moxidectin and Weight-Gain

The objective of this study was to evaluate two different gastrointestinal nematode treatment regimens. Fecal egg counts (FECs), proportion of nematode genera, weight gain, body condition score and reproductive indices (estrous cyclicity, conception and pregnancy rates) were evaluated in yearling heifers after imposing two treatment regimens for gastrointestinal nematodes: T1 = 306 calves treated in May and November with 3.5 % doramectin (700 μg/kg) and August (Aug) with saline solution; and T2 = 307 calves treated in May with 3.5 % doramectin (700 μg/kg), in August with 1% moxidectin (200 μg/kg) and in November with 3.5 % doramectin (700 μg/kg). The animals were weighed, and feces were collected for conducting FECs and coproculture. There was imposing of three fixed-time artificial inseminations (TAIs), and estrous cyclic and pregnancy statuses were determined. Cooperia was the most frequent genus detected in both groups. Heifers of the T2, as compared to those in the T1 group, had fewer FECs in November (P ≤  0.05) and greater weight gain and average daily weight gain (P ≤  0.05) from August to November. There tended to be more heifers of the T2 than T1 group estrous cycling (P =  0.07) at the beginning of the breeding season as well as greater pregnancy rates (P =  0.03) and conception rates (P =  0.03) as a result of the second FTAI. The results indicate there is greater reproduction outcomes as a result of strategic control of gastrointestinal nematodes in yearling Nellore heifers using the T1 as compared with T2 treatment regimen.

Topics: Animals; Anthelmintics; Cattle; Cattle Diseases; Estrous Cycle; Feces; Female; Ivermectin; Macrolides; Nematode Infections; Parasite Egg Count; Pregnancy; Weight Gain

Two different deworming strategies based on the use of moxidectin, a broad spectrum endectocide with persistency against Ostertagia ostertagi, were evaluated in grazing dairy heifers. Eighty-four heifers unexposed to parasitic infection were randomly allocated to 3 different groups: untreated (Group 1), treated at 3 and 10 weeks after turnout with 0.5 mg/kg/body weight (BW) of topical moxidectin (Group 2), or treated at turnout and 10 weeks later with 0.5 mg/kg/BW of topical moxidectin (Group 3). The heifers were turned out on June 6 (Day 0) to a naturally contaminated pasture divided into 3 sections by an electrical fence. Each group of heifers was put on a different section of pasture. The trial ended when they were housed on October 29 (Day 143). The results of this experiment confirmed the beneficial effect of 2 strategic treatments with moxidectin pour-on under field conditions in Quebec. The parasitological parameters showed a statistical difference in terms of mean fecal egg counts between treated and control groups (ANOVA, P < or = 0.006). After turnout, pasture larval counts were consistently higher for Group 1 compared with counts for Group 2 or 3. All heifer groups gained weight during the trial period, but the weight gain profile of both treated groups was significantly higher than that of the untreated controls (ANOVA, P < 0.03). During the trial period, Group 2 and Group 3 gained 77.7 kg BW and 73.2 kg BW, respectively, while Group 1 gained only 57.9 kg BW, despite the fact that heifers of Group 1 received a greater quantity of supplementary feed while on pasture.

Topics: Abomasum; Analysis of Variance; Animals; Anti-Bacterial Agents; Antinematodal Agents; Cattle; Cattle Diseases; Feces; Female; Macrolides; Ostertagia; Ostertagiasis; Time Factors; Weight Gain

