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The in vitro anthelmintic effect of the extracts on Haemonchus contortus (H. contortus) of three forage species in the tropical dry forest is known; however, there is no information about the effects of the extract partitions, nor their chemical composition. The objectives of this study were to evaluate the in vitro ovicidal activity of H. contortus in extract partitions of the species Gliricidia sepium, Leucaena leucocephala, and Pithecellobium dulce, and to identify the compounds present in the extract partitions with the highest activity by employing ultra HPLC Quadrupole orbitrap mass spectrometry. Four extract partitions, hexane, dichloromethane, ethyl acetate, and hydroethanolic from the three forage species were assessed in an inhibition of egg hatching (IEH) assay. The extract partitions with the highest anthelmintic activity (AA) were subjected to analysis, from which the tentative identification of the compounds was established. The extract partitions, including dichloromethane from Gliricidia sepium, ethyl acetate from Leucaena leucocephala, and hydroethanolic from Pithecellobium dulce showed a greater anthelmintic effect, with IC50 values of 0.39, 0.86, and 0.27 mg/mL for the IEH, respectively. Metabolites with in vitro AA potential included flavonoids, fatty acid esters, hydroxycinnamic acids, organic oxygenated compounds of the benzene class and substituted derivatives, phenolic glycosides, and phenols.

Gastrointestinal nematodes (GIN) use flexible life history strategies to maintain their fitness under environmental challenges. Costs incurred by a challenge to one life trait can be recouped by increasing the expression of subsequent life traits throughout their life cycle. Anticipating how parasites respond to the challenge of control interventions is critical for the long-term sustainability of the practice and to further ensure that the parasites withstand favourable adaptive responses. There is currently limited information on whether distinct populations of a GIN species respond to the same environmental challenge in a consistent manner, with similar alterations to their life history strategies or comparable fitness outcomes. This study compared the life history traits and experimental fitness of three distinct Haemonchus contortus isolates exposed to environmental challenges at both the parasitic (i.e., passage through resistant or susceptible sheep) and free-living (i.e., exposure to diverse climatic conditions) life stages. The key findings show that H. contortus maintain their fitness under challenge with isolate-specific alterations to their life history strategies. Further, partial exploration of the H. contortus isolates transcriptomes using cDNA-AFLP methods confirmed disparate expression profiles between them. These results bring fresh insights into our understanding of the non-genetic adaptive processes of GIN that may hinder the efficacy of parasite control strategies.

Background and Aim: Promotions of goat farming by both public and private sectors encouraged considerable goat raising in central Thailand. Gastrointestinal nematodes (GIN) infection is a major health and economic problem; however, evidence of resistance to broad-spectrum anthelmintics is frequently reported. Investigation of anthelmintic resistance (AR) status and identification of factors related to the development of AR is important components for sustainable GIN control. However, no information is available on this topic in the study area. The present study aimed to gather information on GIN control practices and to evaluate the effectiveness of albendazole, ivermectin, and levamisole for treating GIN infestation in goat herds in Sing Buri Province. Materials and Methods: Twenty-nine herds were randomly selected. Information on management practices was collected by face-to-face interview using a structured questionnaire. Three field experiments for routinely used anthelmintics, including albendazole, ivermectin, and levamisole were conducted from June 2019 to November 2019. Fecal samples were collected pre- and post-treatment and examined for fecal egg count reduction to determine the status of anthelmintic resistance of goat GIN. Results: Several improper practices were identified that lead to AR, especially chronic use of albendazole and ivermectin. All herds were considered resistant to albendazole and ivermectin, and levamisole resistant nematodes were detected in two herds. AR was strongly linked with the continuous use of anthelmintics. Conclusion: Levamisole, which was still effective in the province, should be used with caution to minimize the selection of resistant strains. Farmers should be provided with updated information for sustainable parasite control. Further, the efficacy of anthelmintics should be routinely monitored.

Rangelands are multi-use landscapes which are socially and ecologically important in different ways. Among other interactions, shared use of rangelands by wildlife and livestock can lead to disease transmission. Understanding wildlife and livestock health and managing disease transmission in rangelands requires an integration of social and ecological knowledge. Using the example of Western Kazakhstan, home to two types of ungulate hosts, the critically endangered saiga antelopes, Saiga tatarica, and livestock, we conducted a cross-scale analysis of social-economic, ecological and climatic factors that contribute to transmission of diseases We focused on gastrointestinal nematodes (GINs) because they are transmitted between hosts that share pasture and they affect ungulate fitness. We used an interdisciplinary social–ecological methods approach which included conducting faecal egg counts of GINs in saigas and livestock, semi-structured interviews and focus group discussions with livestock owners and herders in the region, and triangulation of information through secondary sources. Livestock rearing was done in two ways: (a) village-based livestock and (b) outlying farms. The latter overlapped more with saigas. Village-based livestock had significantly higher worm burdens than those on outlying farms, which had comparable burdens to saigas. Various factors exacerbate GIN prevalence and transmission: Veterinary services are minimal; both saiga and livestock numbers are increasing; and changing climate is increasing farmers' dependence on shared pastures for hay production. It will be crucial for saiga conservationists to engage in multi-pronged conservation interventions, which are evaluated and adapted through the lens of rural livelihoods and the livestock health on which they depend. Our work provides researchers and practitioners with an avenue to better understand complex inter-relationships and plan interventions within rangelands, while viewing host health from an interdisciplinary perspective—ultimately working towards wildlife conservation while safeguarding livelihoods across the world's rangelands. A free Plain Language Summary can be found within the Supporting Information of this article.

Gastrointestinal nematode (GIN) infections are one of the main health challenges in small ruminant and beef cattle systems, leading to reduced production and welfare globally. GIN are traditionally controlled with anthelmintic drugs, however due to regulations in organic farming systems and the rise in anthelmintic resistance, alternatives are sought after. One such alternative is the use of bioactive plant feeding, due to the presence of plant secondary (or specialised) metabolites (PSMs) that have been shown to demonstrate anthelmintic activity. This thesis focussed on the investigation of the anthelmintic activity of the perennial shrub heather (Ericaceae family) which is rich in PSMs, such as proanthocyanidins, and the plant is highly abundant across Europe indicating its amenability as an animal feed. The anthelmintic efficacy of heather extract was tested in vitro against Teladorsagia circumcincta and Trichostrongylus colubriformis eggs and infective larvae, as these species are two of the most prevalent small ruminant GIN in Europe. The efficacies of Calluna vulgaris extracts were compared across country of origin of the heather, the season in which the heather was sampled, and for Spanish samples, the efficacy of heather species was compared; C. vulgaris and Erica cinerea. To identify the key active compounds within the heather extracts, egg hatch assays were carried out using extracts incubated with polyvinyl polyrrolidone (PVPP), a chemical with the ability to block the activity of tannins and some galloylated flavonoids. The heather extracts were chemically analysed to quantify the relevant polyphenol subgroups present, and the chemical composition of the extracts was associated with the anthelmintic activity observed. This work provided in vitro evidence that heather has anthelmintic potential; the anthelmintic properties were characterised and quantified in vitro, and specific compounds identified that were associated with the anthelmintic effects on different GIN species and life stages. An in vivo study in domestic sheep (Ovis aries) was carried out using six groups of 10 Texel-cross lambs, grouped according to diet (heather or control hay), infection status (infected or uninfected) and the presence or absence of nematophagous fungi supplementation. In addition to the anthelmintic effects shown by PSM consumption, these compounds can also exhibit anti-nutritional effects within the animal. The aim of this study was to test the trade-off between the anti-nutritional and the curative effects of feeding heather to T. circumcincta infected lambs. As sustainable alternatives to anthelmintics are unlikely to be used in isolation, within this study we also tested the combination of feeding heather and a nematophagous fungi; Duddingtonia flagrans. It was observed that heather consumption at 20% of dry matter intake resulted in significantly lower egg output in infected lambs, although heather-fed lambs showed lower bodyweight compared to hay-fed lambs. Heather feeding had no impact on D. flagrans trapping ability, which indicates that these two alternatives could be used together to improve parasite control in animals. This work showed how heather feeding can exhibit anthelmintic effects, but care may be needed to reduce any anti-nutritional effects on performance. A systematic review was carried out to explore the anthelmintic efficacies shown by a wide range of bioactive plants, which contained polyphenolic compounds thought to be acting on GIN. The aim was to determine the considerations of using bioactive plant feeding as an effective and feasible alternative control method, and if in vitro testing is an accurate predictor of in vivo anthelmintic activity. The studies included in the systematic review had to fulfil the criteria: i) quantified the polyphenol content in the plants used, ii) measured bioactive plant intake by the study animals so the intake of polyphenols could be associated with any egg output reductions, and iii) all controls in place. The review highlighted a need for standardisation of protocols used to analyse polyphenol content of bioactive plants, to aid identification of effective doses and active compounds that should be focused on when selecting or breeding bioactive plants. Overall, the thesis demonstrated the potential of feeding bioactive plants such as heather to aid a reduction in anthelmintic drug use to control common parasite infections in livestock, and it explores which considerations are needed before farmers can maximise the efficacy of plants in the diet of ruminants.

