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1.
Burke JM Kaplan RM Miller JE Terrill TH Getz WR Mobini S Valencia E Williams MJ Williamson LH Vatta AF 《Veterinary parasitology》2007,147(1-2):89-95
FAMACHA is a practical on-farm system designed to provide small ruminant producers a tool for improving their management of Haemonchus contortus infections. Although this system has become very popular and widely accepted by small ruminant producers in many regions of the southern United States, there is very limited data reported on the effectiveness of the FAMACHA system when performed by farmers. The objective of this study was to evaluate the accuracy of the FAMACHA system for on-farm use by small ruminant producers during the summer season. Small ruminant producers from Georgia, Louisiana, Florida, and Puerto Rico were trained to use the FAMACHA system by veterinarians and scientists experienced with this method. FAMACHA scores were assigned at least every 2 weeks by producers to weaned and mature sheep (n=552) and goats (n=676) of various breeds and ages between April and September 2004. At intervals that varied among farms from 2 to 8 weeks, researchers determined body condition scores (BCS; 1=thin and 5=fat) and collected blood and feces from a group of animals selected randomly to determine packed cell volume (PCV) and fecal egg counts (FEC). Two separate anemia thresholds were evaluated; these were defined by either FAMACHA score (>or=3 versus >or=4) or PCV (or=3 were considered anemic and PCV cutoff was or=3 were considered anemic and PCV cutoff was 相似文献
2.
Kaplan RM Burke JM Terrill TH Miller JE Getz WR Mobini S Valencia E Williams MJ Williamson LH Larsen M Vatta AF 《Veterinary parasitology》2004,123(1-2):105-120
Recent studies on sheep and goat farms in the southern United States indicate that multiple-anthelmintic resistance in Haemonchus contortus is becoming a severe problem. Though many factors are involved in the evolution of resistance, the proportion of the parasite population under drug selection is believed to be the single most important factor influencing how rapidly resistance develops. Therefore, where prevention of resistance is an important parallel goal of worm control, it is recommended to leave a portion of the animals untreated. Recently, a novel system called FAMACHA was developed in South Africa, which enables clinical identification of anemic sheep and goats. When H. contortus is the primary parasitic pathogen, this system can be applied on the farm level to reduce the number of treatments administered, thereby increasing the proportion of the worm population in refugia. Since most studies validating the FAMACHA method have been performed in South Africa, it is important that the method be tested in other regions before its use is broadly recommended. We performed a validation study of FAMACHA by testing the system in sheep (n = 847) and goats (n = 537) of various breeds and ages from 39 farms located in Arkansas, Georgia, Louisiana, Florida, and the US Virgin Islands. The color of the ocular conjunctiva of all animals were scored on a 1-5 scale using the FAMACHA card, and blood samples were collected from each animal for determination of packed cell volume (PCV). Fecal samples were also collected from a majority of the animals tested for performance of fecal egg counts (FEC). Correlations between PCV and eye scores, PCV and FEC, and FEC and eye scores were all highly significant for both sheep and goats (P < 0.001). Data for both FAMACHA scores and PCV were evaluated using two separate criteria for anemia: eye score values of 3, 4 and 5 or 4 and 5, and PCV values of < or =19 or < or =15 were considered anemic. Specificity was maximized when eye score values of 4 and 5 were considered anemic and PCV cut off for anemia was < or =19, but sensitivity was low. In contrast, sensitivity was 100% for both sheep and goats when eye score values of 3, 4 and 5 were considered anemic and PCV cut off was < or =15, but specificity was low. In both sheep and goats, predictive value of a negative was greater than 92% for all anemia and eye score categories, and was greater than 99% for both eye score categories when an anemia cutoff of < or =15 was used. Predictive value of a positive test was low under all criteria indicating that many non-anemic animals would be treated using this system. However, compared to conventional dosing practices where all animals are treated, a large proportion of animals would still be left untreated. These data indicate that the FAMACHA method is an extremely useful tool for identifying anemic sheep and goats in the southern US and US Virgin Islands. However, further studies are required to determine optimal strategies for incorporating FAMACHA-based selective treatment protocols into integrated nematode control programs. 相似文献
3.
