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1.
A new synthetic pyrethroid, cyhalothrin, has been evaluated as both a sheep dip and a jetting fluid for the control of body lice ( Damalinia ovis ), face lice ( Linognathus ovillus ), foot lice (Linognathus pedalis) and the sheep ked (Melophagus ovinus). A dip wash concentration of 1.25 ppm cyhalothrin eradicated D. ovis from sheep. A jetting fluid at a concentration of 20 ppm also eradicated D. ovis. In the field cyhalothrin was evaluated at 20 ppm as a dip wash and at 50 ppm as a jetting fluid. These field trials confirmed the ability of cyhalothrin to eradicate D. ovis from short and long-woolled sheep. The sucking lice, L. ovillus and L. pedalis , were also found to be very susceptible to cyhalothrin at a dip wash concentration of 20 ppm, but it was necessary to treat the predilection sites infested by these parasites twice within a 3-week period to achieve their eradication. Sheep ked (M. ovinus) were eradicated from an infected flock of sheep after plunge dipping in cyhalothrin at 20 ppm.  相似文献   

2.
SUMMARY A synthetic pyrethroid, cypermethrin (NRDC 149), showed activity in killing lice (Damalinia ovis) in the fleece of sheep at concentrations as low as 1 ppm in a dip. In addition concentrations of 5 and 10 ppm showed a persistent effect and prevented reinfestation from contact challenge sheep for 7 and 19 weeks respectively.  相似文献   

3.
Objective   To test strategies for the application of dicyclanil and mid-season crutching to maximise protection of unmulesed sheep against breech strike.
Procedure   Three hundred and eighty unmulesed Merino weaners were randomly allocated to four groups either left untreated or treated by different strategies with 50 g/L dicyclanil. Treatments included breech treatment alone and breech plus body treatment, with two application times, immediately after shearing and 6 weeks after crutching or shearing. To assess protection, larval implants with newly hatched Lucilia cuprina larvae were applied to 10 different sheep from each group at 3, 4, 5 and 6 months after crutching and shearing and assessed for the development of strike at 48 hours. The concentration of dicyclanil was measured in wool samples clipped from the breeches of the test sheep.
Results   All dicyclanil treatments gave significant reduction in strike in comparison to controls up until 4 months after crutching but protection in the sheep treated immediately after shearing had waned at 5 months. Treating at 6 weeks after crutching provided significant reduction ( P < 0.05) in strike for 6 months. Results for strike incidence immediately after shearing and concentration of dicyclanil in the breech wool also suggested improvements in protection by delaying treatment for 6 weeks.
Conclusion   In most environments it should be possible to protect unmulesed sheep against breech strike with a carefully planned integrated control program incorporating strategically timed crutching, shearing and dicyclanil application. Delaying treatment with dicyclanil to at least 6 weeks after shearing or crutching increased the protection provided in comparison to treatment immediately after shearing.  相似文献   

4.
Propetamphos is a new organophosphorous compound with broad spectrum acaricidal and insecticidal activity. Dip wash concentrations of 100 to 200 ppm protect sheep against field challenge for approximately 10 weeks for blowflies, 16 weeks for lice and keds and six weeks for ticks. During laboratory and field trial studies a wash concentration of 125 ppm propetamphos eradicated sheep scab and protected from reinfestation for over four weeks.  相似文献   

5.
The eradication of lice from Merino sheep with wool up to 65 mm long was achieved by spraying insecticide onto the tip of wool over the sides and back. The insecticides used were cyhalothrin and diazinon in small volumes and at high concentration. When infested sheep were sprayed with 100 ml of cyhalothrin 1,500 ppm or diazinon 36,000 ppm, no live lice were seen 23 days after treatment. When treated sheep were challenged with live lice 100 days after treatment an infestation did not establish. Cyhalothrin at a lower concentration of 1,000 ppm gave excellent control but at 500 ppm only fair control was obtained. Diazinon at 24,000 ppm gave probable eradication and at 12,000 ppm excellent control. If a practical method of applying the insecticide to the tip of wool can be developed, then this technique should provide an effective means of eradicating lice in sheep with long wool. This would greatly assist the sheep industry in controlling and eradicating sheep lice.  相似文献   