This study examined the gastrointestinal parasitological status of three endangered Sub-Saharan antelope species (Addax nasomaculatus, Oryx dammah, Gazella dorcas) hosted at Souss-Massa National Park in Morocco. A total of 254 faecal samples (80 samples from the addax population, 81 from the oryx population and 93 from the dorcas population) were analysed to determine the prevalence and the intensity of the parasites in host faeces (expressed as the mean EPG: egg per gram), using microscopic methods (Flotation and McMaster) and the molecular identification of parasites using PCR and sequencing of the second internal transcribed spacer region of the rDNA (ITS-2).The prevalence results in the addax, oryx and dorcas gazelle were 43.7%, 2.4%, and 61.3%, respectively, for Nematodirus spp.; 21.2%, 12.3%, and 16.13%, respectively, for Trichuris spp.; and 36.2%, 39.5%, and 53.7%, respectively, for other, undistinguished strongylids.The means of EPG values for parasites in addax, oryx and dorcas gazelle were 8.9, 2.4, and 61.3, respectively, for Nematodirus spp.; 4.3, 2.4, and 4.8, respectively, for Trichuris spp.; and 18.1, 16.6, and 50.1, respectively, for other undistinguished strongylids. Sequencing of the ITS-2 rDNA region of the isolated parasites allowed the identification of Camelostrongylus mentulatus and Nematodirus spathiger in these three antelope species. We can U studiji je sprovedeno ispitivanje parazitološkog statusa intestinalnog trakta kod tri ugrožene vrste subsaharske antilope (Addax nasomaculatus, Oryx dammah, Gazella dorcas) koje su se nalazile u Souss-Massa nacionalnom parku u Maroku. Da bi se ispitala prevalencija i intenzitet infestacije parazitima kod životinja, ukupno je ispitano 254 uzoraka fecesa (80 uzoraka iz addax populacije, 81 uzoraka iz orix populacije i 93 uzoraka iz dorcas populacije) pri čemu su rezultati prikazivani kao srednja vrednost EPG (jajašca parazita po gramu fecesa). Korišćene su mikroskopske metode (Flotacija i McMaster) kao i molekularna identifi kacija parazita upotrebom PCR testa i sekvencioniranjem rDNK (ITS-2). Rezultati prevalence Nematodirus spp kod addax, oryx i dorcas gazela bili su: 43,7%, 2,4% odnosno 61,3%; za Trichuris spp vrste 21,2%, 12,3% i 16,3%, a za strongilidne vrste koje nisu mogle da se determinišu: 36,2%, 39,5% i 53,7%. Srednje EPG vrednosti za parazite kod adax, oryx i dorcas gazele bili su za Nematodirus spp vrste 8,9, 2,4 i 61,3; za Trichuris 4,3, 2,4 i 4,8 a za na strongilidne vrste koje nisu mogle da se determinišu, 18,1, 16,6 odnosno 50,1. Rezultati sekvencioniranja ITS-2 regiona rDNK izolovanih parazita omogućio je identifi kaciju Camelostrongylus mentulatus i Nematodirus spathinger u navedene tri vrste antilopa. Može da se zaključi da su infestacije parazitima kod ove tri vrste antilopa na podnošljivom nivou pri čemu je po prvi put dijagnostikovana infestacija antilopa u Maroku sa Camelostrongylus mentulatus i Nematodirus spathinger

Gastrointestinal nematode (GIN) parasites in grazing cattle are a major cause of production loss and their control is increasingly difficult due to anthelmintic resistance and climate change. Rotational grazing can support control and decrease reliance on chemical intervention, but is often complex due to the need to track grazing periods and infection levels, and the effect of weather on larval availability. In this paper, a simulation model was developed to predict the availability of infective larvae of the bovine GIN, Ostertagia ostertagi, at the level of individual pastures. The model was applied within a complex rotational grazing system and successfully reproduced observed variation in larval density between fields and over time. Four groups of cattle in their second grazing season (n = 44) were followed throughout the temperate grazing season with regular assessment of GIN faecal egg counts, which were dominated by O. ostertagi, animal weight and recording of field rotations. Each group of cattle was rotationally grazed on six group-specific fields throughout the 2019 grazing season. Maps and calendars were produced to illustrate the change in pasture infectivity (density of L3 on herbage) across the 24 separate grazing fields. Simulations predicted differences in pasture contamination levels in relation to the timing of grazing and the return period. A proportion of L3 was predicted to persist on herbage over winter, declining to similar intensities across fields before the start of the following grazing season, irrespective of contamination levels in the previous year. Model predictions showed good agreement with pasture larval counts. The model also simulated differences in seasonal pasture infectivity under rotational grazing in systems that differed in temperature and rainfall profiles. Further application could support individual farm decisions on evasive grazing and refugia management, and improved regional evaluation of optimal grazing strategies for parasite control. The integration of weather and livestock movement is inherent to the model, and facilitates consideration of climate change adaptation through improved disease control.

The objective of this study was to describe the serum protein pattern in sheep with naturally acquired gastrointestinal parasitosis and to compare the distribution of protein fractions with the results obtained in animals with negative fecal examination results. Fecal and blood samples were taken from twenty-nine sheep positive for nematode eggs and twenty-four animals with negative results of fecal examination. Between the evaluated groups of sheep significant differences were noted in the relative mean values for all protein fractions and for albumin/globulin ratio (p2-globulins and A/G ratio were significantly lower, the mean concentrations of α1-, β-, γ1- and γ2-globulins significantly higher in the nematode positive group of sheep (p2-zone in three sheep and the γ-globulin zones were characterized by a diffuse higher broad and wide peaks. The presented results indicate that the gastrointestinal parasitic infections in sheep alter the distribution of serum proteins, and suggest their usefulness in animals with unchanged serum protein concentrations. The study brings new findings and extends the knowledge about the metabolic responses and consequences of gastrointestinal parasitic infections in sheep, particularly with regard to alterations in protein metabolism.

This study aimed to evaluate the efficiency of the powdered formulation with the nematophagous fungi Duddingtonia flagrans against gastrointestinal nematodes of sheep under three feeding systems in...

This paper reports the use of near infrared and mid-infrared spectroscopy to detect the presence and quantity of eggs of the gastrointestinal nematode Haemonchus contortus in sheep faeces. Haemonchus contortus eggs were quantified in dried, finely ground sheep faeces and in moist, coarsely ground faeces using near infrared and mid-infrared bench top spectrometers and a portable near infrared spectrometer. When Haemonchus contortus eggs were presented without faecal medium, it was found that the wavelength region of 1880–2100 nm was most important for detection. Broad classes of chemical properties found in the near infrared region were identified for dried Haemonchus contortus eggs using a mid-infrared spectrometer. However, when Haemonchus contortus eggs were mixed into the complex matrix of sheep faeces, the development of a robust calibration model for egg detection proved to be challenging (R2

Gastrointestinal nematode (GIN) infestations are a major constraint to sheep production in the West Indies (WI). Intensive and semi-intensive management systems are most commonly employed. These islands display tropical weather patterns with wet and dry seasons. Semi-intensive farming combined with increased rainfall during the wet season has been reported to be most favourable for development and survival of GIN. This study was conducted to determine whether there was a relationship between GIN burdens in sheep with seasonality and management practices of farmers in Trinidad and Tobago (T&T). Farms were visited on a monthly basis from January to December 2017. A maximum of ten sheep, three to nine months of age, were selected from each farm. A total of 3,053 faecal samples were collected and analysed using the Modified McMaster technique. Environmental data on daily precipitation and temperature were collected from the Trinidad and Tobago Meteorological Office during the period of sampling. A mixed effects negative binomial regression model was constructed to analyse the relationship between gastrointestinal nematode faecal egg counts (GINFEC) with season, management system and use of dewormers as fixed effects and farm as a random effect. Average diurnal temperatures of T&T fluctuated between 23.2°C to 32.6°C and 23.9°C to 32.3°C in the dry and wet seasons, respectively. Average daily precipitation ranged between 1.6-1.8 mm and 6.1-8.5 mm during the dry and wet seasons, respectively. A decreased risk of 0.34 (95% CI 0.25-0.47, p