A previously developed multiple regression algorithm was used as the basis of a stochastic model to simulate worm burdens in sheep naturally infected with Haemonchus contortus over five consecutive Haemonchus seasons (November to January/February) on a farm in the summer rainfall region in South Africa, although only one season is discussed. The algorithm associates haemoglobin levels with worm counts in individual animals. Variables were represented by distributions based on FAMACHA(?) scores and body weights of sheep, and Monte Carlo sampling was used to simulate worm burdens. Under conditions of high disease risk, defined as the sampling event during the worm season with the lowest relative mean haemoglobin level for a class of sheep, the model provided a distribution function for mean class H. contortus burdens and the probability of these occurring. A mean H. contortus burden for ewes (n=130 per sample) of approximately 1000 (range 51-28,768) and 2933 (range 78-44,175) for rams (n=120 per sample) was predicted under these conditions. At the beginning of the worm season when the risk of disease was lowest (i.e. when both classes had their highest estimated mean haemoglobin levels), a mean worm burden of 525 (range 39-4910) for ewes and 651 (range 37-17,260) for rams was predicted. Model indications were that despite being selectively drenched according to FAMACHA(?) evaluation, 72% of the ewes would maintain their mean worm burden below an arbitrarily selected threshold of 1000 even when risk of disease was at its highest. In contrast, far fewer rams (27%) remained below this threshold, especially towards the end of the worm season. The model was most sensitive to changes in haemoglobin value, and thus by extrapolation, the haematocrit, which is used as the gold standard for validating the FAMACHA(?) system. The mean class haemoglobin level at which there was a 50% probability of worm burdens being ≤ 1000 worms was 7.05 g/dl in ewes and 7.92 g/dl in rams. 相似文献
4.
Control of gastrointestinal nematodes (GIN) in small ruminants in regions of the world where anthelmintic resistance is prevalent must rely on more than just chemical deworming strategies. The objective of this experiment was to compare two integrated treatment protocols for control of GIN (primarily Haemonchus contortus in this region) using anthelmintics, copper oxide wire particles (COWP) and FAMACHA(?), compared to traditional anthelmintic use only. Three separate trials were conducted on mature ewes, weaned goats, and weaned lambs in which three deworming management strategies were applied: 1) all animals were dewormed with levamisole at four week intervals (LEV), 2) individual animals were dewormed with moxidectin when scored≥4 (ewes) or ≥3 (kids and lambs) using FAMACHA(?) (FAM/MOX), 3) all animals were dewormed with moxidectin initially and again with COWP (2g) when group mean FEC exceeded 500 (ewes), 3000 (kids), or 1000 (lambs) eggs/g (MOX/COWP). In this final group, during periods between group treatments, individual animals were dewormed with albendazole and levamisole according to FAMACHA(?) score. Fecal egg counts (FEC) and blood packed cell volume (PCV) were determined every 7 days and body weight every 28 days for 30, 20, or 16 weeks in ewes, goats, and lambs, respectively. Efficacy of levamisole was 83.4-86.4%, efficacy of moxidectin was 93.5-100%, and efficacy of COWP was 10.8-98.1% among the three trials. The mean number of deworming treatments per animal that occurred for the LEV, FAM/MOX, and MOX/COWP groups, respectively, was 7.9, 0.6, and 2.5±0.4 (P<0.001) for ewes, 5.2, 1.6, and 3.4±0.3 (P<0.001) for goats, and 4.0, 1.7, and 3.6±0.2 (P<0.001) for lambs. Production (body weight of lambs weaned from ewes or final body weight of kids and lambs) was similar among management strategy groups for ewes and kids, but FAM/MOX lambs were lighter by the end of the trial (P<0.003). While more time and labor was required to use the FAMACHA(?) system, a more conservative use of anthelmintics occurred in the FAM/MOX group. 相似文献
5.