6.
OBJECTIVE: To assess a ready-to-use formulation of dicyclanil to prevent blowfly strike on Merino sheep under Australian conditions. DESIGN: Randomised clinical trials conducted in an environment house and in the field. PROCEDURE: Two environment house trials were used to measure the protection against flystrike provide by a jetting or a ready-to-use 5% spray-on formulation of dicyclanil over 22 and 31 weeks respectively. Oviposition and strikes were recorded weekly for each sheep. In two field trials the occurrence of strike in Merino sheep treated off-shears or in long wool with dicyclanil or with cyromazine was compared for up to 38 weeks after treatment. Efficacy was assessed by calculating the cumulative percentage of sheep struck. RESULTS: Under environment house conditions, sheep jetted with dicyclanil at 1.50, 0.75 and 0.30 g per sheep developed 0, 8 and 9 strikes respectively during the 22 weeks of the trial, whereas there were 358 strikes present in the placebo group. Sheep sprayed with dicyclanil at 2.25, 1.50 and 0.75 g per sheep developed 5, 11 and 29 strikes respectively between weeks 15 and 31 after treatment, whereas there were 185 strikes present in the untreated controls. In field trials the cumulative percentage of sheep struck reached 1% between weeks 12 to 13 after sheep had been treated with cyromazine. Sheep treated with dicyclanil reached the 1% limit at week 21 after treatment. CONCLUSION: Under Australian field conditions, a ready-to-use 5% spray-on formulation of dicyclanil applied off-shears or to long wool protected Merino sheep from blowfly strike for a period of at least 20 weeks.  相似文献   

7.
Background The occurrence of Tribulus terrestris motor neurone disease (MND) in sheep is linked with grazing Tribulus growing on cultivation paddocks. A previous survey found that the molybdenum (Mo) content of Tribulus growing on uncultivated soils in the Coonabarabran district of New South Wales was 3.03 ppm, but on cultivated soils it was <0.04 ppm. Tribulus contains the purine, xanthosine, which functions as a neuromodulator, and the catabolism of xanthosine is Mo‐dependent. Design To investigate the relationship between xanthosine ingestion and low Mo concentration, eight sheep were fed Mo‐deficient lucerne chaff (<0.10 ppm), the Mo antagonist, sodium tungstate, and xanthosine (25 mg/kg/day) over 18 weeks and then returned to pasture. Results Signs of MND developed in two sheep 30 months later and astrocyte degeneration occurred in all sheep. Conclusion The findings were similar to those observed in sheep with T. terrestris MND, suggesting that the combination of xanthosine ingestion and Mo deficiency may be the cause of this disorder.  相似文献   

8.
The objective of this study was to evaluate the effects of adding 9,10 anthraquinone, a known inhibitor of methanogenesis and sulfate reduction, on blood metabolites, digestibility, and distribution of gas in sheep. In all experiments, we fed a complete pelleted diet that contained 17.5% crude protein and 24.5% acid detergent fiber. In an 8-wk study, feeding up to 66 ppm (dry matter basis) of 9,10 anthraquinone had no adverse effects on blood metabolites including indicators of normal enzyme function, mineral concentrations, and hematological measurements. Feeding 9,10 anthraquinone had no effect on average daily gain, although sheep fed a diet containing 66 ppm of 9,10 anthraquinone numerically gained the least weight. The ruminal molar proportions of acetic acid were decreased (P < 0.05) and the molar proportions of propionic acid were increased (P < 0.05) in sheep fed 1.5 and 66 ppm 9,10 anthraquinone when compared to those fed an unsupplemented diet. In a digestion trial, 9,10 anthraquinone (33 and 66 ppm) had no effect on the apparent digestion of nutrients in the total gastrointestinal tract. In a metabolism study, ruminal gasses were collected by rumenocentesis and analyzed for methane and hydrogen concentrations. Feeding 500 ppm of 9,10 anthraquinone to sheep resulted in a decrease (P < 0.07) in the concentration of methane, but an increase (P < 0.05) in hydrogen concentration of ruminal gas throughout the 19 d of feeding. There was no indication of ruminal adaptation throughout this time. These results are the first to show that 9,10 anthraquinone can partially inhibit in vivo rumen methanogenesis, which supports previous in vitro findings. In addition, at the concentrations used in this study, 9,10 anthraquinone was not toxic to ruminants.  相似文献   

