics: Animals; Body Weight; Cattle; Cattle Diseases; Delayed-Action Preparations; Dictyocaulus Infections; Drug Evaluation; Ireland; Male; Morantel; Ostertagiasis; Parasite Egg Count; Pyrimidines; Seasons; 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 in controlling gastrointestinal and lungworm parasites when used in first-season grazing animals which followed older animals onto spring pasture (deprime system) was assessed in three trials conducted in Normandy, France. In each trial first-season grazing calves were equally allocated onto two separate but equivalent paddocks where they remained throughout the grazing season. A morantel sustained release bolus was administered to one group of animals at turnout, the other group remained as controls. The effect of the treatment on contamination of pasture (herbage larval counts and tracer worm counts), on faecal worm egg and lungworm larval counts, and on weight gain performance of the principal animals was assessed. In all three trials, worm egg output in the bolus-treated animals was substantially lower throughout the season compared with the control animals. Worm burdens of tracer calves grazing pastures of the treated cattle were also reduced compared with tracer calves grazing control pastures. Clinical parasitic gastroenteritis occurred in the control animals but not in the bolus-treated animals in one trial. Overall the bolus-treated animals outperformed the controls by a mean weight gain advantage of 10.5 kg (P less than 0.01).

Topics: Animal Husbandry; Animals; Body Weight; Cattle; Cattle Diseases; Delayed-Action Preparations; Dictyocaulus Infections; Drug Evaluation; Female; France; Male; Morantel; Nematode Infections; Parasite Egg Count; Pepsinogens; Plants; Pyrimidines; Seasons; Trichostrongyloidiasis

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 a morantel sustained release bolus to control gastrointestinal parasitism during two consecutive grazing seasons was assessed in replacement dairy heifers raised under field conditions in Austria. Thirty calves were randomly allotted into two equal groups and maintained throughout the 1979 summer pasturing season on adjacent pastures of equal size with identical grazing history. Twenty-four of the thirty calves used in 1979 were monitored throughout 1980, each animal remained in the same treatment group as the previous year and grazed the same pastures as the previous year. In both 1979 and 1980 the bolus was administered to each animal in the treated group one week before turnout onto spring pastures, while the control animals received no anthelmintic treatment during either year. The efficacy of the bolus was assessed by comparison of faecal worm egg counts, herbage larval counts, worm counts from tracer and principal trial animals, weight gains and by the incidence of clinical disease found in both tracer and trial animals throughout the grazing season. Milk production was also monitored for all animals in both treatment groups during the first lactation. The system of treatment used in the present study with the morantel sustained release bolus was highly effective in preventing a significant buildup of infective larvae on pasture to the end of the grazing season in both years. In 1979 worm counts of tracer calves grazed on the treated pastures in mid-August were similar to those recorded at the beginning of the season, while worm counts in the control tracers were five times the total found at the beginning of the season. In 1979 the bolus-treated calves outperformed the control group by 34.8 kg (P less than 0.001) over the 168-day grazing period. These results demonstrated that administration of the bolus to calves at the time of turnout onto spring pastures was most effective both in controlling parasites within the cattle themselves and in reducing the level of parasite contamination. During the second grazing season (1980) no beneficial effect in weight gain was observed due to the second bolus treatment. Weight gains realized during the first year, however, largely remained through the second year and the bolus-treated heifers reached breeding weight on average 19 days earlier. No difference in milk yield was observed between the treated and control animals during thier first year of lactation.

Topics: Animals; Austria; Body Weight; Cattle; Cattle Diseases; Delayed-Action Preparations; Drug Evaluation; Female; Morantel; Parasite Egg Count; Pyrimidines; 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

During two consecutive grazing seasons, the strategic use of the morantel sustained release bolus (MSRB) was monitored each year in first season grazing calves (maintained both years on the same pasture). The object of the study was to determine the effects of bolus treatment in young calves during successive years on the level of pasture larval contamination available at the beginning of the second year, and on the pattern of pasture recontamination that occurred during the second year. The level of worm burdens acquired in the trial animals at the end of the grazing season was determined both years. Tracer worm counts were determined during the first year of the study, while faecal worm egg counts, herbage larval counts and weight gain were monitored both years. During the first year (1979) the selected pasture was equally divided into three separate paddocks. Two paddocks were grazed by control calves, while each animal grazing the third paddock received a bolus at the time of turnout. During the second year (1980) three groups of calves were used. One group was treated with the bolus and grazed the same paddock as calves treated with the bolus the previous year. The second group was treated with the bolus and grazed the control paddock from the previous year, while the third group of calves remained nontreated and grazed the remaining paddock grazed by control calves from the previous year. As a result of the bolus treatment during the first year, the number of overwintering nematode larvae recovered the following spring was considerably lower than the number recorded on the paddock grazed previously by control animals. Worm counts and efficacy calculations demonstrated that worm burdens accumulated during the season were considerably lower in the bolus treated cattle during the second year than during the first. These parasitological differences were reflected in the weight gain comparisons between the treated and control cattle. Although significantly improved weight gains were recorded for both groups of treated cattle compared with the control cattle during the second year, the treated cattle grazing the treated paddock had a greater improvement than the treated cattle grazing the control paddock from the previous year.

