Gastrointestinal Nematodes Of Small Ruminants Research Articles

Haemonchosis in Small Ruminants Under Traditional Husbandry Systems in Apac District, Northern Uganda.

Haemonchus contortus is one of the most common and fatal pathogenic gastrointestinal nematodes of small ruminants causing significant economic losses, particularly in low-income countries. A cross-sectional study was carried out in randomly selected small ruminants kept under traditional husbandry systems in the Apac district (now split into Apac and Kwania districts) in northern Uganda to assess the prevalence, intensity, and associated risk factors of H. contortus infection from May 2018 to January 2019. Faecal samples were collected from a total of 768 randomly selected small ruminants (384 sheep and 384 goats) and examined for parasites using the floatation method and coproculture. The overall prevalence of H. contortus in small ruminants was 73.3% (563/768) by faecal egg count and 70.6% (542/768) by coproculture. The mean number of eggs per gram of faeces in small ruminants was 2046 ± 107 and differed significantly across the host animals ranging from 1729 ± 120 (mean ± SE) in goats to 2364 ± 176 in sheep. Significant predictors of infection were the origin of study animals, animal species, breed of animal, age of study animal, faecal consistency, lactation, multispecies grazing, grazing method, and anthelmintic use. The findings of our study provide information on the current status of H. contortus infections in goats and sheep under traditional husbandry systems in Uganda which are critical in designing effective control strategies for the disease.

Anti-parasitic activities of four synthetic chemicals anthelmintics on Haemonchus contortus

Synthetic anthelmintic (AHs) have always been used in veterinary medicine. The increasing development of resistance to these AHs in livestock parasites threatens animal health and global production, calling into question their effectiveness. In vitro egg hatch inhibition assay (EHA) and larval development test (LDT) performed showed ovicidal and larvicidal activities of four AHs compared to the control (PBS). However, a suspicion of Haemonchus contortus resistance to Bolumisole M1 (IC50 = 0.122µg/mL) and Ivomec-D (IC50 = 0.130µg/mL) was recorded after the EHA. Similarly, resistance was observed to Bolumisole M1 (IC50 = 0.024µg/mL), Ivomec-D (IC50 = 0.07µg/mL) and Kelanthic (IC50 = 0.144µg / mL) following the LDT. These results show that cases of parasite resistance to AHs exist in small ruminants in Burkina Faso. Therefore, a reasoned use of AHs could be a good approach in the control of gastrointestinal nematodes of small ruminants in Burkina Faso. Subsequent in vivo studies should be conducted to confirm this resistance in the real conditions of these ruminants.

Five past twelve - the resistance situation in small ruminant gastrointestinal nematodes in Germany

Anthelmintic resistance has reached alarming levels worldwide and already seriously threatens pasture-based small ruminant production in certain geographic regions. The situation in Europe has also dramatically deteriorated in the last decade. This review provides an overview of the occurrence of anthelmintic resistance in small ruminants with a particular focus on Germany and its neighbouring countries. It also covers mechanisms leading to the development and spread of anthelmintic resistance, and recommendations for a responsible use of anthelmintics in veterinary practice.

Agro-industrial residues in the control of gastrointestinal nematodes of small ruminants and fertilization of forages

ABSTRACT: Verminosis in small ruminants can render rural activity impractical, which is still controlled through the administration of anthelmintics. The present study evaluated four agro-industrial residues as fertilizer in the control of GIN of small ruminants in the free-living stage. Crab shell, manipueira, biochar, and organomineral residues were used in pots (5.0 kg of soil) and cultivated with Massai grass (Megathyrsus maximum cv. Massai). Further, the pots were contaminated with feces from sheep carrying a natural multispecific infection by GIN. Next, the residues were applied individually to the soil, with 50 mL/pot for liquid and 50 g/pot for solid residues. Treatment with manipueira showed the lowest number of L3.kg MS-1 recovered from the grass (202.44), when compared with treatments using organomineral (823.89) and biochar (689.34). However, there was no statistically significant difference (P < 0.05) between the four treatments as compared to the control group. These agro-industrial residues can be used as organic fertilizers; however, these will not help in the control of GIN in sheep.

Signs of multiple anthelmintic resistance in sheep gastrointestinal nematodes in Sweden.