On the basis of Psoroptes ovis counts performed on day -7, 32 animals were randomly allocated to a control group of five animals or to four groups comprising six or seven animals which were treated, respectively, with pour-on ivermectin (IPO), injectable ivermectin (II), pour-on moxidectin (MPO) and injectable moxidectin (IM). Living mites were counted in skin scrapings on days 0, 7, 14, 28, 42 and 56 post-treatment (PT). Lesions were recorded on a standardized map on days 0 and 56 PT. Antibody kinetics were studied using ELISA on serially diluted sera. The antibody titres were expressed as the dilution giving the positive/negative cut-off. Until their treatment on day 28, the control animals remained parasitologically positive and their antibody titres increased. In treated groups, all living mite counts were negative on days 28 and 42 PT but some animals were still infected on days 7 and 14 PT. On day 56, living P. ovis were found in one animal of the IPO group. An equation of regression describing the antibody decrease was calculated with each individual data set. In most of the treated animals, the coefficient of determination R2, which describes the closeness of fit to the linear model, was above 0.9. The linear model could not be applied (low R2) to the antibody kinetics of four animals: the day 56 positive animal and its two neighbours in the IPO group and one animal from the MPO group. In the treated groups, the differences between the numbers of infected animals, the mean daily weight gains or the mean antibody titres were not statistically significant. Mean daily weight gains of the treated groups were higher than in control animals.

Topics: Animals; Anti-Bacterial Agents; Cattle; Cattle Diseases; Female; Insecticides; Ivermectin; Kinetics; Macrolides; Male; Mite Infestations; Skin; Weight Gain

Two similar studies were conducted in New Zealand to compare the therapeutic and persistent activity of doramectin injectable, moxidectin pour-on, ivermectin pour-on and oxfendazole oral drench when administered to nematode-infected cattle which were then grazed on common pastures. On day 0 (treatment day), 40 cattle were weighed, faecal sampled and allocated on the basis of day--3 faecal egg counts (FEC) to four treatment groups. Cattle were then treated with either doramectin by subcutaneous (s.c.) injection, moxidectin and ivermectin by topical application, or oxfendazole orally using label-recommended dosages. Oxfendazole treatment served primarily as a control to monitor reinfection without persistent activity. Faecal samples for nematode egg counts and coprocultures for larval differentiation were collected six times between day 0 and day 56 and all cattle were reweighed on day 56. Doramectin reduced pretreatment FEC by 99.1% in the first study and by 100% in the second study when assessed at 14 days posttreatment. Corresponding reductions for moxidectin were 80.8% and 85.2%, for ivermectin 86.0% and 80% and oxfendazole 78.3% and 100%, respectively. Posttreatment rise in FEC indicated that reinfection of moxidectin-treated animals occurred at the same time as oxfendazole controls in both trials. Posttreatment rise in FEC with ivermectin pour-on was similar to moxidectin and oxfendazole in one study, but in the other study ivermectin pour-on delayed the rise by 14-21 days. The rise in FEC for doramectin was delayed for 14-21 days in one study and at least 21 days in the other. The better parasite control provided by doramectin resulted in greater weight gains for cattle over the 56-day period as compared to moxidectin pour-on, ivermectin pour-on and oxfendazole in both trials. Gains of doramectin treated cattle were significantly (p < 0.05) greater than those of ivermectin and moxidectin groups in one trial and the oxfendazole group only in the other.

Topics: Administration, Oral; Animals; Anthelmintics; Anti-Bacterial Agents; Cattle; Cattle Diseases; Feces; Female; Gastrointestinal Diseases; Injections, Subcutaneous; Ivermectin; Macrolides; Male; Nematode Infections; New Zealand; Parasite Egg Count; Recurrence; Weight Gain