9.
OBJECTIVE: To determine the survival time of Mycobacterium avium subsp paratuberculosis in amitraz-based cattle dip fluid derived from an active dip site in northern New South Wales. PROCEDURE: Following inoculation of triplicate 5 L containers with faeces (0.5 g/L) from a clinical case of bovine paratuberculosis, samples collected up to 8 weeks after inoculation were examined by conventional and radiometric culture. M a paratuberculosis colonies were enumerated on solid media. RESULTS AND CONCLUSIONS: M a paratuberculosis survived in amitraz cattle dip fluid for up to 2 weeks, but not 3 weeks. Where 1% of solids in dip fluid is derived from a clinical case of paratuberculosis, dip fluid may contain viable M a paratuberculosis for at least 2 weeks. These findings have implications for the management of cattle dip sites.  相似文献   

10.
Nicotine used at approximately 2 ppm in 0.25% toxaphene dip wash was found to be 95% effective in the treatment and control of bovine parasitic otitis after dipping clinically affected cattle twice weekly for twelve weeks. Only three of 64 clinically affected animals failed to recover completely following the above treatment regime. The viable nematodes, Rhabditis bovis, which were easily isolated from dip tanks prior to treatment, could no longer be isolated 48 hours following dip tank treatment with nicotine. The above results are very significant since the control of bovine parasitic otitis would greatly enhance the productivity of cattle.  相似文献   

11.
OBJECTIVE: To assess a ready-to-use formulation of dicyclanil to prevent blowfly strike on coarse and fine woolled sheep under New Zealand conditions. DESIGN: Randomized clinical field trials. PROCEDURE: In a first field trial, coarse wooled sheep treated with a ready-to-use, 5% dicyclanil formulation were compared with untreated control sheep for up to 21 weeks. In a second field trial, fine woolled sheep, treated with the same dicyclanil formulation, were compared with untreated sheep for up to 19 weeks. Efficacy was assessed by calculating the aggregated cumulative strike rate. RESULTS: For trial 1 (coarse woolled sheep) the aggregated cumulative strike rate at the end of the trial at week 21 after treatment reached 3.9% and 19.1% for treated and untreated sheep, respectively. For the treated animals the aggregated cumulative strike rate reached the 1% and 2% benchmarks between weeks 11 and 12. For trial 2 (fine woolled sheep) the aggregated cumulative strike rate at the end of the trial at week 19 reached 0.6% and 7.5% for treated and untreated sheep, respectively. Wool length at the time of application did not substantially influence the efficacy of dicyclanil. CONCLUSION: Under New Zealand field conditions, a ready-to-use 5% spray-on formulation of dicyclanil protected coarse woolled sheep for at least 12 weeks and fine woolled sheep for at least 19 weeks.  相似文献   

12.
Three methods of dipping sheep for ectoparasite control, plunge dipping, shower dipping and two models of a James “Mini-shower”(R) (Mk I, Mk II) were compared for efficiency. Usingdiazinon and fenthion-etliyl, at rates recommended by the manufacturers, both plunge and shower dipping gave 6 to 8 weeks protection from flystrike and at least 10 week sprotection from re-infestation by lice. Insecticides applied by both models of “Mini-shower” gave significantly less protection from flystrike (2–3 weeks) than either plunge or shower dipping. Four weeks' protection from louse re-infestation was achieved using insec-ticides applied by the Mk I “Mini-shower”.  相似文献   

13.
The in vivo pediculicidal effectiveness of 1% and 2% formulations of tea tree (Melaleuca alternifolia) oil (TTO) against sheep chewing lice (Bovicola ovis) was tested in two pen studies. Immersion dipping of sheep shorn two weeks before treatment in both 1% and 2% formulations reduced lice to non detectable levels. No lice were found on any of the treated sheep despite careful inspection of at least 40 fleece partings per animal at 2, 6, 12 and 20 weeks after treatment. In the untreated sheep louse numbers increased from a mean (±SE) of 2.4 (±0.7) per 10cm fleece part at 2 weeks to 12.3 (±4.2) per part at 20 weeks. Treatment of sheep with 6 months wool by jetting (high pressure spraying into the fleece) reduced louse numbers by 94% in comparison to controls at two weeks after treatment with both 1% and 2% TTO formulations. At 6 and 12 weeks after treatment reductions were 94% and 91% respectively with the 1% formulation and 78% and 84% respectively with the 2% formulation. TTO treatment also appeared to reduce wool damage in infested sheep. Laboratory studies indicated that tea tree oil 'stripped' from solution with a progressive reduction in concentration as well as volume as more wool was dipped, indicating that reinforcement of active ingredient would be required to maintain effectiveness when large numbers of sheep are treated. The results of these studies suggest significant potential for the development of ovine lousicides incorporating TTO.  相似文献   