Because of a high prevalence of anthelmintic resistance and consumer demand for chemical free meat products, management tools to minimize the need for deworming are needed. The objective was to examine the effectiveness of grazing sericea lespedeza (SL) in a mixed grass or a pure forage system for control of gastrointestinal nematodes (GIN); in other words pasture systems included grass, grass plus SL, or SL alone (Experiments 2 and 3). Selective use of copper oxide wire particles (COWP) based on the FAMACHA(?) system was used to aid in GIN control. In Experiment 1, lambs co-grazed bermudagrass (BG; n=21) or SL in a mixed grass pasture (SLM; n=22) with dams for 14 days. In Experiment 2, lambs grazed BG (n=14), SLM (n=13), or pure SL (SLP; n=13) pastures for 56 days. In Experiment 3, doe kids grazed BG (n=12), SLM (n=13), or SLP (n=13) for 84 days. Animals were fed a 16% crude protein supplement based on NRC requirements and estimated forage quality of pastures, so that 454, 389, and 200 g/lamb (Experiment 2), or 454, 300, and 150 g of supplement/goat (Experiment 3) was fed to BG, SLM, and SLP, respectively. Animals were dewormed with COWP if FAMACHA(?) was >3. Coprocultures were conducted to identify GIN genus. In Experiment 1, FEC were reduced in lambs grazing SLM compared with BG pastures. In Experiment 2, FEC were reduced in SLP compared with BG lambs on all days, and reduced in SLM compared with BG lambs on day 56. Initially, Haemonchus contortus was the predominant nematode, but the population shifted to other species in the SL groups by the end of the study. The mean number of dewormings/lamb was 0.71, 0.20, and 0.21±0.13 for BG, SLM, and SLP groups, respectively. In goats in Experiment 3, Trichostrongylus spp. was the predominant nematode in May and June and H. contortus in July. There was little meaningful effect of forage treatments on GIN infection in kids. Because H. contortus was not the predominant nematode in kids, the integrated approaches used may not have been effective in controlling GIN. Grazing SL was effective for GIN control in lambs in early summer, but the effect was delayed in lambs grazing a mixed SL/grass pasture unless lambs initially grazed with dams. An integrated approach used that included SL grazing and COWP for deworming was effective in lambs. 相似文献
6.
Test sensitivity and specificity for the FAMACHA(?) clinical test for anaemia due to haemonchosis have previously been shown to be adequate in differentiating between heavily/less heavily infected sheep, but these properties give no objective guidance for setting the optimum threshold at which anthelmintic treatment should occur. The aim of this work was to use Receiver Operating Characteristic (ROC) curves to evaluate the diagnostic accuracy of FAMACHA(?) testing by estimating the area under the ROC curve, and to use two-graph ROC curves to decrease subjectivity in selecting treatment thresholds on two farms with contrasting management. Test diagnostic accuracy, and thus discriminating power as determined by the area under the ROC curves, ranged from "moderate to good" on the first farm, and from "moderate to high" on the second farm for haematocrit (the Gold Standard for the test) cut-offs of ≤ 22% and ≤ 19% on both farms respectively. Accuracy of classification between haematocrit cut-offs was not significantly different within farms, but did differ significantly between farms, with test accuracy being highest on the second farm at both haematocrit cut-offs (p<0.05). The results also showed the suitability of the two-graph ROC curve approach for discriminating not only between different levels of accuracy of evaluators, but also to give an indication of the so-called ROC cut point (i.e. the desired threshold level) at which animals should be treated for a given level of risk of loss. The approach appears to have the potential not only to validate the diagnostic accuracy of the test across the complete testing range (i.e. all FAMACHA(?) categories from 1 to 5), but also to compensate for such inaccuracy by allowing objective adjustment of the threshold treatment level according to the output of the two-graph ROC method. 相似文献
7.
Burke JM Whitley NC Pollard DA Miller JE Terrill TH Moulton KE Mosjidis JA 《Veterinary parasitology》2011,181(2-4):345-349
The objective of three experiments was to determine the impact of supplementing sericea lespedeza (Lespedeza cuneata; SL) in three concentrations in a loose or pelleted diet on gastrointestinal nematodes (GIN) in small ruminants. Experiments on lambs were conducted at the USDA, Agricultural Research Service in Booneville, AR (Exp. 1) and at Louisiana State University in Baton Rouge, LA (Exp. 2); an experiment on goat kids occurred at University of Maryland-Eastern Shore (Exp. 3). Exp. 1 used crossbred hair sheep lambs naturally infected with GIN that were randomly allocated to diets containing 0, 25, 50, and 75% SL diets (n=11 or 12/diet). Exp. 2 consisted of Haemonchus contortus-inoculated crossbred wool breed lambs that were blocked by gender and FEC and randomly assigned to 0, 25, 50, or 75% SL diet (n=8/diet). Fecal egg counts (FEC) and blood packed cell volume (PCV) were not influenced by SL supplementation in Exp. 1 and 2. Exp. 3 consisted of naturally GIN infected Boer crossbred goat kids in individual pens. Kids were blocked by FEC and randomly allotted to treatments of 0, 20, 40, or 60% SL with 9-13 goats/diet. The more SL fed, the greater the reduction in FEC (P<0.001). There was an increase in PCV in SL fed goats (P<0.001). Larval speciation at the end of the experiment indicated that feces from control animals produced 43% H. contortus larva while 20, 40 and 60% SL resulted in 39%, 35% and 31% H. contortus larvae, respectively. Feeding dried SL may be less effective in lambs than kids, though concurrent studies must be conducted to confirm this. 相似文献
8.