Topics: Animals; Body Weight; Cattle; Cattle Diseases; Delayed-Action Preparations; Drug Evaluation; Male; Morantel; Parasite Egg Count; Plants; Pyrimidines; Seasons; Sweden; Trichostrongyloidea; Trichostrongyloidiasis

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

A field trial was conducted to determine (1) the effectiveness of an anthelmintic program using morantel tartrate (MT) to control subclinical gastrointestinal parasitism among cattle on pasture and (2) the effects of the program on the performance of cattle. Two Hereford herds, each on a separate pasture with forage of comparable quality and quantity, were used. A stocking rate of .62 ha/cow-calf was maintained in both pastures. One herd consisted of 124 cows and 122 calves and served as a non-mediated control group. The second herd consisted of 126 cows and 124 calves. Cows and calves from the latter group were treated with a bolus formulation of MT at a dosage of 10 mg/kg body weight at the beginning of the trial and again 55 d later. Calves were treated again 42 d after the second treatment. Cattle were weighed individually each month and rectal fecal samples for nematode egg counts were obtained from 36 cows and 36 calves from each group at that time. These donor cattle were selected at random at the time of the first weighing; fecal samples were then obtained from the same animals throughout the study. Eggs of the Cooperia-Ostertagia-Trichostrongylus complex predominated in all fecal samplings. There was no difference in the number of nematode eggs from the two groups of cows. However, the medicated cows gained significantly more weight than the controls and had an average weight gain advantage of 28.8 kg. The medicated calves had significantly lower average egg counts and made higher weight gains than the unmedicated calves. The medicated calves had an average weight gain advantage over the control group of 11.1 kg.

Topics: Animals; Body Weight; Cattle; Cattle Diseases; Feces; Female; Morantel; Nematoda; Nematode Infections; Parasite Egg Count; Pyrimidines; Seasons

The effect of the morantel sustained release bolus was studied in a group of first-season grazing calves kept together with an untreated control group. The groups were kept together to eliminate the uncontrollable influence of uneven nutritional conditions on weight gain when groups are kept on separate pastures. The calves were given one bolus just before turnout and a second three months later. In the treated calves, the number of nematode eggs in the faeces was kept on a low level during most of the grazing season, except for a slight rise in the egg counts after two months of pasture, before the second bolus was given. At the end of the 5 months' grazing period the live weight gain of the treated calves was 29.1 kg greater than that of the control calves (p less than 0.01), and the treated animals were in a far better condition than the untreated. The experiment showed that the MSRB prevented a significant weight loss due to gastrointestinal nematodes.

Topics: Animal Feed; Animals; Body Weight; Cattle; Cattle Diseases; Delayed-Action Preparations; Male; Morantel; Nematode Infections; Parasite Egg Count; Pyrimidines

Topics: Animal Feed; Animals; Body Weight; Cattle; Cattle Diseases; Delayed-Action Preparations; Male; Morantel; Nematoda; Nematode Infections; Parasite Egg Count; Pyrimidines

Forty heifer calves, 27 yearling heifers, and 64 yearling steers with naturally occurring infections of nematode parasites were treated with levamisole HCl or morantel tartrate or were not treated. Although heifer calves had much larger worm egg counts before treatment than yearling heifers, necropsies showed a smaller average number of nematodes in the calves. Both anthelmintics significantly reduced the egg counts. At the end of the experiments, 98 to 240 days after treatments, there was no significant difference among groups of cattle in respect to necropsy worm counts. An advantage of 5% in rate of gain in body weight was shown in each experiment or phase of an experiment in favor of the treated groups of cattle. Overall, an advantage of 6% in feed efficiency was calculated for the treated groups of cattle.

Topics: Animal Feed; Animals; Anthelmintics; Body Weight; Cattle; Cattle Diseases; Feces; Female; Georgia; Helminthiasis; Helminthiasis, Animal; Levamisole; Male; Morantel; Parasite Egg Count