Integrated Parasite Management Research Articles

Integrated parasite management (IPM) and the pasture ecosystem: Optimizing outcomes for cattle, insect biodiversity, and soil health

Concerns over the negative environmental impacts of livestock parasiticide treatments and the widespread development of resistance has precipitated a move towards integrated parasite management (IPM). However, within the pasture ecosystem management strategies are likely to impact multiple processes in complex ways. This study investigates the impacts of IPM strategies on pest flies, gastrointestinal nematode (GIN) parasites, beneficial dung insects, and soil health. Twenty-nine grazing dairy farms participated in the study, representing different chemical and nonchemical parasite management and grazing strategies (continuous, rotational, or management intensive rotational (MIG)). Cattle managed using rotational grazing and MIG had significantly lower FEC than continuously grazed cattle. Farms using chemical parasiticides had significantly fewer pest flies, however farms releasing parasitoid wasps as biological control also had reduced abundances. Dung inhabiting beetle abundance was significantly correlated with reduced pest flies and GIN. Beneficial insects were negatively impacted on farms that used parasiticides. Continuously grazed pastures had higher beneficial insect abundances only on farms that did not use chemical parasiticides. Pastures managed under MIG had lower soil bulk density and higher active carbon compared to continuous grazing. There were positive associations between soil health and tunneling dung insects (Onthophagus spp. dung beetles). Finding optimal strategies will be context dependent, however the results of this study indicate that grazing strategies can control gastrointestinal parasites and improve soil health outcomes, natural enemies such as parasitoid wasps and dung inhabiting beetles can suppress pest fly populations, and the impacts of chemical control strategies may be mitigated through thoughtful implementation.

66 Effect of copper oxide wire particles on parasitism and growth in Katahdin lambs divergently selected for fecal egg count estimated breeding value

Abstract Internal parasites are one of the greatest threats to small ruminant production across the United States and parasitic resistance to anthelmintics continues to increase. Genetic selection and copper oxide wire particles (COWP) are two tools that could help reduce effects of parasites in small ruminants. The objective of this project was to determine the effects and interactions of COWP and genetic selection based on fecal egg count (FEC) estimated breeding value (EBV) on gastrointestinal nematode (GIN) infection and performance in naturally infected Katahdin lambs. Spring-born Katahdin ram lambs (n = 52) selected for extremely high FEC EBV (HighFEC, PFEC EBV = +100%) or low FEC EBV (LowFEC, PFEC EBV = -81%) were managed on a fescue-based pasture at the Southwest Virginia Agricultural Research and Extension Center (Glade Spring, VA). At weaning (June 29), lambs were dewormed with a three-combination treatment and rested for 21 d. At the start of the project (July 18), a random subset of lambs (HighFEC, n = 11; LowFEC, n = 15) were given a 2 g copper oxide wire particle bolus, while an equal number of remaining lambs were managed as controls without a copper bolus. All lambs were managed as one contemporary group. Fecal egg counts, FAMACHA scores, body weights, and packed cell volume (PCV) were measured bi-weekly for 10 weeks. Statistical analysis was performed using PROC Mixed Procedure of SAS (SAS Institute, Cary, NC) and FEC data were log transformed for normality. There were no effects of COWP treatment on FEC (P = 0.18). However, LowFEC-selected lambs had less FEC than HighFEC-selected lambs (230 vs. 565 eggs/g, respectively; P < 0.01). There was no interaction of COWP treatment and FEC genotype (P = 0.37). Copper oxide wire particle treatment had no effect on lamb body weight (P = 0.21), PCV (P = 0.69), FAMACHA score (P = 0.41), or overall ADG (P = 0.12). Lamb FEC genotype did not affect FAMACHA score or overall ADG (P = 0.10 and P = 0.22, respectively). LowFEC-selected lambs had lighter body weights (27.7 vs. 30.6 kg, respectively) and PCV (29.2% vs. 30.4%, respectively) than the HighFEC-selected lambs (P < 0.05). None of the 52 lambs met the requirement for deworming (FAMACHA ≥ 3) during the study. These results indicate that lamb FEC genotype may have a greater effect on parasitism than COWP treatment when given once during the post-weaning period. Even so, multiple tools should be considered, in addition to selection, for an integrated parasite management plan.