14.
Objective To compare the wettability and efficacy of diazinon dip wash made with and without the addition of zinc sulphate.
Design Field experiments using a shower and a plunge dip complemented by in-vitro wettability experiments.
Procedure A flock of infested sheep was divided into groups and treated in a shower dip with clear or cloudy dam water plus up to 1.5% zinc sulphate. Another infested line of sheep was treated using a plunge dip with nil or 1% zinc sulphate. In both experiments, wetting was assessed after dipping and louse counts were conducted for 9 months after treatment. Five in-vitro experiments compared the wettability of dip wash containing diazinon with up to 1.5% zinc sulphate added.
Results In the shower dipping experiment, live lice were found at 1 month after dipping in the cloudy water groups with 0.75%, 1.0% and 1.5% zinc sulphate and at 2 months in the 0.75% zinc sulphate group. No lice were found at subsequent inspections or at any time in the groups that were plunge dipped. Zinc sulphate decreased the amount of dip wash retained by wool staples in all in-vitro experiments (P < 0.05).
Conclusion Zinc sulphate should be considered as a risk factor that could cause failure to eradicate a lice infestation. The risk can be overcome by ensuring that all sheep are saturated at dipping and that the dip wash, and any holding tanks, are agitated throughout the dipping event.  相似文献   

15.
The aim of this investigation was to determine the development and duration of protection in mice or sheep immunised with aromatic-dependent (aro-) Salmonella typhimurium strain CS332, by either parenteral or oral routes. Immunisation of mice by the intraperitoneal or sheep by the intramuscular routes was found to impart protection against oral challenge with the virulent parent S typhimurium strain CS94 as early as seven days after immunisation. In contrast, when immunisation was carried out by the oral route, protection was not evident until three weeks after immunisation. Regardless of the route of immunisation, mice were still partially protected at three months and were fully susceptible at six months after immunisation. In sheep, protection persisted for six months but not 12 months after immunisation. Only parenterally immunised mice and sheep developed high ELISA and, or, agglutinating antibody titres, and cutaneous delayed-type hypersensitivity (DTH) at three weeks after immunisation. Although both antibody and DTH were detectable three months after immunisation of mice with aro- S typhimurium strain CS332, none was detected at six months. Antibody measured by agglutination and ELISA was detectable six months after immunisation in sheep, although no DTH was evident. At 12 months after immunisation low levels of anti-LPS antibody (measurable by ELISA only) were detected in sheep immunised by the intramuscular route.  相似文献   

16.
OBJECTIVE: To quantify stripping in traditional dipping operations and to revise dipping methods, based on prediction of stripping so that a more stable concentration of pesticide in the dipwash is achieved. DESIGN AND METHODS: Plunge and shower dips were operated sequentially according to traditional and revised dipping instructions. Dips were operated by continuous and intermittent replenishment. Samples of mixed dipwash were collected periodically and assayed for pesticide (diazinon) concentration. RESULTS: Diagrammatic representations of pesticide concentration versus number of sheep dipped indicated traditional dipping leads to wide variations in the concentration of pesticide in dipwash during dipping. Intermittent replenishment led to a 'saw-tooth' pattern in the pesticide concentration. Traditional continuous replenishment (using the starting concentration of pesticide) indicated both the rate and extent of stripping was higher in shower dipping. If sufficient sheep were dipped, equilibrium was reached between the rate of pesticide replenishment and removal. An alternative method of dip operation by continuous replenishment, using a low starting concentration of pesticide and a replenishment concentration high enough to offset the pesticide loss through stripping resulted in a more stable concentration of pesticide in the dip. CONCLUSION: Revision of dipping instructions can lead to exposure of sheep to stable concentrations of stripping pesticide during dipping.  相似文献   