Simple Summary Gastrointestinal nematodes are included worldwide among the most prominent parasites of small ruminants. In past decades, the control of these nematodes mainly relied on the use of synthetic anthelmintic drugs. However, nowadays the exclusive use of anthelmintic drugs is considered an obsolete and unsustainable control strategy due to the onset of anthelmintic-resistant sheep gastrointestinal nematode strains and the issues linked with the environmental pollution and residues in food of animal origin of synthetic anthelmintic drugs. Among alternative or complementary methods, the use of plants endowed with anthelmintic properties has been identified as a valuable option. As a part of this approach, this study evaluated the in vitro anthelmintic properties of two commercial sea buckthorn (Hippophae rhamnoides) berry juices on sheep gastrointestinal nematodes. Both H. rhamnoides berry juices tested in this study showed interesting anthelmintic properties in vitro. The obtained results are promising regarding the use of sea buckthorn berry juice as a potential tool for the control of gastrointestinal nematodes in small ruminants. Gastrointestinal nematodes are one of the major threats in small ruminant breeding. Their control is difficult due to the development of anthelmintic resistance, and the search for new molecules endowed with anthelmintic activity (AH) is considered a priority. In this context, we evaluated the in vitro AH activity of two commercial sea buckthorn (Hippophae rhamnoides) berry juices, namely SBT and SBF. The in vitro evaluation was based on the egg-hatch test and larval exsheathment assay at different concentrations. Data were statistically analysed, and the EC50 was calculated. Chemical analyses were performed to evaluate the total polyphenol content of the juices and chemical profile of the most represented compounds. The role of the polyphenolic fraction in the anthelmintic activity of the juices was also assessed. At the highest concentrations, the activity of SBT was high in both tests and comparable to that observed in the thiabendazole-treated positive controls, while SBF showed a lower efficacy. Glycosylated isorhamnetin and quercetin were the most represented polyphenolic compounds in both juices. In conclusion, both H. rhamnoides berry juices tested in this study showed interesting anthelmintic properties in vitro.

Sheep gastrointestinal nematode (GIN) infestation represents a limiting factor for sheep farming and milk production in Italy. The development of anthelmintic resistance to conventionally used drugs suggests the path towards the use of natural remedies as a possible alternative. The purpose of this study is to evaluate the in vitro anthelmintic efficacy of the hydroalcoholic extracts of basal leaves (It-BL), cauline leaves (It-CL) and flowers (It-F) of Isatis tinctoria (Brassicaceae), a spontaneous Sicilian species renowned as an important source of bioactive compounds. The dry extracts of the different parts of the plant were tested using the egg hatch test (EHT) in vitro to verify the efficacy against ovine GIN at different concentrations (1.00, 0.5, 0.25, 0.125 mg/mL). Thiabendazole and deionized water were used as positive and negative controls, respectively. The results obtained from EHT indicated that all the I. tinctoria extracts were highly effective (p < 0.0001) in inhibiting egg hatching within 48 h of exposure. The in vitro inhibitory effect was never less than 84% in all doses tested, and it was only slightly lower than the standard drug thiabendazole (95.6%). The current study documents the anthelmintic activity of I. tinctoria against sheep’s GIN, suggesting its application as alternative natural method to limit the use of antiparasitic drugs.

Herbal products such as essential oils may play a promising role in the treatment of infections caused by gastrointestinal nematodes (GINs). The aim of this study was to evaluate the in vitro potential of 11 essential oils (EOs) and one binary combination of isolated EO compounds, as well as the in vivo anthelmintic efficacy of two EO formulations. Four GIN genera were identified in the coproculture examination: Haemonchus, Trichostrongylus, Teladorsagia and Chabertia. The in vitro egg hatch test (EHT) was performed at six different concentrations (50, 12.5, 3.125, 0.781, 0.195 and 0.049 mg/mL) for each EO, whereas in the in vivo faecal egg count reduction test (FECRT), each EO sample was diluted in sunflower oil and orally administrated at a dose of 100 mg/kg to the different group of animals. In the EHT, the EOs of Origanum vulgare, Foeniculum vulgare, Satureja montana, Satureja hortensis and two types of Thymus vulgaris were the most effective. The dominant compounds of these EOs were carvacrol, thymol, anethol, p-cymene and γ-terpinene, indicating their importance for the anthelmintic activity. In the FECRT, both T. vulgaris EO type 1 and linalool:estragole combination show an anthelmintic potential with a mean effect on FECR of approximately 25%. The results suggest the possible role of tested EOs as anthelmintic agents in sheep farms, although further in vivo tests are needed. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.

The development of anthelmintic resistance in sheep gastrointestinal nematodes (GINs) requires novel strategies for the sustainable control of these parasites. This study aimed to evaluate the anthelmintic efficacy of the Origanum vulgare (L.) essential oil (EO) against sheep GINs and to evaluate the possibility of its use in control practice. The in vitro egg hatch test was conducted at eight different concentrations (50, 12.5, 3.125, 0.781, 0.195, 0.049, 0.025, and 0.0125 mg/mL) of the tested EO. For the in vivo fecal egg count reduction test, the EO of O. vulgare was administrated orally at a mean single dose of 150 mg/kg to sheep from two farms in Southern Italy, whereby potential toxic effects to the hosts were also evaluated. In the egg hatch test, the inhibition of egg hatchability varied from 71.3% to 93.7%, depending on the concentration used. The high anthelmintic potential was confirmed in the fecal egg count reduction test with an average reduction of nematode eggs in feces of 43.2% and 60.1% on days 7 and 14 after treatment, respectively. In addition, no toxic effects were noticed during the clinical examination of sheep or by observing blood count and liver or kidney function test results. The obtained results suggest the strong activity of the O. vulgare EO against sheep GINs, probably due to a high percentage of carvacrol (76.21%), whereby it can be considered safe for sheep at the dose tested in vivo. Therefore, it is suitable for use in veterinary practice as a part of an integrated strategy for the control of sheep GINs.

Zeolite as a dietary supplement can improve animal resistance and resilience against gastrointestinal parasites. The effects of different levels of zeolite supplementation on gastrointestinal nematode infection, growth performance, and economic viability of male and female Santa Ines lambs were investigated. Four zeolite levels (0, 25, 50, and 75 g per day) were fed to 110 day-old animals in a randomized block experimental design. Eggs per gram of feces (EPG), total serum protein (TSP), and packed cell volume (PCV) were measured individually every week. The animals were weighed every 14 days and coprocultures were prepared. Male animals that reached an average live weight of 34 kg were harvested. The economic viability analysis of the experimental diets was based on feedlot periods of 56 and 91 days. Dietary supplementation with zeolite did not significantly mitigate infections by nematodes and did not affect TSP, PCV, or feedlot lamb growth performance. Therefore, zeolite was not an effective (P > 0.05) dietary supplement for avoiding gastrointestinal nematode infection or improving growth performance. Male animals slaughtered after 56 days of feeding were more economically viable (P < 0.05) than those slaughtered after 91 days. Feedlotting demonstrated that male animals had superior performance (P < 0.05) and better economic (P < 0.05) results than female animals. RESUMO O uso de zeólita na suplementação alimentar pode melhorar a resistência e resiliência aos parasitas gastrintestinal. Os efeitos da suplementação nutricional com zeólita de cordeiros Santa Inês no desempenho, crescimento, infecção por nematoides gastrintestinais e análise econômica foram investigados. Animais fêmeas e machos de 110 dias foram suplementados com quatro níveis de zeólita: 0, 25, 50, e 75 gramas por dia em um delineamento experimental em blocos ao acaso. Os ovos por grama de fezes (OPG), proteína sérica total (PST) e volume globular (VG) foram obtidos de cada animal semanalmente. A cada 14 dias os animais foram pesados e as coproculturas preparadas. Foram abatidos os machos que atingiram peso vivo médio de 34 kg. A análise de viabilidade econômica das dietas foi baseada nos períodos de confinamento de 56 e 91 dias. A zeólita não mitigou significativamente (P > 0,05) a infecção por nematoides, não afetou a PST, o PCV e o desempenho dos cordeiros confinados. A zeólita não foi um suplemento dietético eficiente para evitar a infecção por nematoides gastrintestinais ou melhorar o desempenho dos cordeiros. Os machos abatidos aos 56 dias de confinamento apresentaram maior viabilidade econômica (P < 0,05) comparados àqueles abatidos aos 91 dias. Os machos confinados tiveram desempenho superior (P < 0,05) e melhores resultados econômicos (P < 0,05) comparados às fêmeas. O aumento do período de confinamento reduziu a lucratividade.