The effective application of targeted selective treatment (TST) against gastro-intestinal nematodes depends on the accurate identification of those animals in need of anthelmintic treatment. Finding cost and labour effective measures to identify such animals is paramount. This study tested the efficacy of three indicators on lambs in a farm in Eastern Algeria: anaemia score (FAMACHA(?)), diarrhoea score (DISCO) and weight gain. These were contrasted against traditional parasitological infection measures (nematode eggs per gram of faeces: EPG). Thirty lambs were used in the study; every second month they were sampled (FAMACHA(?), faecal samples for EPG and DISCO, weight gains) and two of the original 30 lambs were necropsied for adult worm counts. The main gastro-intestinal nematodes were Teladorsagia circumcincta, Marshallagia marshalli, Nematodirus helvetianus, Trichostrongylus vitrinus, and Haemonchus contortus. DISCO proved to be the most effective indicator correctly identifying 80% of the sheep in need of treatment. This was followed by FAMACHA(?) with a 50% accuracy level and finally weight gains, which were not found to be a useful indicator at all. 相似文献
9.
AIMS: To investigate the epidemiology of Yersinia species in healthy goats in New Zealand, in particular to determine the prevalence of farms with infected goats, the prevalence of infected goats on those farms, the serotypes involved, and potential risk factors for carriage. METHODS: A cross-sectional study of the prevalence of Yersinia infection in infected flocks in a study population of thirty commercial goat farms in the Manawatu region of New Zealand. RESULTS: Infection was detected on 60% of farms in an initial study. In a prevalence study on 18 infected farms, the study population comprised 6770 animals (mean of 376, median of 175 and range of 36 to 1295 goats/farm). Of 902 goats (296 < 1 year, 178 1 to 2 years, and 428 > 2 years) sampled from the study population, 135 (73 < 1 year, 21 1 to 2 years, and 41 > 2 years) were excreting Yersinia spp, giving an overall prevalence of 14.97% (95% confidence interval [CI]; 12.8 to 17.4) with individual farm prevalences ranging from 0.0 (+ 7.9) to 58.14% (95% Cl, 43.3 to 71.6). Goats < 1 year were more likely to be infected than 1-2 year and > 2 year old animals (relative risk [RR] = 2.1; 95% Cl, 1.3 to 3.3) and 2.6 (95% Cl, 1.8 to 3.6) respectively), but there was no significant difference between risks for 1 to 2 year and > 2 year goats (RR = 1.2; 95% CI, 0.7 to 2.0). Yersinia enterocolitica was the most common species isolated in the youngest age group, with prevalence declining with increasing age, while other species were more common in the older age groups. CONCLUSION: Yersinia infections were common in goats in the study region, with younger animals apparently more susceptible to infection and in particular to infection with Y enterocolitica. The prevalence on infected farms appeared to decrease as flock size increased and to increase as stocking rates and the number of paddocks grazed increased. 相似文献
10.