The efficacy of moxidectin, 'injectable' and 'pour on', against gastrointestinal nematodes was determined in cattle in two separate field trials (Trial I in 1990 and Trial II in 1991) with respectively 88 and 94 young grazing cattle of either sex. The efficacy was measured on the basis of the reduction of the egg output and of the evaluation of the results from larval differentiation. Animals in Group MI received 0.2 mg kg-1 body weight (b.w.) moxidectin injectable solution in Trial I on Day 0. Group CI was not given any medication on Day 0, but 0.2 mg kg-1 b.w. ivermectin injectable solution (Ivomec) was applied after 2 weeks to prevent clinical disease. In Trial II, animals in Group MP were treated with pour on moxidectin (0.5 mg kg-1 b.w.) on Day 0. Animals in Group CP serving as controls for Group MP during the first part of the trial received the same formulation at the same dose 2 weeks after treatment of Group MP. When the egg output was compared within treated groups, the egg count reduction was very similar post treatment (p.t.) with both formulations being 96.3% and 96.6% on Day 7 after the application of injectable moxidectin or pour on moxidectin, respectively, and 90.7% and 92.5% on Day 28 p.t. When egg counts of treated and control animals were compared (corrected for the e.p.g. values before treatment) the egg count reduction was 95.4% and 91.5% on Day 7 and 92.9% and 84.8% on Day 14 p.t. with either the injectable or pour on formulation. Pour on moxidectin seemed to be more effective against Ostertagia spp. than against Cooperia spp. Animals treated with injectable moxidectin gained significantly more body weight (4.2 kg per animal) than the controls from Day -7 to Day +14, while no significant difference in weight gain was achieved within 2 weeks after treatment with pour on moxidectin.

Topics: Administration, Topical; Animals; Anthelmintics; Anti-Bacterial Agents; Cattle; Cattle Diseases; Feces; Female; Injections; Intestinal Diseases, Parasitic; Macrolides; Male; Nematode Infections; Parasite Egg Count; Weight Gain

The aim of this work was to study the epidemiology and the harmful effect of gastrointestinal nematodes (GINs) on beef cattle in the piedmont forest and grassland region of northwestern Argentina, between March 2015 and March 2016. Sixty weaned female calves were divided into three groups: STG-calves treated systematically with 200 mcg/kg moxidectin every 40-50 days; LTG-calves treated as usually locally implemented, with 200 mcg/kg ivermectin on May 4 and August 5; and UTG-calves not receiving treatment. Moreover, a group of 20 untreated first-calving cows was monitored. Eggs per gram of faeces (epg) and faeces cultures were performed. Live weight gain (LWG) was recorded. Differences among groups were compared using analysis of variance and Tukey test. At the start of the experiment, mean epg was from moderate to high (595 ± 480); therefore, this group was treated in May. Mean UTG epg peaked (907 ± 754) in mid-winter, decreasing toward spring. LTG epg only decreased partially after treatment, showing 54.2% of ivermectin efficacy. Epg values of STG were always negligible values (95.8% of moxidectin efficacy). The dominant nematode genus was Cooperia (81.9%), followed by Haemonchus (15.5%). The effect of treatments was evident from middle autumn, with STG showing a significantly (p < 0.002) higher LWG than the other groups. Toward the end of the trial, LWG of STG and LTG increased by 27.2 and 8.2%, respectively, to those of UTG. This preliminary study showed a winter epg peak and a negative effect of GINs on LWG, even in moderately infected calves.

Topics: Animals; Antinematodal Agents; Argentina; Cattle; Cattle Diseases; Drug Evaluation, Preclinical; Feces; Female; Gastrointestinal Diseases; Gastrointestinal Tract; Haemonchus; Ivermectin; Macrolides; Nematoda; Ovum; Parasite Egg Count; Rhabditida Infections; Weight Gain