74 Effect of grazing native warm season grasses on parasitism and growth in weaned Katahdin lambs

Abstract Parasitism in lambs during the post-weaning period has effects on growth, survival, and sheep enterprise profitability. Opportunities to minimize exposure to infective larvae during this period may reduce clinical effects and improve lamb performance. Native warm season grasses (NWSG) offer increased growth during summer months and taller plants that allow grazing at greater heights. The objective here was to evaluate NWSG as a forage for post-weaning development of lambs in spring lambing, forage-based systems. Over 2 yr, Katahdin lambs (Yr 1, n = 30; Yr 2, n = 31) were managed at a producer farm in the piedmont region of North Carolina. Beginning 2 wk post-weaning, lambs were randomly assigned to graze on either NWSG (Big Bluestem and Indiangrass) or cool season grass (CSG, Kentucky 31 Tall Fescue base) pasture. Lambs were continuously grazed for 70 d in Yr 1 and 55 d in Yr 2. Fecal egg count (FEC), FAMACHA score, and body weight (BW) were measured every two weeks. Lambs were dewormed at FAMACHA ≥ 3. Forage analysis was conducted at the start and end of the grazing period. Statistical analysis were performance using the PROC Mixed procedure of SAS. Lambs in each group were raised in similar litter sizes and sire and sex were evenly distributed between groups. Fecal egg count and growth estimated breeding values (EBV) were similar between NWSG and CSG groups. In Yr 1 and 2, no differences were observed in FEC between grazing groups (P > 0.05). However, FEC did increase in both groups throughout the grazing period (P < 0.05). In Yr 1, no differences were observed in total BW gain (P = 0.74). However, in Yr 2, lambs grazing CSG had greater total BW gain than the NWSG group (P < 0.05). In both years, there were no differences in the percentage of lambs requiring deworming (Yr 1, P = 0.36; Yr 2, P = 0.47) but lambs requiring treatment had greater FEC EBVs (P < 0.05). Nutrient quality of NWSG pasture was reduced compared with CSG pastures. Total digestible nutrients and crude protein were less in NWSG compared with CSG pastures (Yr 2: 61.5% vs. 63.9% and 8.9% vs. 13.6%, respectively) and neutral detergent fiber was greater (Yr 2: 74.1% vs. 65.2%, respectively) resulting in decreased nutrient availability for NWSG group. While NWSG may provide additional biomass for summer grazing, rapid maturity rates may limit nutrient availability for lambs resulting in decreased growth performance despite similar levels of parasitism. Lamb FEC EBV may have a role in parasite resistance and deworming requirements regardless of forage type. Thus, genetics must be considered along with grazing management as part of an integrated parasite management plan.

Brazil's battle against Rhipicephalus (Boophilus) microplus ticks: current strategies and future directions.

Ticks are parasitic arthropods that cause significant economic losses to livestock production worldwide. Although Rhipicephalus (Boophilus) microplus, the cattle tick, occurs throughout the Brazilian territory, there is no official program to control this tick, which is the vector of tick fever pathogens. We address the situation of R. (B.) microplus resistance to synthetic acaricides in Brazil, including cattle tick management; the status of tick resistance per Brazilian state; the history of resistance occurrence of different acaricides; multiple resistance occurrence; and the main strategies for integrated tick management. Tick control in Brazil is characterized by management errors. Local laboratories affiliated with federal and state research institutions and universities employ the Adult Immersion Test as a primary diagnostic method to assess acaricide resistance to topically applied drugs. Only three states (Acre, Amapá, and Amazonas) have no reports on resistant populations. Misinformation on tick control strategies, misuse of available products for tick control, no adoption of Integrated Parasite Management (IPM) practices, low technical support to producers, and the high-speed emergence of acaricide-resistant tick populations are the main problems. We also propose a list of needs and priorities for cattle tick control regarding communication, research, and policies.

Parasite control in cattle is evolving

Increasing reports of anthelmintic resistance of gut and lungworm are occurring, probably because of over-treatment with the same products, often unnecessarily. A more sustainable approach to parasite control – known as integrated parasite management – puts diagnostic testing and prevention before treating, centre stage. This reduces farmers' reliance on products, saving them for when they might be really needed.