The FAMACHA system for managing haemonchosis in sheep and goats by clinically identifying individual animals for treatment 总被引：1，自引：0，他引：1
Escalating anthelmintic resistance has made it essential to develop alternative ways of worm management for reducing selection for worm resistance, and one of the most promising approaches is to treat only those animals unable to cope with worm challenge, thus favouring unselected worms originating from untreated animals. Only clinical evaluation of anaemia (FAMACHA system) and the body condition score are regarded as being of practical value or having potential, respectively, for repeatedly examining flocks or herds and identifying individuals for treatment. Only the FAMACHA system has been tested well enough for use under practical farming conditions. However, further investigation is needed on its effect on animal production, and methods to reduce labour. Trials over several seasons showed that most sheep under severe Haemonchus contortus challenge required no, or only one treatment over a full summer season. A small minority (usually < 5%) needed more than two treatments. Most sheep could cope without regular treatment. With sufficient training, clinical evaluation of anaemia was found reliable for practical use. The overwhelming majority of trainees (some poorly literate) were able to implement the FAMACHA system successfully. The dynamics of haemonchosis in a flock can easily be monitored. Farmers, farm workers and veterinarians all rated the system very highly (> 80%) and treatment costs dropped by approximately 58%. The heritability of FAMACHA values obtained by clinical evaluation was high at 0.55 +/- 0.17% in a Merino stud with +/- 550 young rams and ewes which were the progeny of 21 sires. The FAMACHA system may not be as applicable to goats as to sheep, but further work is necessary. The main benefits of the system are the reduction in treatments, its use for discriminating between animals of varying ability to cope with infection (thus allowing genetic selection), and its lowering of selection pressure on H. contortus for anthelmintic resistance. 相似文献
11.
Seroprevalence of F4+ enterotoxigenic Escherichia coli in regions with different pig farm densities.
Sera of young sows from 135 closed Belgian pig breeding farms were examined for the presence of serum antibodies specific for the F4 fimbrial antigen of enterotoxigenic Escherichia coli (ETEC). Since 80% of all pig farms in Belgium are located in the provinces West-Vlaanderen (44%, approximately 18 farms/10 km2), Oost-Vlaanderen (20%, approximately 9 farms/10 km2), Antwerpen (10%, approximately 5 farms/10 km2) and Vlaams-Brabant (6%, approximately 3 farms/10 km2), the farms examined were randomly selected in these four regions. On 68% of all tested farms, sows were not vaccinated against enteric colibacillosis. In general, 65% of these non-vaccinated farms were F4-seropositive (mean optical density [OD405] >0.5) of which 38% were weakly (mean OD405 = 0.5-1.0), 21% moderately (mean OD405 = 1.0-2.0) and 6% strongly positive (mean OD405 > or =2.0). These percentages showed major differences between the four provinces. In Vlaams-Brabant, only 31% of non-vaccinated farms were seropositive, of which most were regarded as weakly positive. In Antwerpen, Oost- and West-Vlaanderen however, this percentage was clearly higher and respectively 68, 71, and 79% of non-vaccinated farms were seropositive, of which most were weakly positive. These observations indicate that F4+ ETEC is widely spread and highly prevalent on non-vaccinated pig breeding farms in Belgium. Moreover, an increasing F4-seropositivity with increasing pig farm density suggests a possible influence of the swine density on the prevalence of F4+ ETEC infections. 相似文献
12.
High levels of anthelmintic resistance in gastrointestinal nematodes (GIN) of small ruminants have created the need for animals with greater resistance to these parasites. The objective of this experiment was to evaluate the effectiveness of the FAMACHA system in identification of parasite resilient/resistant offspring, and thus identification of stud rams with greater resilience/resistance. Katahdin ewes bred in separate groups to two sires to lamb in spring (2004, 2005: Ram A and Ram B; 2006, 2007: Ram C and Ram D) at the USDA, Agricultural Research Station in Booneville, Arkansas produced 20-40 offspring/sire each year. Ewes and lambs grazed mixed grass (predominantly bermudagrass and ryegrass) pastures and were supplemented with corn/soybean meal between 30 days pre- and 60 days post-lambing (ewes) and starting 45 days of age until weaning (lambs; 95.0+/-0.6 days of age). Blood samples and feces were collected from the lambs to determine blood packed cell volume (PCV) and fecal egg counts (FEC) and FAMACHA scores were determined at 90, 120, and 150 days of age. Lambs were dewormed if anemic (PCV<19% or FAMACHA score >2) and data removed within 30 days after deworming. Data were analyzed for the 2004/2005 and 2006/2007 groups using general linear models with year, sex of lamb, and sire nested within year as variables. Sire differences were detected (P<0.05 or less) for PCV and FAMACHA at all time points, but not FEC. There tended (P<0.10) to be sire differences for FEC at 90 and 120 days of age, but not at 150 days of age. Lambs sired by Ram D were dewormed less by 150 days of age than those sired by Ram C. The FAMACHA system can be used to identify superior sires for parasite resilience/resistance, thus increasing flock resilience, and perhaps resistance. 相似文献
13.