Haemonchus contortus is an infectious gastrointestinal nematode parasite of small ruminants. This study addresses the in vitro/in vivo anti-haemonchiasis potential, toxicological effects, and mechanism of action of nanoparticles. Online databases were used to search and retrieve the published literature (2000 to 2021). A total of 18 articles were selected and reviewed, out of which, 13 (72.2%) studies reported in vitro, 9 (50.0%) in vivo, and 4 (22.2%) both in vitro/in vivo efficacy of different nanoparticles. Mostly, organic nanoparticles (77.7%) were used including polymeric (85.7%) and lipid nanoparticles (14.3%). The highest efficacy, in vitro, of 100% resulted from using encapsulated bromelain against eggs, larvae, and adult worm mortality at 4, 2, and 1 mg/ml, respectively. While in vivo, encapsulated Eucalyptus staigeriana oil reduced worm burden by 83.75% and encapsulated Cymbopogon citratus nano-emulsion by 83.1%. Encapsulated bromelain, encapsulated Eucalyptus staigeriana oil, and encapsulated Cymbopogon citratus nano-emulsion were safe and non-toxic in vivo. Encapsulated bromelain damaged the cuticle, caused paralysis, and death. Nanoparticles could be a potential source for developing novel anthelmintic drugs to overcome the emerging issue of anthelmintic resistance in H. contortus. Studies on molecular effects, toxicological consequences, and different pharmacological targets of nanoparticles are required in future research.

Gastrointestinal nematode infection is one of the major production problems for sheep producers worldwide due its high incidence, morbidity, and mortality in affected flocks. The study of long non-coding RNA (lncRNA) in liver tissue of high (HIR) and low immune responder (LIR) sheep to GINs using RNA-Sequencing technology may provide a better understanding of the gene regulation mechanism associated with the host response to the infection. The aim of this study was to identify differentially expressed (DE) lncRNA between HIR and LIR natural infested sheep and control group. Liver tissue samples from the 13 divergent animals (out of a population of 211) based on their immunoglobulin G levels after vaccination using Hen Egg White (HEW) Lysozyme, and immature abomasum worm counts [HIR (> 4000) (n = 5), LIR (< 1500) (n=5) and control (no parasite challenge) (n=4) groups] were used to perform transcriptomic analysis using RNA-Sequencing. The “Large Gap read mapping “and “Transcript Discovery” tools from CLC Genomics Workbench 20.0.4 (CLC Bio, Aarhus, Denmark), were used to map reads to a reference genome (Oar_rambouillet_v1.0) and transcript discovery, respectively. The FEELnc software was used to identify, from predicted transcript model, potential lncRNAs and classify those transcripts into intro putative lncRNAs and protein coding RNAs. As preliminary results, 8 and 48 DE lncRNAs for HIR and LIR compared to control group were identified, respectively using an adjusted p-value False Discovery Rate (FDR) < 0.05 and Fold change (FC) abs > 2. Functional analyses using the list of DE lncRNAs identified metabolic pathways related to immune function. In depth analysis will help to better understand the physiological mechanisms of resilience of high immune sheep.

5 páginas, 1 figura., This study was funded by the Spanish “Ramón y Cajal” Programme of the Ministry of Economy and Competitiveness (MMV, RYC-2015-18368), and the Cooperativa Bajo Duero, COBADU. None of the authors have a conflict of interest.

Resistance to anthelmintic drugs in gastrointestinal nematodes (GIN) of sheep is of high concern for livestock production worldwide. In Calabria (southern Italy), many plants have been used in ethnoveterinary medicine for parasite control in small ruminants. Here, we present an in vivo evaluation of anthelmintic efficacy of three plant extracts. The first was based on bark and leaves of Salix caprea, the second and the third were based on the whole plant Artemisia campestris and whole fruit (seeds and peel) of Punica granatum, respectively. Anthelmintic efficacy was evaluated according to the fecal egg count reduction test (FECRT) performed with the FLOTAC technique. The results showed a significant anthelmintic effect of Punica granatum macerate (50%), a low effectiveness of the Artemisia campestris macerate (20%), and a complete ineffectiveness of Salix caprea macerate (0.1%). With these outcomes, we report a P. granatum-based remedy reducing 50% GIN egg output. This result was obtained without using any synthetic drug, paving the way for the employment of green veterinary pharmacology (GVP) as a complementary and sustainable method to reduce the use of chemicals and to counteract anthelmintic resistance.

Tesis para obtener el grado de Magister en Sanidad Animal, Área de Producción y Sanidad Animal presentada en la Universidad Nacional de Mar del Plata, en septiembre 2021 En el estudio de la epidemiologia de los nematodos gastrointestinales (NGI), el conocimiento adecuado de los estadios de vida libre de estos es una de las claves más importantes para diseñar con un carácter racional programas de control sustentables. Una característica de relevancia epidemiológica es el clima, en la región del NOA se caracteriza climáticamente por tener un periodo de lluvias estivales seguido de una época de sequía invernal. En cuanto al estudio de la dinámica de dichos estadios, esta región carece de estudios en este aspecto. Por lo tanto, la información recolectada en el presente trabajo, aportará datos de relevancia para el manejo sustentable del parasitismo gastrointestinal y servirá de base para futuras investigaciones en la región. El objetivo general de este trabajo fue determinar la contribución estacional hecha por los huevos de NGI depositados en la materia fecal (MF) por bovinos naturalmente infestados y determinar el desarrollo, supervivencia de estos en la MF, migración hacia el pasto y supervivencia en este, en el Valle de Lerma, provincia de Salta. Se realizaron 5 deposiciones de MF con 4 repeticiones en parcelas experimentales cada una en los meses julio, octubre, diciembre, febrero y abril. Cada unidad de deposición fue uniformada en moldes de 800 g de MF. El 1er muestreo (5 g MF) se realizó a partir del 10° día poscontaminación para determinar el desarrollo de huevo a larva infectante (L3), el cual continuó cada 3 días hasta el hallazgo de L3. Posteriormente el muestreo se realizó de forma mensual hasta obtener dos resultados negativos consecutivos. El muestreo de pasto comenzó tres días posteriores al hallazgo de L3 en la MF, prolongándose mensualmente hasta obtener dos ressltados negativos. Se evaluó: tiempo de desarrollo (TA) tasa de desarrollo (TDF) de huevo a L3, tiempo de permanencia de L3 en materia fecal (TPMF) y tiempo de aparición (TAP), tasa de migración (TM) y tiempo de permanencia (TPP) de L3 en el pasto. Los principales géneros de parásitos presentes fueron Cooperia, Haemonchus y Oesophagostomum, los cuales fueron observados en todos los periodos en estudio. Los géneros Ostertagia y Trichostrongylus no fueron recuperados en los depósitos de octubre y diciembre. Se observaron diferencias significativas en el TA entre periodos (p

Background The diagnosis of gastrointestinal nematode (GIN) infections in ruminants is routinely based on morphological/morphometric analysis of parasite specimens recovered by coprological methods, followed by larval culture (LC) techniques. Such an approach is laborious, time-consuming, requires a skilled expert, and moreover suffers from certain limitations. Molecular tools are able to overcome the majority of these issues, providing accurate identification of nematode species and, therefore, may be valuable in sustainable parasite control strategies. Methods Two multiplex real-time polymerase chain reaction (PCR) assays for specific detection of five main and one invasive GIN species, including an internal amplification control to avoid false-negative results, were designed targeting SSU rRNA and COI genetic markers, as well as established ITS1/2 sequences. The assays were optimized for analysis of DNA extracted directly from sheep faeces and verified for Haemonchus contortus, Teladorsagia circumcincta, Trichostrongylus colubriformis, Nematodirus battus, Chabertia ovina, and Ashworthius sidemi. Semi-quantitative evaluation of infection intensity was enabled using a plasmid construct and a dilution series of sheep faeces with a known number of nematode eggs. Assays were tested on 44 individually collected faecal samples from three farms, and results were compared to those from faecal egg counts (FEC) using the concentration McMaster technique and LC. Results Multiplex real-time PCR assays showed great specificity to target nematodes. During the analysis of faecal samples, the assays proved to have higher sensitivity in strongylid-type egg detection over FEC by revealing three false-negative samples, while showing moderate agreement in evaluation of infection intensity. The multiplex assays further clarified GIN species identification compared to LC, which had confused determination of Teladorsagia spp. for Trichostrongylus spp. Conclusions Our multiplex assays proved to be a rapid and accurate approach enabling simultaneous and reliable GIN species identification from faeces and semi-quantitative estimation of the number of eggs present. This approach increases diagnostic value and may add a high degree of precision to evaluation of anthelmintic efficacy, where it is important to identify species surviving after treatment. Graphical Abstract

This review article provides an historical perspective on some of the major research advances of relevance to ruminant livestock gastrointestinal nematode control over the last 50 years. Over this period, gastrointestinal nematode control has been dominated by the use of broad-spectrum anthelmintic drugs. Whilst this has provided unprecedented levels of successful control for many years, this approach has been gradually breaking down for more than two decades and is increasingly unsustainable which is due, at least in part, to the emergence of anthelmintic drug resistance and a number of other factors discussed in this article. We first cover the remarkable success story of the discovery and development of broad-spectrum anthelmintic drugs, the changing face of anthelmintic drug discovery research and the emergence of anthelmintic resistance. This is followed by a review of some of the major advances in the increasingly important area of non-pharmaceutical gastrointestinal nematode control including immunology and vaccine development, epidemiological modelling and some of the alternative control strategies such as breeding for host resistance, refugia-based methods and biological control. The last 50 years have witnessed remarkable innovation and success in research aiming to improve ruminant livestock gastrointestinal nematode control, particularly given the relatively small size of the research community and limited funding. In spite of this, the growing global demand for livestock products, together with the need to maximise production efficiencies, reduce environmental impacts and safeguard animal welfare – as well as specific challenges such as anthelmintic drug resistance and climate change– mean that gastrointestinal nematode researchers will need to be as innovative in the next 50 years as in the last.