The objective was to determine the effect of supplementary feeding on the resilience and resistance of Criollo kids against natural gastrointestinal nematode (GIN) infections, when browsing native vegetation during the dry season in tropical Mexico. Thirty-three two-month-old Criollo kids, raised nematode free, were included at weaning in a 20-week trial. The kids were placed into four groups. Two groups of eight kids were offered 100g/day soybean and sorghum meal (26%:74% respectively fresh basis) (treated/supplemented (T-S) and infected/supplemented (I-S)). Two groups remained with no supplement for the duration of the trial (infected/non-supplemented (I-NS) (n=9) and treated/non-supplemented (T-NS) (n=8)). Kids in groups T-S and T-NS were drenched with 0.2mg of moxidectin/kg body weight orally (Cydectin, Fort Dodge) every 28 days. Groups I-S and I-NS were naturally infected with GIN. The animals browsed native vegetation for an average of 7h/day together with a herd of 120 naturally infected adult goats. Cumulative live weight gain (CLWG), packed cell volume (PCV), haemoglobin (Hb), total plasma protein and plasma albumin were recorded every 14 days as measurements of resilience. Resistance parameters (faecal egg counts (FEC) and peripheral eosinophil counts (PEC)) were also measured. Bulk faecal cultures were made for each group every 28 days. Every month a new pair of initially worm-free tracer kids assessed the infectivity of the vegetation browsed by the animals. Tracer kids and faecal cultures showed that kids faced low mixed infections (Haemonchus contortus, Trichostrongylus colubriformis and Oesophagostomum columbianum). Under conditions of scarce vegetation, such as those in the present study, supplemented groups (I-S and T-S) had higher growth rates compared to the non-supplemented groups independently of the control of GIN infection with anthelmintic (AH) treatment (P<0.001). Supplementary feeding did not affect FEC or PEC. In the absence of supplementation, lack of AH treatment may lead to outbreaks of clinical nematodosis. The supplementary feeding was economically feasible.

Topics: Animal Nutritional Physiological Phenomena; Animals; Antinematodal Agents; Diet; Dietary Supplements; Feces; Goat Diseases; Goats; Hematocrit; Hemoglobins; Host-Parasite Interactions; Intestinal Diseases, Parasitic; Leukocyte Count; Macrolides; Mexico; Nematoda; Parasite Egg Count; Seasons; Strongylida Infections; Weight Gain

The effectiveness, safety and production-enhancing benefit (improved weight gains) of moxidectin long-acting injection given subcutaneously in the ear at the rates of 0.75, 1.0 and 1.5mg/kg bw were evaluated in three studies under common protocol. The only adverse reaction to treatment was a mild (<2 tablespoons in volume), and for the most part transient (<28 days for the treatment rate of 1.0mg/kg bw) injection site swelling as noted in a minority of the animals (12.2% of the animals treated at the rate of 1.0mg/kg bw). Regardless of study site, post-treatment interval or dose rate, average daily gains were improved over control cattle by approximately 33%. Reductions in strongyle EPG counts relative to controls were > or = 90% for all dose rates of moxidectin for a post-treatment period of 42 days (Wisconsin), 84 days (Arkansas) and 140 days (Louisiana). In Arkansas and Louisiana, the majority (>80%) of post-treatment strongyle eggs, as determined by coproculture, were Cooperia spp. As determined by sequential necropsies, periods of continuous, post-treatment protection (> or = 90% efficacy in at least two out of three studies) for moxidectin long-acting injection given at the rate of 1.0 mg/kg bw were 90 days (adult Haemonchus spp.), 120 days (Dictyocaulus viviparus and adult Ostertagia and Oesophagostomum) and 150 days (Ostertagia spp. EL4).

Topics: Animals; Anthelmintics; Cattle; Cattle Diseases; Dose-Response Relationship, Drug; Feces; Helminthiasis, Animal; Helminths; Injections, Subcutaneous; Macrolides; Parasite Egg Count; Random Allocation; Strongylus; Treatment Outcome; Weight Gain