Integrated Parasite Management for Controlling Livestock Parasites

Integrated Parasite Management for Controlling Livestock Parasites

Environmental detection of Fasciola hepatica by loop-mediated isothermal amplification.

Fasciola hepatica, commonly referred to as liver flukes, is a substantial zoonotic parasitic disease of humans and livestock globally. While infection is readily controlled by anthelmintics, namely triclabendazole, the heavy reliance on triclabendazole has resulted in drug resistance appearing worldwide. Due to drug resistance, it is imperative to adopt an integrated parasite management program to preserve the efficacy of currently available anthelmintics. A integrated liver fluke management plan would benefit from a simple rapid, field-deployable diagnostic for detection of F. hepatica in environment and the host. Therefore, a rapid DNA test using loop-mediated isothermal amplification was developed and optimised for the detection of F. hepatica from faecal and water samples to enable the detection of parasites both within the host and from the environment. The assay presented here is fast, with amplification in ≤20 min, and highly sensitive, with a detection limit of 5 × 10−4 ng/µL. The workflow presented here provides a time to result of ≤60 min without requiring a commercial kit for the extraction of DNA from faecal and water samples, and pending further validation from field-samples, could potentially be used to enable real-time decision making to mitigate parasite prevalence on a farming property and with no requirement for sample transportation.

Grazier perceptions and management practices for liver fluke control in north eastern NSW, Australia.

A survey of livestock producers (graziers) located in north eastern NSW Australia, collected information on perceptions and management practices for liver fluke control in livestock. The total area farmed by the 161 respondents was 195,600ha (ranging in size from 4 to 10,522ha) with cattle and sheep being the dominant livestock enterprises. Overall, 80% of graziers relied exclusively on anthelmintics for liver fluke control and few of these graziers (9%) integrated parasite management (IPM) strategies to reduce disease prevalence. Of those relying on anthelmintic control, triclabendazole (TCBZ) was preferentially chosen by 75% of graziers. Fifty five percent of these graziers used TCBZ in combination with oxfendazole (46%), ivermectin (5%) or abamectin (4%) whilst 45% used TCBZ as a single active ingredient. Thirty eight percent of graziers drenched livestock one or more times per year for liver fluke despite claiming they had no liver fluke or confirmed knowledge of infection. Fifty one percent of graziers based anthelmintic dose on the known weight of the heaviest animal in the herd whilst 43% visually guessed livestock bodyweight to calculate anthelmintic dose. Choice of anthelmintic was predominately based on perceived efficacy (45%) despite very few graziers (2%) having conducted post-treatment fluke egg counts. The majority of graziers (76%) were unsure if they had anthelmintic resistance, 21% claimed they had no resistance whilst 3% of graziers had confirmed resistance. Most graziers (97%) also reported farms were cohabited by kangaroos highlighting additional grazing pressures on-farm. This current survey has revealed that graziers rely on anthelmintics as their primary choice for liver fluke control. Reluctance to adopt IPM strategies and a continued heavy reliance on TCBZ, whilst basing anthelmintic decisions on perception rather than measurement and testing, pose threats for the future control of liver fluke in livestock within this endemic area.

Approaches to Integrated Parasite Management (IPM) for Theileria orientalis with an Emphasis on Immunity.

Integrated parasite management (IPM) for pests, pathogens and parasites involves reducing or breaking transmission to reduce the impact of infection or infestation. For Theileria orientalis, the critical impact of infection is the first wave of parasitaemia from the virulent genotypes, Ikeda and Chitose, associated with the sequelae from the development of anaemia. Therefore, current control measures for T. orientalis advocate excluding the movement of naïve stock from non-endemic regions into infected areas and controlling the tick Haemaphysalis longicornis, the final host. In Australia, treatment of established infection is limited to supportive therapy. To update and expand these options, this review examines progress towards prevention and therapy for T. orientalis, which are key elements for inclusion in IPM measures to control this parasite.