Made available in DSpace on 2021-06-25T11:14:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-07-01 The synthesis of thiophenic compounds, previously identified in Tagetes patula, revealed that 4-(5′-(hydroxymethyl)-[2,2′-bithiophene]-5-yl)but-3-yn-1-ol), or simply Thio1, has a pronounced in vitro anthelmintic effect against Haemonchus contortus, showing 100% efficacy in the egg hatch and larval development tests presenting EC50 = 0.1731 mg.mL−1 and EC50 = 0.3243 mg.mL−1, respectively. So, this compound was selected to preparation of a nanostructured formulation to be orally administered to Santa Inês sheep. In general, from the fecal egg count reduction test (FECRT), it was observed that the product kept the parasitic load in the digestive tract of the hosts stable, with eggs per gram of faeces (EPG) counts having a mean value < 3,000 (EPGmean = 2167.1, efficacy = 36,45%), thus protecting the animals from health risks caused by a massive nematode infestation. To better understand the mode of action of this thiophene derivative, in silico molecular modeling studies were carried out with the glutamate-activated chloride channel (GluCl), a well-known molecular target of anthelmintic compounds. Based on the affinity score (GlideScore = -5.7 kcal.mol−1) and the proposed binding mode, Thio1 could be classified as a potential GluCl ligand, justifying the promising results observed in the anthelmintic assays. School of Pharmaceutical Sciences São Paulo State University (UNESP) University of São Paulo (USP) Physics Institute of São Carlos (IFSC) University of Campinas (UNICAMP) Chemistry Institute College of Pharmacy Dentistry and Nursing Federal University of Ceará (UFC) Brazilian Agricultural Research Corporation (EMBRAPA) Southeast Livestock Chemistry Institute São Paulo State University (UNESP) School of Pharmaceutical Sciences São Paulo State University (UNESP) Chemistry Institute São Paulo State University (UNESP)

The objective was to examine GIN infection and BW of lambs born in fall (Oct–Nov; n = 20–158/yr; n = 716 total) or winter (Jan–Feb; n = 65–208/yr; n = 1717 total). Katahdin lambs born between 2008 and 2020 were weaned between 90–120 d of age and supplemented with a 15% CP grain mix when forage quality was low. Dams were supplemented up to 30 d before to 60 d post-lambing. BW and FAMACHA scores were determined at approximately 60, 90, 120, and 150 d of age; FEC and PCV were determined at approximately 90, 120, and 150 d of age. Lambs were dewormed if FAMACHA score was > 3. Data were analyzed using mixed models with a repeated statement for day of sample collection, and age within season-yr used as a covariate. Season × yr × day influenced all traits (P < 0.001); litter number, sex, age of dam influenced BW (P < 0.001). FEC were higher in fall than winter born lambs only on d 90, and similar on d 120 and 150 (P < 0.001). PCV was lower in winter than fall born lambs on d 120 and 150 (P < 0.001), and FAMACHA lower on all days measured in fall than winter lambs (P < 0.001) making the winter born more susceptible to anemia with a greater need for deworming. Haemonchus contortus was the predominant GIN on most days of culture for both seasons. Fall compared with winter lambs were lighter in BW at all time points (P < 0.001) possibly due to poor forage quality available to dams. Rainfall data will be presented. GIN control was more manageable in fall than winter born lambs, but they weighed less.

The aim of this work was to study the etiology and epidemiology of gastrointestinal nematodes (GIN) of goat from the Arid valleys and canyons (AVC), Tempered valleys (TV) and the Semiarid Chaco (SC) regions of northwestern Argentina. Ten flocks were studied and 35 to 40 goats per flock (total= 420 goats) were fecal matter sampled each 30-40 days. Individual eggs per gram of faeces (epg) and faeces cultures were performed. Differences among epg were compared using Kruskal–Wallis non-parametric test. The epg of the three regions showed the same trend: an increment from February reaching the highest average epg peak in April-May and then a fall ​​towards the summer. Goat flocks of TV region showed the highest epg compared to the other two regions, which generally showed low epg values. Haemonchus sp. and Trichostrongylus spp. were the predominant nematode genera recovered in the three regions, although in a smaller proportion Teladorsagia, Oesophagostomum, Nematodirus, Trichuris, Skrjabinema and Strongyloides genera were also recovered. These results show that GIN would be a limiting factor of caprine production in the TV and only during critical periods and under some breeding systems in the other regions. Instituto de Investigación Animal del Chaco Semiárido Fil: Suarez, Victor Humberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Investigación Animal del Chaco Semiárido. Área de Investigación en Salud Animal; Argentina Fil: Martinez, Gabriela Marcela. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Salta; Argentina Fil: Olmos, Leandro Hipolito. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Investigación Animal del Chaco Semiárido. Área de Investigación en Salud Animal; Argentina

Small ruminants are very affected by gastrointestinal nematode (GIN) parasitism worldwide. The improvement of the host protective response and the reduction of the probability of contact between hosts and parasites appear as very promising strategies. The objective of this study was to evaluate the effect of a combination of two components of these two strategies on natural GIN infection and production performances of Creole goat kids: dietary supplementation and a rotational mixed grazing system. One hundred and twenty weaned Creole kids and six Creole heifers were divided into four experimental batches: Splus (supplemented) vs. Szero (non-supplemented) × Mixed grazing (kids associated with heifers) vs. Control (kids alone), and grazing plots of forage grasses were balanced for live weight (LW) in both species. The feed intake, blood, and parasitological parameters and production performances between 3 and 11 months of age were monitored. The fecal egg count (FEC) was significantly lower and the packed cell volume (PCV) significantly higher in the Mixed grazing groups. No effect of supplementation was observed for FEC. In contrast, PCV, body condition score, and live weight were significantly higher in supplemented animals whatever the groups. Mixed grazing system and supplementation had significant effects on the slaughter parameters (P < 0.05), but there was no significant interaction. Our results suggested that the advantage driven either by mixed grazing or dietary supplementation on kids' performances would be equivalent, and the combination of both would improve the animal performances.

Given the economic impact of gastrointestinal nematode infection on livestock farming worldwide, and increasing anthelmintic resistance, it is imperative to develop practical, efficient and sustainable control strategies. Targeted selective treatment (TST), whereby anthelmintic treatments are administered to animals individually, based on selection criteria such as weight gain, has been shown to successfully maintain animal productivity whilst reducing the selection pressure for anthelmintic resistance and the economic cost of treatment in experimental and commercial settings. Despite the benefits of the TST approach, the equipment and time required to monitor animals individually make this strategy unsuitable for some farming enterprises. The sentinel group approach aims to maintain the benefits observed using TST whilst reducing these requirements. The study involved two experiments, each following a group of 80 lambs through their first grazing season. Anthelmintic treatment of the whole group was determined by monitoring the weight gain of identified sentinel lambs within it every 2 weeks: when 40% of the sentinel lambs failed to reach their weight gain targets, the whole group was treated. The sentinel lambs consisted of 45% of the group (n = 36) in experiment one and 20% (n = 16) in experiment two. A control group of 20 lambs was co-grazed with the main group during both experiments; in experiment one, the sentinel approach was compared with a TST approach, in which control lambs were treated on an individual basis in response to weight gain. In experiment two, the sentinel approach was compared with conventional prophylaxis, where all lambs in the control group were treated at strategic time points throughout the season (= strategic prophylactic treatment). The sentinel lambs were found to be representative of overall group performance regardless of the proportion of sentinels within the group: they recorded similar growth rates and reached weight gain targets simultaneously at each time point and overall. Live-weight gain was also similar between sentinel and control animals in both experiments. The findings of the current study suggest that monitoring sentinel lambs comprising 20% of a group of grazing lambs is sufficient to determine the need for anthelmintic treatment within the whole group, and that this approach maintains production in line with conventional or TST treatment regimes.