Gastrointestinal nematodes in small ruminants are clinically and economically important parasites that often are controlled with anthelmintics. In this study, we compiled information on the anthelmintic efficacy collected on sheep farms according to routines established by Farm & Animal Health in Sweden. The efficacies of benzimidazoles (i.e. albendazole or fenbendazole, n=30), ivermectin (n=47), levamisole (n=2) or moxidectin (n=2) were examined between 2015 and 2021 in 81 treatment groups on 49 non-randomly selected farms in south-central Sweden. Drug efficacies were estimated with the faecal egg count reduction test. In addition, efficacy data were in most cases supplemented with data on the abundance of the three most common nematode genera in sheep by performing droplet digital (dd) PCR on coprocultures. Efficacies of <95% for benzimidazoles or ivermectin were identified in 37% and 77% of the tested groups, respectively. In addition, on 27 (55%) of the 49 farms where both benzimidazoles and ivermectin were tested, multiple resistance was found on 8 (30%). In contrast, on each of the two farms tested for levamisole and moxidectin both drugs proved to be 100% effective. However, because post-sampling was performed earlier than recommended in several susceptible groups (benzimidazoles=15, and ivermectin=10 groups), this could have underestimated the severity of the situation. Mainly larvae from the genus Haemonchus were detected in post-treatment coprocultures, in all groups with declared resistance, suggesting that this parasite was primarily associated with anthelmintic resistance. Unexpectedly, the DNA of larvae, which survived treatment, was also detected on farms declared as susceptible. Taken together, this indicates that the situation regarding the anthelmintic efficacy has deteriorated compared with the latest nationwide study on Swedish sheep farms conducted more than a decade ago. Unlike the previous study, the farm selection here was not strictly randomized but rather opportunistic i.e., only farms with a recognized parasite problem were included. Thus, there is a need for a truly randomized study to get an update on the extent of the situation of anthelmintic resistance at a national level, as well as to identify risk factors involved in the resistance selection. Research is also required to establish the optimal intervals for sampling post-treatment.

Phenolic Acids and Flavonoids from Pithecellobium dulce (Robx.) Benth Leaves Exhibit Ovicidal Activity against Haemonchus contortus.

Pithecellobium dulce (Robx.) Benth is an arboreal legume used in traditional medicine for the treatment of several ailments, including a number of intestinal disorders, and as a natural deworming. The objective of this study was to evaluate the ovicidal activity of a hydroalcoholic extract (HA-E) and its fractions (aqueous, Aq-F and organic, EtOAc-F) from P. dulce leaves, as well as subfractions (C1F1–C17) obtained from EtOAc-F against Haemonchus contortus eggs. The HA-E, Aq-F, and EtOAc-F were assessed at 0.03–5.00 mg/mL and subfractions (C1F1–C17) were assessed at 0.06–1.00 mg/mL. The HA-E and Aq-F showed an ovicidal activity close to 100% at 2.5 mg/mL, and EtOAc-F displayed the highest anthelmintic effect (100% at 0.25 mg/mL). Meanwhile, the sub-fractions with the highest ovicidal effect were C1F6, C1F9, C1F10, C1F11, and CIF13. The main compounds identified in the most active fractions (C1F9, C1F11, and C1F13) were kaempferol (1), quercetin (2), coumaric acid (3), ferulic acid (4), luteolin 7-O-rhamnoside (5), quercetin 3-O-rhamnoside (6), and a caffeoyl derivate (NI). The results indicate that P. dulce leaves exhibit a potent anthelmintic activity and contain bioactive compounds able to inhibit egg hatching in H. contortus. Therefore, this plant could be used for the control of gastrointestinal nematodes in small ruminants.

In vitro anthelmintic activity of an R-carvone nanoemulsions towards multiresistant Haemonchus contortus.