Changing landscape of parasite control in small ruminants

Control of gastrointestinal (GIN) parasites is of primary concern in any small ruminant health management program, and is critical to profitability of the farm. For many years, GIN were controlled by the frequent use of anthelmintics, and this approach was quite effective. However, we now know that this strategy is shortsighted and unsustainable. Anthelmintic resistance is bounding out of control, and many of the drugs relied upon for decades no longer are effective on many farms. Furthermore, despite the occasional development of new anthelmintic classes, history clearly demonstrates that the development of resistance is almost certain to outpace the introduction of new drug classes. Thus, anthelmintics can no longer be viewed as inexpensive management tools, but instead must be viewed as extremely valuable and limited resources. Furthermore, parasite control must no longer be equated with a deworming program. Rather, parasite control will only be sustainable if it is approached as an integrated parasite management program, where anthelmintics are only 1 of several components. Additionally, there are new strategies for how we need to use our anthelmintics, the most important of which are that treatment is given selectively to animals based on need, and multiple anthelmintics are administered as a combination treatment.

THE IMPORTANCE OF DIFFERNTIAL DIAGNOSIS OF RESISTANCE AND RESILIENCE IN RUMINANTS

Control of the gastrointestinal parasites in different systems of ruminant breeding is based on vaccination, chemotherapy, improved herd management and use of genetic potentials of host animals. Strategy of the helminths control based on frequent anthelmintics usage is dominant among the world, although it is considered unsustainable due to the appearance of increased number and species of parasites that are resistance to drugs. Development of resistance on all three groups of broad-spectrum antihelmintics (nicotinic anthelmintics, benzimidazoles and macrolides lactones) as well as increased care for consumers heath caused by appearance of used drugs residues in food, additionally complicate overall nematode control. With the aim to decrease appearance of anthelmintics resistance of gastrointestinal nematodes of small ruminants and in order to organize process of sustainable integrated parasite management, principle of targeted selective treatment is globally accepted. Implementing of this strategy has only recently become feasible, with development and practical use of systems that serve for clinical assessment of anemia in small ruminants which suffer from hemonchosis. Besides that, short term changes in body weight and body condition scoring may be indicators of diseases caused by endoparasites, as it can provide rapid identification of animals that will probably have benefits from therapy. Obtained results of quantitative coprological diagnostic tests and results for anemia assessment are criteria that provide differential diagnosis between healthy and resilient animals and easier diseases diagnostic. Since resilient animals play important role in pasture contamination, the significance of their detection is understandable.

Wild horse populations in south-east Australia have a high prevalence of Strongylus vulgaris and may act as a reservoir of infection for domestic horses.

Australia has over 400,000 wild horses, the largest wild equid population in the world, scattered across a range of different habitats. We hypothesised that wild horse populations unexposed to anthelmintics would have a high prevalence of Strongylus vulgaris infections. Verminous endarteritis and colic due to migrating S. vulgaris larvae is now absent or unreported in domestic horses in Australia, yet wild horses may pose a risk for its re-emergence. A total of 289 faecal egg counts (FECs) were performed across six remote wild horse populations in south-east Australia, of varying densities, herd sizes and habitats. Total strongyle egg counts ranged from 50 to 3740 eggs per gram (EPG, mean 1443) and 89% (257/289) of faecal samples had > 500 EPG, classifying them as ‘high level shedders’. There were significant differences in mean total strongyle FECs between different locations, habitats and population densities. Occurrence of S. vulgaris was not predictable based on FECs of total strongyle eggs or small (<90 μm) strongyle eggs. A high prevalence of S. vulgaris DNA in faecal samples was demonstrated across all six populations, with an overall predicted prevalence of 96.7%. This finding is important, because of the ample opportunity for transmission to domestic horses. The high prevalence of S. vulgaris suggests vigilance is required when adopting wild horses, or when domestic horses graze in environments inhabited by wild horses. Appropriate veterinary advise is required to minimize disease risk due to S. vulgaris. Monitoring horses for S. vulgaris using larval culture or qPCR remains prudent. Gastrointestinal parasites in wild horse populations may also serve as parasite refugia, thus contributing to integrated parasite management when facing emerging anthelmintic resistance.