Anthelmintic resistance threatens the sustainability of sheep production globally. Advice regarding strategies to reduce the development of anthelmintic resistance incorporates the outcomes of modelling exercises. Further understanding of gastrointestinal nematode species diversity, and population dynamics and genetics (which may vary between species) is required to refine these models; and field studies combining faecal egg outputs, species composition and resistance genetics are needed to calibrate them. In this study, faecal samples were taken from ewes and lambs on a commercial farm in south-eastern Scotland at approximately 3 t-4 week intervals between spring and autumn over a period of 4 years. Faecal egg counts were performed on these samples, and L3 were collected from pooled coprocultures. Deep amplicon sequencing was used to determine both the species composition of these L3 and the proportions of benzimidazole-resistant single nucleotide polymorphisms in the isotype-1 β-tubulin locus of the predominant species, Teladorsagia circumcincta L3. Despite consistent management throughout the study, the results show variation in gastrointestinal nematode species composition with time and between age groups, that was potentially associated with weather conditions. The F200Y benzimidazole resistance mutation is close to genetic fixation in the T. circumcincta population on this farm. There was no evidence of variation in isotype-1 β-tubulin single nucleotide polymorphisms frequency between age groups, and no genetic evidence of reversion to benzimidazole susceptibility, despite targeted benzimidazole usage. This study highlights the need to include speciation when investigating gastrointestinal nematode epidemiology and anthelmintic resistance, and serves as an example of how genetic data may be analysed alongside species diversity and faecal egg counts, when markers for other anthelmintic classes are identified.

Gastrointestinal nematodes (GIN) negatively impact productivity and welfare in sheep globally and are estimated to cost the European sheep industry €157-477 million annually. GIN are mainly controlled by anthelmintic treatment, however, as anthelmintic resistance becomes prominent, the routine treatment of ewes against GIN has been questioned. A questionnaire survey of 383 sheep farmers in Great Britain was conducted to identify strategies currently used to control GIN infections in ewes. Ordinal and binary regression analysis were used to identify factors associated with use of practices known to influence anthelmintic resistance development, including number and timing of ewe GIN anthelmintic treatment, targeted selective treatment (TST) of ewes, drench and move of ewes and long-acting moxidectin treatment of periparturient ewes. Participating farmers treated their ewes against GIN 1.68 times per year on average, with 42.3% and 32.1% of participating farmers worming their ewes once or twice a year on average, respectively. 17.2% of participating farmers wormed their ewes more than twice a year, and 8.4% never worm their ewes. Participating farmers who devised GIN control strategies based on SCOPS guidelines treated their ewes significantly less per year (P 0.001), whilst those determining treatment timing based on ewe DAG scores or the time of year treated their ewes significantly more frequently (P 0.001). Farmers who devised GIN control strategies in conjunction with their vet had greater odds of using TST (P 0.001), as well as farmers who determined flock treatment timing based on ewe condition (P = 0.027). The use of narrow spectrum flukicides was significantly associated with reduced number of annual ewe GIN anthelmintic treatments (P 0.001), TST of ewes against GIN (P 0.001) and the avoidance of moving ewes to clean pastures following GIN treatment (P 0.001). The presence of sheep scab on a farm or in the area was significantly associated with increased annual GIN treatments for ewes (P = 0.002), not using TST strategies to control GIN in ewes (P 0.001) and moving ewes to clean pasture after anthelmintic treatment, whilst using macrocyclic lactones treatments to prevent sheep scab was significantly associated with the treatment of periparturient ewes with long-acting moxidectin (P = 0.001). This research suggests that by encouraging the application of evidence based targeted or targeted selective treatment strategies, further interaction between farmers and veterinarians/SCOPS guidance, and the uptake of best practices for controlling liver fluke and sheep scab on farms, sustainable GIN control strategies can become the common practice in ewes.

The development of resistance to commercial anthelmintics, particularly in different species of gastrointestinal nematodes (GINs), requires the search for alternatives. Within that context, the aim of this study was to evaluate the in vitro ovicidal activity of five different essential oils (EOs): Origanum vulgare, Satureja hortensis, Thymus vulgaris, Mentha x piperita and Helichrysum arenarium against sheep GINs. For this purpose, the nematode eggs were collected from naturally infected sheep by GINs in two farms located in southern Italy. The egg hatch test (EHT) was performed at six different concentrations (50, 12.5, 3.125, 0.781, 0.195 and 0.049 mg/mL) for each EO. Gas chromatography-mass spectrometry chemical analyses of tested EOs, as well as coproculture examination of tested faecal samples, were also conducted. The results of EHT showed the greatest ovicidal activity of O. vulgare EO with a maximum effect on egg hatching (100%) for all tested concentrations. A similar effect was also shown by S. hortensis and T. vulgaris EOs with an activity of 99.3-100% and 98.5-100%, respectively. M. piperita EO showed medium, dose-dependent ovicidal activity with an inhibitory effect of 72.5-99.8% on the egg hatchability, while the least effective was H. arenarium EO with an activity of 59.8-69.3%. For the anthelmintic activities of the tested EOs are responsible their ingredients, above all carvacrol, thymol, p-cymene and γ-terpinene. The present study demonstrated the significant anthelmintic potential of the tested EOs and emphasizes the possible importance of medicinal plant products for the control of gastrointestinal parasites in sheep.

The worldwide increased difficulty to counteract gastrointestinal nematode (GIN) infection in sheep, due to progressing anthelmintic resistance, has led to the evaluation of other alternative helminth control options, mainly from plants. The anthelmintic efficacy of an aqueous Punica granatum macerate was evaluated in sheep naturally infected by GIN in southern Italy. The macerate was chemically characterized by chromatographic analysis coupled with high-resolution mass spectrometry (LC/HRMS) and an aliquot was concentrated to obtain a dry extract. A part was characterized, the remaining washed with methanol to obtain an insoluble residue and methanol phase. In the methanol fraction, the quantitatively predominant gallic acid was purified to obtain the pure molecule. The three fractions thus obtained were used for in vitro studies (i.e., egg hatch test) to verify anthelmintic efficacy. For this purpose, fecal samples were collected from sheep naturally infected by GINs. Fractions were diluted in H2O/DMSO 0.5% at 1.00, 0.5, 0.25, 0.125, 0.05, and 0.005 mg/mL concentrations. Thiabendazole (0.25 and 0.5 mg/mL) and deionized water were used as positive and negative controls, respectively. Egg hatch test results indicated that all fractions caused a significant (p &lt, 0.05) egg hatch inhibition within 48 h of exposure highlighting a high (&gt, 82%) efficacy in vitro at all tested doses. Maximal egg hatching inhibition effect was exhibited by the methanol fraction (99.3% and 89.3% at 1 and 0.005 mg/mL concentrations), followed by the insoluble residue and gallic acid (94.7% and 85.3% and 94.0% and 82.7% at 1 and 0.005 mg/mL, respectively). The current study validated the anthelmintic potential of traditional P. granatum macerate against GIN infection in sheep, thus highlighting the role of gallic acid as principal component and justifying a need to undertake further in vivo studies on these ethno-veterinary remedies.

Our current understanding of differences in the epidemiology of gastrointestinalnematode (GIN) species in co-grazed sheep and goats is inadequate with reference to the development of sustainable control strategies. The next-generation metabarcoded sequencing method referred to as the ‘nemabiome’ allows some of these differences to be explored to describe the intensity of co-infecting GIN species. We applied this platform to study sheep and goats that were co-grazed on Guinea grass pasture in northeastern Brazil. Co-grazed goats and sheep were treated with a monepantel anthelmintic, then exposed to the same gastrointestinal nematode species. Overall, there were differences in the prevalence of GIN species identified in the sheep and goats;Trichostrongylus colubriformis and Teladorsagia circumcincta predominated in goat kids, while Haemonchus contortus predominated in adult does, ewes and lambs once burdens became re-established after anthelmintic treatment. Description of the pattern of re-infection following anthelmintic treatment was prevented by the unpredicted poor efficacy of 2.5 mg/kg and 5 mg/kg, respectively, of monepantel against O. columbianum and T. circumcincta in lambs, and T. circumcincta adult does. Differences in drug efficacy between host age and species groups may be important when considering sustainable GIN control strategies for co-grazed animals. The aggregated FECs of the adult does and goat kids representing re-established GIN burdens, were higher than those of the co-grazedadult ewes and lambs. This implies that there are inherent differences in GIN species adaptation to the two naïve small ruminant host species, and shows the need for better understanding of the factors giving rise to this situation associated with exposure to infective larvae and host responses. At the start of the study, the adult does were coinfected with several GIN species, with the highest intensity of T. circumcincta, contrasting with the situation in the adult ewes, in which H. contortus predominated.However, once burdens became re-established after treatment, H. contortus predominated in both adult does and ewes. This demonstrates the potential for host burdens of H. contortus to establish and predominate after anthelmintic treatment when burdens of coinfecting GIN species are low.