Trials were conducted in Arkansas, Idaho, Illinois and Wisconsin using a common protocol to evaluate effectiveness and safety of a long acting (LA), oil-based injectable formulation of moxidectin in beef cattle grazing spring and/or summer pastures. At each site, 150 cattle (steers and/or heifers) were blocked based on pretreatment fecal strongyle egg counts (EPG) and then randomly assigned to treatments within blocks. Presence of naturally acquired parasitic infections, confirmed by presence of parasite eggs in feces, was a prerequisite for study enrollment. Within each block of three animals, two received moxidectin LA injectable on day 0 at a dosing rate of 1.0 mg moxidectin/kg b.w. into the dorsal aspect of the proximal third of the ear, and one received a placebo control treatment. Cattle were weighed before treatment and on day 55 or 56 (55/56) after treatment. Fecal samples were also collected from 10 randomly selected blocks of animals at each site on days 14, 28 and 55/56 for EPG quantification. Average daily gain (ADG) was computed over the posttreatment period. Data pertaining to ADG and EPG were combined across sites and analyzed by mixed model analysis of variance to assess the fixed effect of treatment and random effects of site, block within site and the treatment by site interaction. Compared to placebo-treated controls, the geometric means of fecal EPG counts from cattle treated with moxidectin LA injectable were reduced 99.8% 14 days after treatment, 99.1% 28 days after treatment and 96.7% 55/56 days after treatment. Rate of weight gain by cattle treated with moxidectin LA injectable was 0.59 kg/day, or 23% (0.11 kg/day) more than placebo-treated controls (P<0.05). None of the cattle treated with moxidectin LA injectable exhibited signs of macrocyclic lactone toxicosis. Summarized across all study sites, proportions of cattle that received concurrent therapeutic treatments were similar among treatment groups. Study results demonstrate that moxidectin cattle LA injectable administered at a dosing rate of 1.0 mg moxidectin/kg b.w. to grazing beef cattle was effective and safe.

Topics: Analysis of Variance; Animals; Antinematodal Agents; Arkansas; Cattle; Cattle Diseases; Delayed-Action Preparations; Feces; Female; Idaho; Illinois; Injections, Subcutaneous; Macrolides; Male; Parasite Egg Count; Random Allocation; Safety; Strongylida Infections; Treatment Outcome; Weight Gain; Wisconsin

Psoroptes ovis counts, extent of lesions (clinical index: ClinI), daily weight gains (DWGs) and anti-P. cuniculi antibody titres in ELISA were recorded during seven therapeutic field trials. Relationship between these different data were studied. The differences between the mean DWG of treated and untreated control animals of the different trials ranged from 39 to 1206 g/day. Data were pooled for statistical analysis and the influence of trial conditions (management of the herd, farm, treatment) was extracted from each individual data by subtracting, from the DWG of each animal, the mean DWG of its trial. Such data were called daily weight gain over the trial mean (DWG/TM). Multiple regression of DWG/TM, calculated over the period between the clinical examinations in control animals (n = 40), on clinical indices and sex demonstrated a significant DWG/TM reduction per percentage of affected body surface according to the following equation: DWG/TM (in g/day)= 135-22 ClinI(0)-13 ClinI(28/35)-70 (if male) (R2 adjusted = 0.39), where ClinI(0) and ClinI(28/35) are the clinical indices recorded respectively at the beginning (day 0) and at the end (day 28 or 35) of the experimental period during which the animals were left untreated. A nonsignificant relationship (R2 adjusted = 0.07) was found between the antibody titres on day 28 or 35 and the individual DWG/TM This would suggest that serology could be used to estimate the prevalence of the disease on a local or national basis but not to calculate its economic impact.

Topics: Animals; Anti-Bacterial Agents; Antibodies; Body Weight; Cattle; Cattle Diseases; Enzyme-Linked Immunosorbent Assay; Female; Insecticides; Ivermectin; Macrolides; Male; Mite Infestations; Mites; Regression Analysis; Weight Gain

During the winter 1991-92, 42 reindeer hinds of the Kaamanen Experimental Reindeer Herd in Finnish Lapland, naturally infected with various parasites, were allocated to 3 groups. One group was an untreated control group and the other 2 groups received either moxidectin or ivermectin at a dose of 200 micrograms kg-1 subcutaneously. The efficacy of treatment was followed with monthly faecal examinations for nematode eggs and counting of warbles, Hypoderma tarandi larvae, and throat bots, Cephenemyia trompe larvae, from live animals in spring. The efficacy of moxidectin against warbles (92.8%) and throat bots (70.8%) did not match that of ivermectin, which was 100% against both species. Both moxidectin and ivermectin were effective against gastrointestinal trichostrongylid egg production over the December to May trial period indicating good efficacy against adult and inhibited trichostrongylids. Only non-significant differences were seen in weight development and calf birth weights between the groups. Because of its only moderate insecticidal efficacy, moxidectin cannot be recommended as an endectocide in reindeer.