Nematophagous Activity of Duddingtonia Flagrans MUCL 9827 Against Sheep Gastrointestinal Nematodes

Summary Gastro-intestinal nematodes (GIN) of sheep are one of major constraints in grazing production systems worldwide. Control is commonly achieved using anthelmintics, but global occurrence of anthelmintic resistance to different drugs and the emergence of multi-resistant GIN species seriously limit the efficiency of their use. Therefore, integrated parasite management is widely recommended, with nematophagous fungi as one of control tools. Duddingtonia flagrans is one of the most used species, with various effect of different isolates. In previously performed coproculture assay, we showed low efficacy of D. flagrans MUCL 9827 against infective larvae (L3) of sheep GIN. The aim of current experiment was to reevaluate its nematophagous potential, using the medium where direct interaction between the fungus and L3 could be observed. Nematophagous activity was tested on 2% water agar with addition of chloramphenicol on three series of plates seeded with 500 and 1000 chlamidospores and agar blocks with 7 days old mycelium. At Days 0 and 5, 500 L3 of sheep GIN were added to test the trapping activity. The cultures, including control plates with only L3, were incubated at 25°C for 10 days, followed by evaluation of their number and reduction percentage. Nematophagous activity of D. flagrans MUCL 9827 against L3 was clearly demonstrated. However, the overall efficacy was poor since trapping was observed only in one out of nine plates containing fungal material. Potential reasons for such poor performance of the isolate of fungal species, otherwise known as successful in trapping animal parasitic nematodes, are discussed.

ANTHELMINTIC EFFECTS OF DRIED GROUND BANANA PLANT LEAVES (MUSA SPP.) FED TO SHEEP ARTIFICIALLY INFECTED WITH HAEMONCHUS CONTORTUS AND TRICHOSTRONGYLUS COLUBRIFORMIS

Background:Helminths is a endoparasites that cause the major losses for profitable sheep production in Brazil. The increased development of resistant strains of endoparasites have enforced the search for sustainable alternatives. The aim of this paper was to provide information about endoparasites control with banana leaves in infected sheep as alternative control strategies and see its viability.Materials and Methods:In this study, we performed two trials to investigate the anthelmintic properties of banana leaves on endoparasites in sheep. In Trial 1, twelve sheep were artificially infected with Trichostrongylus colubriformis; in Trial 2, eleven sheep were artificially infected with Haemonchus contortus. Clinical examinations, packed cell volume, total protein, faecal egg counts (FECs) and egg hatchability tests (EHTs) were performed. At the end of the trials, the sheep were humanely slaughtered, and total worm counts were performed.Results:In Trial 1 and 2, no significant FEC decreases were note but significant diference in EHTs were observed. Total worm counts, clinical and haematological parameters did not reveal significant changes between the treatment and control groups. These results suggest that feeding dried ground banana plant leaves to sheep may reduce the viability of Trichostrongylus colubriformis eggs, and this anthelmintic activity is potentially exploitable as part of an integrated parasite management programme.Conclusion:However, further investigation is needed to establish the optimal dosage, develop a convenient delivery form and confirm the economic feasibility of using banana plantation byproducts as feed for ruminant species.Abbreviations: Coproculture test (CT)., Faecal egg count (FEC)., Egg hatchability test (EHT)

Prevalence of anthelmintic resistance on sheep and goat farms in the mid-Atlantic region and comparison of in vivo and in vitro detection methods