This study aimed to determine control measures for gastrointestinal nematodes in goats in the northeastern semiarid after analyzing the dynamics of gastrointestinal helminths during the drought, the evolution of the parasitic load after the first rains and the differences in susceptibility between goats of different categories and ages. Five farms were studied from March 2013 to January 2015. Feces were collected from all goats every month, for fecal egg counts (FECs). No treatment was required on any farm during the dry period. In 2013, with annual rainfall of 265-533 mm, treatments were not necessary during the rainy season. However, in 2014, with rainfall of 604-778 mm, treatments were necessary 60-90 days, after the first rains. On three farms, gastrointestinal nematodes showed multiple anthelmintic resistance. The FECs from lactating goats were significantly higher than from dry and young goats. In conclusion, in the Brazilian semi-arid region (Caatinga biome), it is generally unnecessary to treat grazing goats during the dry season. In the rainy season, the parasite load increases 2-3 months after the first rains. In both, the dry and the rainy season, farmers should monitor their herds by means of FEC or another criterion (anemia or submandibular edema), to determine the need to treat. RESUMO: Este trabalho objetivou determinar medidas de controle de nematódeos gastrintestinais de caprinos no semiárido nordestino após análise da dinâmica das infecções helmínticas durante a seca, a evolução da carga parasitária após as primeiras chuvas e as diferenças de susceptibilidade entre caprinos de distintas categorias e idades. Em cinco propriedades, de março de 2013 a janeiro de 2015, foram coletadas, mensalmente, fezes de todos os caprinos para contagem de ovos. Em nenhuma propriedade foi necessário vermifugar durante os períodos de seca. Em 2013, com precipitações de 265-533 mm anuais, não foi necessário vermifugar durante o período de chuva. No entanto, em 2014, com precipitações de 604-778 mm, foi necessário vermifugar 60-90 dias após as primeiras chuvas em três propriedades. Nessas três propriedades foi encontrada multirresistência aos anti-helmínticos. Foi constatado que o OPG das cabras lactantes foi significativamente maior do que o OPG das cabras secas e dos cabritos. Em conclusão, na região semiárida, geralmente, não é necessário o tratamento das cabras pastejando na caatinga durante a estação seca. Na estação chuvosa, a carga parasitária aumenta 2-3 meses após as primeiras chuvas. Tanto na seca quanto nas chuvas, o produtor deve monitorar o rebanho mediante OPG ou por outros critérios (anemia, edema submandibular) para determinar a necessidade de vermifugação.

Gastrointestinal nematode (GIN) parasitism, particularly Haemonchus contortus infection, is of grave concern to producers due to its ability to dramatically decrease the productivity and profitability of livestock. With increasing resistance to commonly used antihelmintics, it is important to investigate alternative GIN therapy methods. Copper oxide wire particles (COWP) administered as an oral bolus are effective at decreasing fecal egg counts and H. contortus concentrations in sheep and goats. The use of this alternative method of parasite control has not been evaluated in new world camelids. The purpose of this study was to determine if COWP administered as an oral bolus would effectively decrease fecal GIN egg counts in adult alpacas., American Association of Bovine Practitioners Proceedings of the Annual Conference, 2020

The aims of this study were to determine the prevalence of gastrointestinal nematodes (GIN) in horses, donkeys and mules and its associations with age, sex and climatic factors (derived from satellite data) to identify the potential risk factors of different climate regions in four Mexican states. From May 2017 to April 2018, a total of 560 farm owners or managers answered the questionnaire, and the data were used to establish three Koppen climate classes (tropical, dry, temperate). The overall prevalence of GIN parasites in equines was 77.9% (436 out of 560). The highest percentage of GIN was detected in mules (87.5%). In addition, the highest prevalence among the climate regions was found in the temperate climate (79.9%). The identified nematodes were strongyle type (77.9%), Parascaris equorum (5.7%), Strongyloides (0.7%) and Oxyuris equi (2.9%). The highest mean value of strongylid eggs per g faeces was found in the dry climate (632.6 ± 96.8), followed by that in the tropical climate (518.3 ± 49.7) and temperate climate (383.8 ± 30.2); however, a similar prevalence was observed between different climate regions. Age and sex were identified as risk factors for high shedding of strongyle eggs: the odds ratios for higher shedding intensities were 3.858 for geldings compared to mares, 2.602 for 6–10-year-old equines and 3.597 for ≤16-year-olds compared to young equines (≤5 years old).

As the global incidences of colorectal cancer rises, there is a growing importance in understanding the interaction between external factors, such as common infections, on the initiation and progression of this disease. While certain helminth infections have been shown to alter the severity and risk of developing colitis-associated colorectal cancer, whether these parasites can directly affect colorectal cancer progression is unknown. Here, we made use of murine and human colorectal cancer cell lines to demonstrate that exposure to antigens derived from the gastrointestinal nematode Heligmosomoides polygyrus significantly reduced colorectal cancer cell proliferation in vitro. Using a range of approaches, we demonstrate that antigen-dependent reductions in cancer cell proliferation and viability are associated with increased expression of the critical cell cycle regulators p53 and p21. Interestingly, H. polygyrus-derived antigens significantly increased murine colorectal cancer cell migration, which was associated with an increased expression of the adherens junction protein &beta, catenin, whereas the opposite was true for human colorectal cancer cells. Together, these findings demonstrate that antigens derived from a gastrointestinal nematode can significantly alter colorectal cancer cell behavior. Further in-depth analysis may reveal novel candidates for targeting and treating late-stage cancer.

Infections with gastrointestinal nematodes (GIN) adversely affect meat color in lambs. Although white-rot fungi (WRF) pretreatment increases nutritional value and fiber digestion of corn straw for lambs, whether it can improve meat quality of lambs infected with GINs is unknown. The objective of this experiment was to study effects of feeding WRF-pretreated corn straw on the health and meat quality of lambs infected with GINs. Sixteen healthy Ujumqin lambs were orally drenched with 3rd-stage GINs larvae and randomly divided into two dietary treatments of control (CON) and WRF diets for 70 days of feeding. Results showed that feeding WRF-pretreated corn straw decreased L* and b* values (p &lt, 0.05) and increased a* value (p &lt, 0.01) of both longissimus thoracis et lumborum (LTL) and semimembranosus (SM) muscles of lambs infected with GINs. Feeding WRF-pretreatment corn straw decreased fecal egg count (p = 0.014) and increased packed cell volume (p = 0.013) of lambs from 28 d of feeding and increased plasma iron content (p = 0.008) of lambs from 56 d of the feeding. Feeding WRF-pretreatment corn straw decreased myosin heavy-chain (MyHC)-I (p = 0.032) and MyHC-II&alpha, (p = 0.025) content in LTL muscle and MyHC-I (p = 0.022) and MyHC-II&beta, (p = 0.048) in SM muscle of lambs. In conclusion, although there were no significant changes in the content of most amino acids or increased intensity of better flavor compounds, meat quality and health of lambs infected with GINs was significantly improved by feeding WRF-pretreated corn straw due to increased PCV and meat color and tenderness.

The gastrointestinal nematode parasite Haemonchus contortus (H. contortus) is a resident of tropical and subtropical regions worldwide that imposes significant production losses, economic losses, and animal health issues in the small ruminant industry, particularly sheep and goats. Considerable efforts have been made to understand how immunity is elicited against H. contortus infection. Various potential vaccine antigens have been tested by different methods and strategies applied in animal models, and significant progress has been made in the development of vaccines against H. contortus. This review highlighted and shared the knowledge about the current understanding of host immune responses to H. contortus and ongoing challenges in the development of a protective, effective, and long-lasting vaccine against H. contortus infection. We have also pinpointed some achievements and failures in the development and testing of vaccines, which will establish a road map for future research directions to explore new effective vaccine candidates for controlling and preventing H. contortus infection.