17.
The application of polymer matrix ear tags impregnated with 8.5% w/w cypermethrin to 6 wethers following shearing reduced lice to non-detectable levels on 4 of them at 29 weeks after tagging. At the conclusion of the study at 45 weeks the mean count of lice on tagged wethers was 3 per sheep compared to 158 on untreated wethers. In a second experiment, 6 non-infected sheep were treated at shearing with cypermethrin tags, 6 with 25 g/l cypermethrin backline formulation, 6 with tags plus backline and 6 were left untreated. Each group was exposed to 6 sheep with moderate to heavy infestations of lice. Compared to controls, all treatments delayed infestation, but cypermethrin tags gave no longer protection than backline treatment. All sheep were infested by 17 weeks after commencement of the study. At 45 weeks mean counts of lice were 38, 27, 20 and 74 respectively for sheep treated with tags, backline formulation, backline plus tags and untreated. Possible reasons for the better effect observed from applying tags to infested sheep than to sheep which were not infected at application but which were subsequently exposed to infested sheep are discussed.  相似文献   

18.
Five Merino and five Dorper sheep were artificially infested with the sheep scab mite Psoroptes ovis and the effect of infestation on their haematology, serum protein levels and live mass recorded for a period of 14 weeks. The reaction of the Merino sheep to infestation was more severe than that of the Dorper sheep. Haematological values fluctuated within the normal range during the assessment period. The mean haemoglobin concentration of the Merino sheep declined until antiparastic treatment was administered 10 weeks after infestation, after which it gradually increased. The lymphocyte counts of both breeds of sheep declined from 2 weeks to 10 weeks post-infestation, but increased after treatment, while the highest eosinophil counts were recorded in the Merino sheep at the height of the acute disease 8-10 weeks post-infestation. Serum albumin values for both breeds and serum globulin values for the Merino sheep were higher than normal during the entire 14-week observation period. A decrease in serum albumin and an increase in serum globulin concentration occurred at the height of infestation in both breeds. The mean live mass of a second group of five infested Merino sheep decreased by 6.4 kg over a 16-week period compared to a gain of 4.56 kg for five infested Dorper sheep.  相似文献   

19.
The effect of dietary selenium on humoral immunocompetence of ponies   总被引：1，自引：0，他引：1  
Fifteen Shetland ponies were used in a 7-wk trial to study the effect of supplemental Se on humoral antibody production. Four 3-yr-old, five 2-yr-old and six yearling ponies were depleted of Se before being assigned randomly to either a low Se (.02 ppm) or higher Se (.22 ppm) diet. Each pony was challenged antigenically with 2 ml of sheep packed red blood cells upon receiving its respective diet and again 2 wk post-treatment. Blood samples were drawn weekly and assayed for glutathione peroxidase activity, Se and immunoglobulin concentration and antibody titers. Compared with those ponies receiving the low Se concentrate, ponies receiving the Se-supplemented diet had higher (P less than .01) glutathione peroxidase activities and blood Se concentrations during the later weeks of the experiment. An enhanced primary response was observed in Se-supplemented ponies as evidenced by increased hemagglutination titers. Higher IgG concentrations (P less than .01) also were observed in the Se-supplemented group. Dietary Se concentration of .02 ppm was inadequate for optimum immune function in the equine.  相似文献   

20.
Male lambs of the pure breeds Texel, Flemish milk sheep, and Finnish landrace, and of the crossbreds Texel x Friesian milk sheep, Texel x Finnish landrace, Suffolk x Friesian milk sheep, and Finnish landrace x Ile de France were fed hay and concentrates, the latter differing only in the content of copper. At high (+/- 35 ppm) and at moderately low (+/- 10 ppm) copper levels in the concentrate, breed differences in the accumulation of copper in the liver were studied. Hepatic Cu-levels increased significantly in the case of the high Cu-fed animals, but great differences in the metabolism of excessive amounts of dietary Cu exist between the particular breeds and crossbreds. The Texel breed was most susceptible to an excess of dietary Cu and the Finnish landrace was the least susceptible breed, while the Flemish milk sheep and the crossbreds were intermediate. In blood serum, the enzyme activities of sorbitol dehydrogenase, lactate dehydrogenase, gamma-glutamyl transferase, and glutamic oxaloacetic transaminase were increased to a greater or less extent in the high Cu-fed animals, but the correlation with hepatic Cu-content was poor. For the most susceptible breeds, even a level of 10 ppm Cu in a ration with nearly equal amounts of hay and concentrate is insufficiently low for the prevention of Cu-accumulation in the liver.  相似文献   

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