Despite strong economic opportunities and incentives for small ruminant production, their health and productivity are often severely affected by parasitic disease. To combat these effects, most farms administer anthelmintics to their animals at frequent intervals, and without consideration to principles of sustainable integrated parasite management (SIPM). This has led to growing problems caused by the development of drug-resistant populations of gastrointestinal nematodes (GIN) in much of the world, particularly in Haemonchus contortus. The objectives of this research were to characterize levels of anthelmintic resistance on small ruminant farms located in the mid-Atlantic US and to compare the fecal egg count reduction test (FECRT) and larval development assay (LDA) for detecting resistance. To achieve these objectives, the DrenchRite® LDA was used to evaluate resistance status to benzimidazoles, ivermectin, moxidectin, and levamisole on 20 goat and 14 sheep farms in the Mid-Atlantic US over a 2-year period. A FECRT was also conducted on 14 of the same farms and on 2 additional farms in which the LDA was not completed. For the LDA and coprocultures, fecal samples were collected rectally from a minimum of 10 individual animals, pooled, and express-mailed to the University of Georgia for analysis. For the FECRT, albendazole, ivermectin, moxidectin, and/or levamisole were tested on each farm. Animals were allocated randomly based on FAMACHA© scores to 2–5 treatment groups, which included an untreated control group. The number of treatment groups on a farm depended on the number of qualified animals present. Haemonchus contortus was the most common parasite recovered from fecal cultures; the mean level across all farms was 79%. Results of the LDA indicated resistance to benzimidazoles, ivermectin, moxidectin, and levamisole on 100%, 82%, 47%, and 24% of farms, respectively. Multi-drug resistance to all 3 drug classes was detected for H. contortus on 18% of farms (1 sheep and 5 goat farms). Of the 16 farms tested by FECRT, resistance to albendazole was present on 8/10 farms, to ivermectin on 4/4 farms, to moxidectin on 7/9 farms and to levamisole on 2/5 farms tested. Results obtained from the FECRT and the LDA (p=0.51) were similar. The prevalence of resistance found in this study in the mid-Atlantic region of the US is very similar to that reported in an earlier survey of resistance performed in the Southern US, demonstrating that anthelmintic resistance in GIN is a serious problem on small ruminant farms throughout the Eastern US.

Integrated parasite management improves control of gastrointestinal nematodes in lamb production systems in a high summer-rainfall region, on the Northern Tablelands, New South Wales

This experiment tested the hypothesis that integrated parasite management (IPM) programs would reduce the effects of gastrointestinal nematodes (GIN) in meat-breed lamb production systems on the Northern Tablelands of New South Wales. The experiment was a longitudinal experiment using twin-bearing Border Leicester × Merino ewes on farms managed in accordance to either regional WormBoss IPM programs (n = 3 farms) or typical (TYP) regional GIN control (n = 2 farms). Ewes on each farm were either GIN-suppressed (SUP; n = 120 ewes) or not (NSUP; n = 120 ewes) and were managed in two groups (n = 120/group) balanced for GIN control. Ewes lambed in September and at lamb marking, 120 lambs (Dorset sires) from each ewe GIN control group were enrolled in the experiment to investigate the effect of ewe GIN control on lamb performance up to weaning. Overall mean worm egg count (WEC) of ewes (P = 0.004) was lower with IPM (IPM 766 vs TYP 931 epg) and was achieved with fewer drenches (IPM 4.5 vs TYP 5.5/year). Despite lower WEC, GIN infection reduced liveweight (IPM –2.1 kg vs TYP –1.1 kg, P = 0.0006) and clean fleece weight (IPM –0.11 kg vs TYP –0.01 kg, P = 0.03) of ewes to a greater extent on IPM farms. The annual rate of apparent ewe mortality was 6.5% and this was unaffected by GIN infection. WEC of lambs at weaning was lower on IPM farms (IPM 159 epg vs TYP 322, P &lt; 0.0001) but the difference in weaning weights of lambs reared by NSUP and SUP ewes was greater on IPM farms (IPM –1.1 kg vs TYP 0.2 kg, P &lt; 0.0001). Overall, the production loss due to GIN infection in these sheep-meat production systems, on the Northern Tablelands of New South Wales, was small and treatment frequency can be reduced by IPM programs.

Integrated parasite management with special reference to gastro-intestinal nematodes.

Domestic animals are susceptible to a large number of parasitic diseases, which lead to severe economic losses to livestock industry. So, it is necessary to control parasitic infections in these animals. Control of these helminths is undertaken mostly by anthelmintics, but because of their widespread use there is development of resistance across the globe. However, total dependence on a single method of control has proved to be non-sustainable and cost ineffective in the long term. A combination of treatment and management is necessary to control parasitism so that it will not cause further economic losses to producer as well as to livestock industry. To become practically and ecologically sustainable, parasitic control schemes need to be based on integrated parasite management.