Topics: Animals; Animals, Newborn; Anthelmintics; Anti-Bacterial Agents; Birth Weight; Capillaria; Feces; Female; Ivermectin; Macrolides; Parasite Egg Count; Parasitic Diseases, Animal; Pregnancy; Reindeer; Trichostrongyloidea; Weight Gain

Field efficacy of injectable moxidectin was evaluated in sheep naturally infested with both Psoroptes ovis and Sarcoptes scabiei var. ovis mange. Three groups of 15 ewes were selected from the flock based on parasitological and clinical status. Group 1 remained as untreated controls; Group 2 animals received a subcutaneous injection of moxidectin at 0.2 mg kg-1 body weight on Day 1; Group 3 animals received 0.2 mg kg-1 moxidectin twice on Day 1 and Day 7. Efficacy was assessed by taking skin scrapings from each animal on Days -4, 0, 7, 14, 28 and 35 post-treatment and counting viable mite stages and species. In both treated groups the signs of itching disappeared within 7 days post-treatment. Rapid clinical improvement was associated with reduction in numbers of mites compared with initial score which was over 90%. However, in skin scrapings on Day 7 post-treatment several live mites of both species were present. The second injection of moxidectin removed all living mites, and skin scrapings from Group 3 animals were negative for all mites on Days 14, 28 and 35. The weight gain on average was 2.0 kg in Group 2 and 2.7 kg in Group 3 during the 35 days of trial. Untreated control animals lost on average 3.1 kg from their weight at the start of the trial. All untreated animals remained positive and suffered from intensive scratching, anorexia and moist, active skin lesions. They were given an emergency moxidectin treatment on Days 35 and 42, each animal receiving 0.2 mg kg-1 body weight, subcutaneously.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Anti-Bacterial Agents; Cattle; Drug Evaluation; Insecticides; Macrolides; Mite Infestations; Scabies; Sheep; Sheep Diseases; Weight Gain

The efficacy of moxidectin against gastrointestinal nematode infections was studied in 30 Fleischschaf x Rasa Aragonesa male lambs aged 3 months at the beginning of the experiment. The lambs were distributed in three groups of 10 animals each and experimentally infected with a mixture of an equal number of infective (L3) larvae from each of the following species: Haemonchus contortus (2000), Ostertagia circumcincta (2000), Trichostrongylus colubriformis (2000) and Trichostrongylus vitrinus (2000). Two groups of lambs were drenched with 0.2 mg moxidectin per kg body weight at 6 (Group B) and 21 (Group C) days post challenge while the third group of animals (Group A) remained untreated. The efficacy of the treatment based on worm counts 4 weeks post infection was of 100% against 4th stage larvae of all species and 100%, 99.98%, 100% and 100% against adults of H. contortus, O. circumcincta, T. colubriformis and T. vitrinus, respectively. Significant differences were found in daily weight gain between treated (Group B+C, 157.9 g day-1) and untreated lambs (Group A, 116 g day-1). No differences in feeding behaviour or health condition between treated and untreated lambs were observed.

Topics: Abomasum; Administration, Oral; Animals; Anthelmintics; Anti-Bacterial Agents; Feces; Intestinal Diseases, Parasitic; Intestine, Small; Macrolides; Male; Nematode Infections; Parasite Egg Count; Sheep; Sheep Diseases; Weight Gain