Costa CA Vieira LD Berne ME Silva MU Guidoni AL Figueiredo EA 《Veterinary parasitology》2000,88(1-2):153-158
The variability between and within breeds with respect to nematode egg counts (EPG), packed cell volume (PCV) and hemoglobin (Hb) was studied in 36 yearling female goats of the Caninde (15), Bhuj (6) and Anglo-Nubian (15) breeds, exposed to Haemonchus contortus. Nematode-free goats were turned to a contaminated paddock in late February. From then on, fecal egg per gram counts (EPG), packed cell volume (PCV) and hemoglobin (Hb) were determined at 2-week intervals up to Week 18. The EPG, transformed as [log(EPG + 75)], varied (P < 0.01) between goats within breeds and between weeks of exposure, but not between goat breeds (P > 0.05). PCV and Hb were affected by goat breeds (P < 0.05), by goats within breeds (P < 0.01) and by weeks of exposure (P < 0.01). Anglo-Nubians had higher (P < 0.01) PCV and Hb than Caninde; Bhuj had intermediate values. There were two EPG rises; one between Weeks 6 and 10 and the other between Weeks 14 and 16. The within breed variability was marked during the EPG rise on Week 6, when individual egg counts ranged from 130 to 2500. The EPG rises coincided with drops in Hb. PCV presented a similar trend, though not as marked. Haemonchus was responsible for more than 95% of nematode eggs counted. Considering the goat as experimental unit, the correlation coefficients (r) were: -0.45, P = 0.0064, between log(EPG + 75) and PCV; and -0.53, P = 0.0009, between log(EPG + 75) and Hb. The negative correlation between egg counts and blood values suggested breed differences in PCV and Hb were related to resistance to H. contortus infection and/or to its effects. 相似文献
14.
A study on the epidemiology and seasonal dynamics of gastrointestinal nematode infections of sheep was carried out in a semi-arid region of eastern Ethiopia for 2.5 years (May 2003 to September 2005). The experimental flock comprised a total of 60 Black Head Ogaden sheep, consisting of four equal groups of young male and female and old male and female sheep. These grazed on communal pastures together with a larger university flock, as well as with animals owned by neighbouring small-holder farmers. A new experimental flock was established each year of the study. Parasitological data (EPG, faecal culture L3, PCV and FAMACHA estimates) and animal performance (weight change) were recorded each month on all experimental animals. In addition, four tracer lambs were assigned each month to the flock to determine the seasonal patterns of infective larvae acquired from pasture. Results showed distinct seasonal patterns associated with the bi-modal annual rainfall. High levels of infection occurred during the short and long rain seasons with peaks occurring in May and September of each year. Haemonchus contortus was the most prevalent parasite, followed by Trichostrongylus spp., with a number of other nematode species being occasionally recorded. H. contortus showed and increased propensity to undergo arrested development during the dry seasons. Correlations between EPG and PCV, EPG and FAMACHA eye scores, and PCV and FAMACHA eye scores were all highly significant (P<0.001). However, there was no significant association between the EPG and LW of the study animals during each study year. This information will provide a basis for developing epidemiologically based control strategies for gastrointestinal nematode parasites that are appropriate for flocks owned by small-holder farmers of semi-arid areas of eastern Ethiopia. 相似文献
15.
Joshi BR Kommuru DS Terrill TH Mosjidis JA Burke JM Shakya KP Miller JE 《Veterinary parasitology》2011,178(1-2):192-197
Effect of sericea lespedeza [SL; Lespedeza cuneata (Dum-Cours.) G. Don.] leaf meal feeding was evaluated in two experiments in indoor reared goats with experimental infection of Haemonchus contortus larvae. In the first experiment, ten 8-10 month old male Spanish and Alpine cross kids pair matched for body weight and age were fed SL or bermudagrass [BG; Cynodon dactylon (L.) Pers.] hay one week before infection and were infected with 5000 H. contortus L(3). The animals were maintained on the same diet for the remaining period and were slaughtered 28 days post-infection (DPI) to determine the establishment of incoming infective larvae. Goats fed SL had lower establishment (P<0.05) of H. contortus larvae than that of the control goats fed BG hay. In the second experiment, twenty-five 8-10 months old male Alpine cross, Saanen, Nubian×Saanen and Spanish kids reared in confinement on BG were experimentally infected with 5000 H. contortus L(3). On 35 DPI, the animals were allocated to two groups after blocking by fecal egg count (FEC), and one group was fed SL leaf meal (n=13), and another control group remained on BG (n=12). Four goats/group were slaughtered successively on days 7, 14, and 28 days post SL feeding, except on day 7, when five SL fed goats were slaughtered. Fecal egg counts and blood packed cell volume (PCV) were measured at weekly intervals and worm count, female worm fecundity, worm length and mucosal eosinophils, mast cells and globule leucocytes were measured after slaughter. Goats fed SL had a lower FEC (P<0.05) one week after feeding, as compared to those fed on BG, and the values remained at low level thereafter. Similarly, PCV was also significantly affected by feeding (P<0.01), and feeding and time interaction (P<0.05). However, worm burden, female worm fecundity, parasite length, and mucosal inflammatory cell count were similar between the groups. Feeding SL reduced the establishment of infective larvae and FEC of H. contortus in experimental studies and this plant could be used for biological control of parasite infection under field conditions to limit the harmful effects of the parasites in goats. 相似文献
16.