This work aimed to evaluate the in vitro anthelmintic effect of carvone nanoemulsions on Haemonchus contortus. Three R-carvone nanoemulsions were prepared: uncoated R-carvone nanoemulsions homogenized in a sonicator (UNAlg-son) and homogenized in an ultrahomogenizer (UNAlg-ultra) and sodium alginate-coated R-carvone (CNAlg-ultra). The physicochemical characterizations of the nanoemulsions were carried out. The anthelmintic activity was evaluated using egg hatch test (EHT), larval development test (LDT) and adult worm motility test (AWMT). Changes in cuticle induced in adult H. contortus were evaluated by scanning electron microscopy (SEM). The results were subjected to analysis of variance and compared using the Tukey test (P < 0.05). The effective concentration to inhibit 50% (EC50) of egg hatching and larval development was calculated. The particle sizes were 281.1 nm (UNAlg-son), 152.7 nm (UNAlg-ultra) and 557.8 nm (CNAlg-ultra), and the zeta potentials were −15 mV (UNAlg-son), −10.8 mV (UNAlg-ultra) and −24.2 mV (CNAlg-ultra). The encapsulation efficiency was 99.84 ± 0.01%. SEM of the nanoemulsions showed an increase in size. In EHT, the EC50 values of UNAlg-son, UNAlg-ultra and CNAlg-ultra were 0.19, 0.02 and 0.17 mg mL−1, respectively. In LDT, they were 0.29, 0.31 and 0.95 mg mL−1 for UNAlg-son, UNAlg-ultra and CNAlg-ultra, respectively. The adult motility inhibition was 100% after 12 h of exposure to UNAlg-ultra and CNAlg-ultra, while for UNAlg-son, it was 79.16%. SEM showed changes in the buccal capsule and cuticular damage. It was concluded that R-carvone nanoemulsions showed antiparasitic action demonstrating promise for the control of infections caused by gastrointestinal nematodes in small ruminants.

Assessment of three DNA extraction kits for the absolute quantification of strongyle nematode eggs in faecal samples

BackgroundHaemonchus contortus is one of the most pathogenic gastrointestinal nematodes of small ruminants. The current diagnostic approach for the detection of this species relies on coproscopic methods, which both have low sensitivity and are time consuming. Methods employing detection through DNA amplification, such as droplet digital polymerase chain reaction (ddPCR), offer an advantageous approach to the diagnosis of H. contortus. However, DNA extraction protocols need to be constantly updated for the optimal retrieval of diagnostically usable template. Here, we describe the evaluation of three genomic DNA extraction kits for the detection and quantification of H. contortus ITS2 amplicon DNA from faecal samples, using droplet digital PCR.ResultsDNA samples, extracted from faecal material with the Nucleospin DNA Stool kit, produced the highest amounts of ITS2 amplicon copies and had the lowest coefficient of variation across different dilutions and sample types (fresh or frozen) out of the tested kits (Nucleospin DNA Stool, E.Z.N.A.® Stool DNA Kit and QIAamp Fast DNA Stool Mini Kit). Furthermore, the protocol of this kit has the fewest number of steps and the price of DNA extraction per sample is reasonable (2.77 €).ConclusionsThe Nucleospin DNA Stool kit is an attractive option for the detection and quantification of H. contortus DNA in faecal samples of small ruminants in a diagnostic setting.

Epidemiology of Gastrointestinal Nematodes in Small Ruminants in Gamo Zone, Southern Ethiopia, with a Special Reference to Field Survey on Parasite Management and Risk Factor Analysis

Gastrointestinal nematodes are a major constraint for small ruminant production. A cross-sectional study was conducted in the districts of Gamo Zone, Southern Ethiopia on 415 small ruminants (248 sheep and 167 goats) selected using simple random sampling technique from this region to investigate the epidemiology of gastrointestinal nematodes (GINs) and potential risk factors. Coprological examination using floatation, McMaster egg counting and larviculture were employed. The overall prevalence of gastrointestinal nematode was 68.92%. Different nematode types including strongyles (54.94%), Strongyloides papillosus. (2.65%) and Trichuris sp. (1.93%) were identified based on egg morphology with overall mean faecal egg count of 307.66 ± 38.02. Haemonchus, Trichostrongylus, Oesophagostomum, Bunostomum, Cooperia, Teladorsagia and Chabertia were identified from pooled culture. The study revealed female animals were 1.99 times (OR=1.99, 95%CI=1.16-3.41) more likely to be affected by GIN infection than males. Animals with poor (OR=2.92, 95%CI=1.32-6.45) and medium (OR=1.94, 95%CI=1.13-3.34) body condition were 2.92 and 1.94 times more likely to be affected by GINs than those with good body condition. Pregnant animals were 6.57 times (OR=6.57, 95%CI=1.49-28.89) more likely to have GINs than non-pregnant animals. Infection in young animals was 1.8 times higher (OR=1.8, 95%CI=1.05-4.2) than adults. Appropriate prevention and control methods have to be undertaken to overcome the existing problem and further study is needed to assess seasonal dynamics of the GINs.