Impact of integrated gastrointestinal nematode management training for U.S. goat and sheep producers

The objective of this study was to determine the impact of integrated parasite management (IPM) training, including FAMACHA© eyelid color scoring, on the ability of U.S. sheep and goat producers to control gastrointestinal nematodes (GIN) on their farms. A survey was developed and provided to over 2000 producers trained from 2004 to 2008 in IPM with questions involving farm size (number of sheep/goats), location (U.S. state), impact of training on parasite control efforts and parasite problems on farm, and IPM practices used. Responses were divided into U.S. Census regions of the U.S. Descriptive statistics and logistic regression were used to describe results. Most of the 729 respondents were from the southern region of the U.S. (54.3%) and were small-scale producers (50 or less animals; 64.8%). Nearly all of the respondents (95.1%) agreed that IPM workshop attendance made a difference in their ability to control and monitor parasitism in their herd or flock and employed IPM practices to control GIN (96.3%). The most popular practices respondents used were rotational grazing (71.2%), genetic selection (choosing a parasite resistant breed and/or culling susceptible animals; 52.7%), grain supplementation on pasture to improve nutrition (44.0%), and increased height of plants being grazed (41.8%). Although reporting using a practice decreased (P<0.05) the likelihood of reporting fewer problems, for each 1-point increase in the number of practices which producers employed to control internal parasitism in their herd or flock, they were 16% more likely to report fewer GIN problems (P<0.05). Approximately 75% of respondents indicated an economic benefit of IPM on their farm (P<0.05), and those reporting savings of over $80 were more likely to report fewer problems (P<0.05) with parasites after the training while those reporting no economic benefit were less likely to report fewer problems with GIN (P<0.001). Overall, IPM training resulted in positive impacts for producers responding to the survey and should continue.

Recommendations for control of gastrointestinal nematode parasites in small ruminants

Gastrointestinal nematode parasites are the single most important health problem of sheep and goats. Traditionally, parasites have been controlled by frequent administration of anthelmintic drugs. However, the emergence of multiple-drug-resistant parasites now threatens this paradigm of control and new approaches are required. Anthelmintics can no longer be thought of as a convenient and inexpensive management tool for maximizing animal productivity. Instead, anthelmintics must be thought of as extremely valuable and limited resources that should be used prudently. In response to this changing paradigm of anthelmintic use, new recommendations for parasite control now exist. A key tenet of this approach, referred to as "Smart Drenching", is to use the best available knowledge to develop strategies that maximize the effectiveness of treatments while also decreasing the development of drug resistance. Additionally, new innovative schemes using novel and sustainable approaches must be implemented. An overall strategy that integrates these approaches is referred to as "sustainable integrated parasite management" (sIPM). However, by its very nature sIPM is much more complicated and difficult to implement than casual administration of anthelmintics. Consequently, successful implementation of sIPM will only be possible with the help and active involvement of veterinarians and other animal health professionals. Because multiple-drug resistance in parasites is now the status quo, and development of further drug resistance is almost certain to outpace the development of new anthelmintics, it is critical that this new philosophy and approach to parasite control be embraced and implemented immediately.

Relevance of improved epidemiological knowledge to sustainable control ofHaemonchus contortusin Nigeria

Nigeria experiences losses in small ruminant production as a result of a high prevalence of infection with Haemonchus contortus, but there have been very few investigative studies into the epidemiology of H. contortus in Nigeria, particularly in the south and western parts of the country. For successful planning and execution of control of hemonchosis in Nigeria, there is a need for insight into the epidemiology of free-living stages under the prevailing local conditions and models for climatic and environmental factors that control the risk of hemonchosis and distribution of H. contortus. In this review, we assess previous studies on the epidemiology of H. contortus in Nigeria, evaluate the present climatic and epidemiological situation, and highlight areas that require further investigative studies. The goal is to identify factors that underpin better control strategies and holistic integrated farm-management practice. Previous studies on H. contortus provided important information for formulation of control strategies and development toward integrated parasite management. However, this review has revealed the need for holistic evaluation of the current epidemiology and prevalence of H. contortus in Nigeria, particularly in relation to climate change. Accurate information is needed to build useful predictive models of the population dynamics of all free-living stages, particularly the L3.