A faecal egg count reduction test was conducted on a sheep farm with suspected avermectin resistance. Five groups of 10 sheep were formed. Group 1 was the untreated control group. Groups 2-5 were treated according to weight with the recommended dose of, respectively, levamisole, doramectin, moxidectin or albendazole. Resistance was found in the sheep treated with doramectin (15% efficacy) and albendazole (87% efficacy). Levamisole and moxidectin were 100 and 99% effective, respectively. Larval identification of the faecal cultures of the doramectin-treated sheep revealed 100% Haemonchus contortus larvae. After albendazole treatment, 77% of the cultured larvae were H. contortus and 23% Teladorsagia/Trichostrongylus. Because there is a lot of trade in sheep on the farm, it is probable that the resistant worms were introduced with livestock from other farms than being selected on the farm. 相似文献
17.
Resistance of Teladorsagia circumcincta in goats to ivermectin In 2005, suspected ivermectin resistance of gastrointestinal nematodes was investigated in 17 goats on a farm in the Netherlands, using a faecal egg count reduction test combined with faecal larval cultures. Eight goats were treated orally with 0.2 mg/ kg ivermectin on 1 August 2005 and the other nine goats served as untreated controls. Faeces were collected from all goats on 1 August and on 12 August. Faecal egg counts were reduced by 80.6% in goats receiving ivermectin. On the basis of faecal larval cultures and the egg counts, ivermectin was found to be 100% effective against Haemonchus contortus, 15.0% effective against Teladorsagia circumcincta, and 93.3% effective against Trichostrongylus spp. The effect of levamisole and oxfendazole on gastrointestinal nematodes was also evaluated. Nine goats were treated subcutaneously with 5 mg/kg levamisole and seven goats orally with 4.5 mg/kg oxfendazole on 12 September On the basis of faecal egg counts performed on 12 and 22 September, levamisole reduced the total egg count by 95.4% and oxfendazole reduced the egg count by 85.8%. Differentiation of pooled faecal larval cultures revealed that levamisole was 99.9% effective against H. contortus, 81.9% effective against T. circumcincta, and 99.5% against Trichostrongylus spp. Oxfendazole was 75.5% effective against H. contortus, 33.2% effective against T. circumcincta, and 100% effective against Trichostrongylus spp. On 28 October the nine goats that were still present on the farm were orally treated with 0.4 mg/kg ivermectin. Faecal egg counts and differentiation of pooled larval cultures of faecal samples collected on 28 October and 9 November, respectively, revealed that total egg counts were reduced by 93.1%. Ivermectin was 49.1% effective against T. circumcincta but 100% effective against H. contortus and Trichostrongylus spp. Thus H. contortus appears to be resistant to oxfendazole and T. circumcinta appears to be resistant to oxfendazole and ivermectin. This is the first documented case of ivermectin resistance of a gastrointestinal nematode of small ruminants in the Netherlands. 相似文献
18.