In Vitro Nematocidal Properties from Two Extracts: Lippia graveolens Leaves and Delonix regia Flowers Against Eggs and Infective Larvae of Haemonchus contortus.

The objective of this study was to assay the ovicidal and larvicidal effects of two hydroalcoholic extracts (HA-E) and their aqueous fractions (Aq-F) and organic fractions (EtOAc-F) from Lippia graveolens (leaves) and Delonix regia (flowers) against the parasitic nematode Haemonchus contortus. The egg hatching inhibition test (% EHI) and mortality of infective larvae (% mortality) were used as biological models. The treatments of each plant (mg/mL, % EHI, and % mortality) were assigned as follows: HA-E (12.5-50, EHI; 25-200, mortality), Aq-F (6.25-25.00, EHI; 12.5-50, mortality), EtOAc-F (0.37-25, EHI; 3.12-50, mortality), negative controls (distilled water and methanol at 2% and 4%), and positive control (ivermectin at 5 mg/mL). Data were analyzed using a completely randomized design through an analysis of variance, considering the EHI and mortality percentages as the response variables. To identify the secondary metabolites, both plants were subjected to qualitative chemical analysis and HPLC. The results showed that both plants exhibited highly ovicidal and larvicidal effects. The bipartition in each HA extract allowed the increase of the anthelmintic effect in EtOAc-F, achieving a total ovicidal activity at 1.56 mg/mL and a larvicidal effect higher than 90% at 25 mg/mL. The qualitative chemical profile of both vegetal species identified alkaloids, flavonoids, condensed tannins, terpenes, and saponins. These results suggest that either L. graveolens leaves or D. regia flowers could be potential candidates for the control of parasitic gastrointestinal nematodes in small ruminants. However, in vivo studies with experimental animals to evaluate their possible toxicity and anthelmintic effect are necessary.

Anti-helminthic Activity of Plant Extracts against Gastrointestinal Nematodes in Small Ruminants - A Review

Anti-helminthic Activity of Plant Extracts against Gastrointestinal Nematodes in Small Ruminants - A Review

Control of gastrointestinal helminths in goats in a mixed grazing system with cattle

Due to the widespread resistance of small ruminant gastrointestinal nematodes (GIN) against anthelmintic drugs the established control strategies need to get adapted, aiming to reduce their high dependence from chemical drugs. Host-specific development of GIN can be used as a tool when grazing different species on the same pastures. The aim of this study was to estimate the effect of mixed grazing with cattle on the development of GIN infections in goats. Goat flocks with 3 heifers (Group Mix; Visp: n = 12, Chur: n = 15) and without heifers (Group Solo; Visp: n = 7, Chur: n = 15) were grazed separately on pastures at altitudes of 910 m (location Chur) and 1240 m (location Visp) above sea level resp. during one grazing season each. The composition of the mixed groups aimed to achieve a similar intake of roughage of both species. The stocking rate and the availability of roughage in the solo groups was balanced proportionately according to the situation in the mixed groups. The individual GIN egg excretion, the composition of the GIN larvae in the faeces, the FAMACHA©-Score and the pasture contamination with infective GIN larvae was determined in monthly intervals. At both sites the goats in the mixed groups showed a significantly lower mean GIN egg excretion compared with those of the Solo groups (p .