Toxocariasis is a zoonotic disease affecting humans that is predominantly caused by Toxocara canis and T. cati, primarily parasites of dogs and cats, respectively. Toxocara generally establishes long-term infections by co-opting its host&rsquo, s physiological processes, while at the same time exploiting the nutritional environment. Adult stage T. canis reside in the gut of the definitive canine host where they employ a suite of strategies to combat intestinal immune responses by actively producing and releasing excretory-secretory products (ESPs). The protein component of T. canis ESPs has been widely studied, but characterisation of the non-protein ESP complement remains neglected. To characterize the secreted metabolome of Toxocara ESPs and to shed light on the parasite&rsquo, s metabolic processes, we profiled the ESPs of T. canis using both gas chromatography (GC) and liquid chromatography (LC) mass spectrometry approaches. We successfully identified 61 small molecules, including 41 polar metabolites, 14 medium-long chain fatty acids (MLCFAs) and six short chain fatty acids (SCFAs). We identified talose, stearic acid and isovalerate as the major compounds belonging to the polar, MLCFA and SCFA chemical classes, respectively. Most of the 61 identified metabolites appear to have been produced by T. canis via three distinct metabolic pathways - fatty acid, amino acid and carbohydrate metabolism. The majority of the identified ESPs have known biological properties, especially as immunomodulators. However, there is limited/no information on the biological roles or applications of 31 ESP biomolecules, suggesting that these may have novel activities that merit further investigation.

Toxocariasis is a zoonotic disease affecting humans that is predominantly caused by Toxocara canis and T. cati, primarily parasites of dogs and cats, respectively. Toxocara generally establishes long-term infections by co-opting its host’s physiological processes, while at the same time exploiting the nutritional environment. Adult stage T. canis reside in the gut of the definitive canine host where they employ a suite of strategies to combat intestinal immune responses by actively producing and releasing excretory-secretory products (ESPs). The protein component of T. canis ESPs has been widely studied, but characterisation of the non-protein ESP complement remains neglected. To characterize the secreted metabolome of Toxocara ESPs and to shed light on the parasite’s metabolic processes, we profiled the ESPs of T. canis using both gas chromatography (GC) and liquid chromatography (LC) mass spectrometry approaches. We successfully identified 61 small molecules, including 41 polar metabolites, 14 medium-long chain fatty acids (MLCFAs) and six short chain fatty acids (SCFAs). We identified talose, stearic acid and isovalerate as the major compounds belonging to the polar, MLCFA and SCFA chemical classes, respectively. Most of the 61 identified metabolites appear to have been produced by T. canis via three distinct metabolic pathways - fatty acid, amino acid and carbohydrate metabolism. The majority of the identified ESPs have known biological properties, especially as immunomodulators. However, there is limited/no information on the biological roles or applications of 31 ESP biomolecules, suggesting that these may have novel activities that merit further investigation.

214 p. La actual tesis doctoral, que se ha desarrollado en el grupo de investigación de mejora genética animal de la Universidad de León (grupo MEGA-ULE), tiene como objetivo global el estudio de la base genética subyacente a la resistencia a los nematodos gastrointestinales (GIN) en ovejas adultas. Para ello se han utilizado metodologías empleadas en la genómica, tales como el chip de genotipado de SNPs de alta densidad (HD) y las tecnologías se cuenciación conocidas como next generation sequencing (NGS). Para el cumplimiento el objetivo global se han abordado dos objetivos específicos. El primero de ellos tuvo por objeto realizar un mapeo de alta densidad de regiones con influencia sobre la resistencia a los GIN en ovejas mediante el análisis de genotipos imputados para el chip HD-chip en una población de raza Churra previamente analizada con el chip de media densidad (50K-chip) y para la cual estaban disponibles datos de dos fenotipos relacionados con la carga parasitaria. El segundo objetivo específico se centró en la caracterización funcional de regiones genómicas asociadas con la resistencia a los GIN en ovejas adultas, utilizando el análsis del transcriptioma completo de diferentes tejidos (ganglio linfático abomasal y mucosa del abomaso) después de la infección experimental con T. circumcincta, mediante la metodología RNAseq.

Graphical abstract, Highlights • Many small RNAs in extracellular vesicles (EVs) from diverse nematodes derive from intergenic and repetitive elements. • The parasite microRNA (miRNA) content of EVs is consistent across multiple EV isolation protocols and laboratories. • Trichuris muris and Heligmosomoides bakeri EVs contain distinct parasite miRNA family members. • Trichuris muris EVs purified across different laboratories consistently contain more mouse miRNAs than H. bakeri. • Comparisons of helminth EV cargos could help identify sRNAs involved in cross-species communication and niche specificity., Extracellular vesicles (EVs) have emerged as a ubiquitous component of helminth excretory-secretory products that can deliver parasite molecules to host cells to elicit immunomodulatory effects. RNAs are one type of cargo molecule that can underpin EV functions, hence there is extensive interest in characterising the RNAs that are present in EVs from different helminth species. Here we outline methods for identifying all of the small RNAs (sRNA) in helminth EVs and address how different methodologies may influence the sRNAs detected. We show that different EV purification methods introduce relatively little variation in the sRNAs that are detected, and that different RNA library preparation methods yielded larger differences. We compared the EV sRNAs in the gastrointestinal nematode Heligmosomoides bakeri with those in EVs from the distantly related gastrointestinal nematode Trichuris muris, and found that many of the sRNAs in both organisms derive from repetitive elements or intergenic regions. However, only in H. bakeri do these RNAs contain a 5′ triphosphate, and Guanine (G) starting nucleotide, consistent with their biogenesis by RNA-dependent RNA polymerases (RdRPs). Distinct microRNA (miRNA) families are carried in EVs from each parasite, with H. bakeri EVs specific for miR-71, miR-49, miR-63, miR-259 and miR-240 gene families, and T. muris EVs specific for miR-1, miR-1822 and miR-252, and enriched for miR-59, miR-72 and miR-44 families, with the miR-9, miR-10, miR-80 and let-7 families abundant in both. We found a larger proportion of miRNA reads derive from the mouse host in T. muris EVs, compared with H. bakeri EVs. Our report underscores potential biases in the sRNAs sequenced based on library preparation methods, suggests specific nematode lineages have evolved distinct sRNA synthesis/export pathways, and highlights specific differences in EV miRNAs from H. bakeri and T. muris that may underpin functional adaptation to their host niches.

Made available in DSpace on 2020-12-10T17:32:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-05-03 The aim of this study was to perform in vitro screening of the antiparasitic potential of thirty-five plant extracts against the gastrointestinal nematode (GIN) Haemonchus contortus and the cattle tick Rhipicephalus microplus. The larval development test (LDT) and egg hatch test (EHT) were performed to assess the activity against GIN; and the larval packet test (LPT), larval repellency test (RT) and adult immersion test (AIT) were used to assess the acaricidal effect. In the EHT, the Senecio brasiliensis aqueous extract had the best IC50 value (1.2 mg.mL(-1)). In the LPT and AIT, Schinus lentiscifolius hexane extract presented best acaricidal effect, with 100% efficacy at 50 mg.mL(-1) and IC50 of 2.1 mg.mL(-1), respectively. In summary, S. brasiliensis demonstrated potential for the control of GIN, while S. lentiscifolius showed outstanding efficacy against cattle tick, therefore both have potential for future studies related to isolation of bioactive substances and toxicological and pre-clinical experiments. Embrapa Pecuaria Sudeste, Rodovia Washington Luiz, Sao Carlos, SP, Brazil Univ Estadual Paulista, Fac Ciencias Agr & Vet, Jaboticabal, SP, Brazil Univ Fed Santa Maria, Fac Ciencias Agr & Vet, Santa Maria, RS, Brazil Embrapa Pecuaria, Fac Ciencias Agr & Vet, Bage, RS, Brazil Univ Estadual Paulista, Fac Ciencias Agr & Vet, Jaboticabal, SP, Brazil

The objective of the present study was to study, under field conditions, potential associations between gastrointestinal nematode parasitism and subclinical mastitis in ewes during the lactation period. Faecal and milk samples were collected from 240 ewes in 16 farms, for parasitological and bacteriological plus cytological examination, respectively. In the population sampled, prevalence of gastrointestinal nematode infection was 63.0%; mean faecal count was 357.7 ± 32.4 eggs per gram (epg); Teladorsagia spp. larvae were identified more frequently in coprocultures (median proportion among farms: 53.0%). The prevalence of subclinical mastitis was 22.6%; coagulase-negative Staphylococcus spp. were identified more frequently as causal agents (64.7% of isolates recovered from cases of the disease). There was clear evidence that the prevalence of subclinical mastitis was higher among ewes with gastrointestinal nematode infection than among ewes without: 26.4% and 16.1% (P = 0.047), respectively. Further, the prevalence of subclinical mastitis was higher in ewes with high faecal epg: 31.1% versus 18.6% in ewes with low faecal epg (P = 0.027). Mean epg counts in ewes with mastitis were significantly higher: 500 ± 84 (mean ± standard error of the mean), than epg counts in healthy ewes: 316 ± 36 (P = 0.024). The findings further underline the importance of concurrent parasitic and bacterial infections. Moreover, results also suggest further factors that can play a role in development of mastitis in ewes.