López-Soria S Segalés J Rose N Viñas MJ Blanchard P Madec F Jestin A Casal J Domingo M 《Preventive veterinary medicine》2005,69(1-2):97-107
An exploratory case-control study was carried out in Spain in 2002/2003, involving 62 pig farms of different production systems to assess risk factors that, in association with PCV2 infection, induce postweaning multisystemic wasting syndrome (PMWS) expression. To achieve this objective two groups of farms selected according to their PMWS status were compared: "cases" (farms with clinical PMWS, n = 32) and "controls" (farms without clinical PMWS, n = 30). A filled-in questionnaire and 45 blood samples (15 sows, and two groups of 15 pigs of 12 and 20 weeks of age, respectively) were obtained from each farm. Additionally, two to three diseased pigs were necropsied and relevant tissues to diagnose PMWS collected when PMWS was clinically suspected ("case" farms). A statistical analysis to compare "case" versus "control" farms was performed with the variables obtained from the questionnaire (191 variables) and the serologic test results (20 variables). Data were analysed using conditional logistic regression with a nested n:m matched design taking into account the farm size. Three variables were found significant in the final model: two related to vaccination scheme and one to PCV2 seroprevalence in growing pigs. Vaccination of gilts against PRRSV increased the odds of PMWS expression and vaccination of sows against atrophic rhinitis was related to decreased odds of the disease; however, the possibility that those two factors could be spurious effects (due to the small sample size) or confounding variables cannot be ruled out. On the other hand, a higher prevalence of antibodies to PCV2 at 12 weeks of age was observed in pigs from "case" farms than in pigs from "control" farms. This result suggests that an earlier infection with PCV2 might be a risk factor for PMWS expression. 相似文献
19.
Chiejina SN Musongong GA Fakae BB Behnke JM Ngongeh LA Wakelin D 《Veterinary parasitology》2005,128(1-2):29-40
Although Nigerian West African Dwarf (WAD) goats are relatively resistant to infection with Haemonchus contortus and are also trypanotolerant, natural outbreaks of both infections are known to occur. Despite their relative resistance to H. contortus WAD goats nevertheless show variability in response phenotype and it was of interest to examine the effect of this variability on the outcome of concurrent trypanosome infection. Trypanosoma brucei infections were established in goats that were initially classified as good or poor responders to H. contortus. Thirty-nine goats were exposed to an escalating infection with H. contortus, and on the basis of their mean faecal egg counts (FEC) were allocated to high FEC (poor responders, 18 goats with the highest FEC) or low FEC (good responders, 18 goats with the lowest FEC) classes. Nine uninfected naive control goats were included to provide reference baseline values. Retrospective analysis of parasitological and pathological parameters after allocation into high/low FEC classes showed that FECs differed significantly, in both classes packed cell volume (PCV) values fell relative to naive controls, neither class lost weight and both generated marked IgG responses. All goats received anthelmintic on day 61, half of each group was infected with 50 million trypanosomes and on day 67, excepting the controls, all goats were challenged with 3000 L3 of H. contortus. Trypanosome parasitaemia was generally low, and marginally, but not significantly, higher in the low compared with high FEC class, peaking 12-16 days after exposure in both groups and then falling to below microscopically detectable levels (although still detectable by sub-inoculation into mice) by week 3. At autopsy (days 109/110), worm burdens were significantly higher in the trypanosome-infected goats from the high FEC class, relative to all other groups. Trypanosome infected goats showed a tendency (although not significant) towards higher FEC and, irrespective of their FEC class, had lower PCV values although body weight did not vary significantly. All goats challenged with H. contortus had higher antibody levels than naive controls, but neither trypanosome infection nor FEC class affected the magnitude of responses. These results confirm that WAD goats comprise a range of response phenotypes to initial H. contortus infection and that trypanotolerance is a key trait of this breed. Although immunity to nematode infection develops even in poor responders, these animals harbour higher nematode burdens during concurrent infection with T. brucei. 相似文献
20.
Anthelmintic efficacy of levamisole against induced infections with 7- and 21-day-old Haemonchus contortus, Ostertagia circumcincta, Trichostrongylus axei, and T colubriformis was evaluated as an oral drench in goats. Group 1 (n = 8) was not treated, group 2 (n = 8) was given 3.96 mg of levamisole/kg of body weight, group 3 (n = 8) was given 7.92 mg of levamisole/kg, and group 3 (n = 7) was given 11.88 mg of levamisole/kg. Efficacy against all worms was low in goats given 3.96 mg of levamisole/kg, but was high against adult H contortus (99%) and adult T colubriformis (99.7%) in goats given 7.92 mg of levamisole/kg. Although efficacy against adults of all species was high in goats given 11.88 mg of levamisole/kg, some immature worms of all species remained in the abomasa of goats. 相似文献