Improved Traditional Drugs: State of knowledge for the sustainable management of gastrointestinal parasitic nematodes of small ruminants

This article aims to present the current state of the fight against gastrointestinal parasites in small ruminants from Improved Traditional Drugs (DTI). A host of scientific documents were consulted by means of search engines to gather the information useful for this synthesis. The failure of conventional treatments has led to the use of new methods to treat digestive pathologies due to internal parasitism in herds of sheep and goats. These include, among others, herbal medicine, homeopathy, aromatherapy, the mixed grazing system for small and large ruminants, ... All plant parts of plants can be used in the preparation of remedies. Several scientific studies show that plants are full of chemical compounds that cause anthelmintic effects on gastrointestinal parasites in small ruminants. Literature searches have revealed that studies on DTIs in the management of gastrointestinal nematodes in small ruminants are non-existent. In addition to the forms (decocted, macerated, infused, etc.) traditionally used by breeders, there are other forms that can be used to make DTIs from plant extracts. There are capsules, capsules, tablets etc. The placing on the market of DTIs requires official authorization based on the safety and reproducibility of the products. From the documents consulted, it appears that scientific research has not yet focused on the formulation of DTIs for the treatment of gastrointestinal parasitic nematodes in small ruminants. It will be useful to manufacture them to facilitate access to veterinary care and the sustainable management of animal health.&#x0D; Keywords: Improved Traditional Drugs; Gastrointestinal nematodes; Small ruminants, West Africa; Central Africa.

Blood parameters and immune responses during haemonchosis

Article Details: Received: 2020-10-06 | Accepted: 2020-11-27 | Available online: 2021-01-31 https://doi.org/10.15414/afz.2021.24.mi-prap.29-32 The aim of this experiment was to determine the effect of medicinal plants ( Artemisia absinthium and Malva sylvestris ) as feed supplements on blood parameters, and local immune responses in the abomasum of Haemonchus contortus infected lambs. Twenty-four lambs were infected orally with 5000 L3 larvae of H. contortus and subsequently randomly divided into four groups: unsupplemented animals (UNS), animals with A. absinthium (ART), animals with M. sylvestris (MAL), and animals with a mix of two plants (ARTMAL). During the experiment, samples of blood were taken for evaluation of hemoglobin and albumin levels. All animals were humanely killed after 75 days of the experiment, and abomasum tissue samples were taken for histopathology. The hemoglobin concentration in the blood was influenced by time ( p&lt; 0.001) and in all groups decreased until day 45. The serum albumin levels were influenced by treatment ( p&lt; 0.05) and time ( p&lt; 0.001) and in all groups occurred reduction until the end of the experiment compared to day 15. The number of plasma cells was higher in ARTMAL compared to MAL ( p &lt; 0.05). UNS and ART had significantly higher numbers of mast cells compared to MAL ( p&lt; 0.01 and 0.05, respectively). The regeneration of abomasal tissue was most frequent in ARTMAL. The results showed that dietary supplementation by A. absinthium and M. sylvestris did not positively affected blood parameters but influenced local immune response in the abomasum of H. contortus infected sheep. Keywords: Haemonchus contortus , sheep, hemoglobin, abomasum, local immune response References Besier, R. et al. (2016). The Pathophysiology, Ecology and Epidemiology of Haemonchus contortus. In Gasser, RB and Samson-Himmelstjerna, G. Haemonchus contortus- Past, present and future trends. (1. ed.). London: Elsevier Ltd (pp. 95-143). Hoste, H. et al. (2016). Interactions between nutrition and infections with Haemonchus contortus and related gastrointestinal nematodes in small ruminants. Advances in Parasitology, 93, 239–351. https://doi.org/10.1016/bs.apar.2016.02.025 McRae, KM. et al. (2015). The host immune response to gastrointestinal nematode infection in sheep. Parasite Immunology, 37(12), 605-613. https://doi.org/10.1111/pim.12290. Mravčáková, D. et al. (2019). Natural chemotherapeutic alternatives for controlling of haemonchosis in sheep. BMC Veterinary Research, 15, 1-13. https://doi.org/10.1186/s12917-019-2050-2 Rouatbi, M. et al. (2016). Effect of the infection with the nematode Haemonchus contortus (Strongylida: Trichostrongylidae) on the haematological, biochemical, clinical and reproductive traits in rams. The Onderstepoort Journal of Veterinary Research, 83(1), 1-8. http://dx.doi.org/10.4102/ojvr.v83i1.1129 Váradyová, Z. et al. (2018). Effects of herbal nutraceuticals and/or zinc against Haemonchus contortus in lambs experimentally infected. BMC Veterinary Research, 14(1), 78. https://doi.org/10.1186/s12917-018-1405-4 Villalba, JJ. Et al. (2017). Phytochemicals in animal health: Diet selection and trade-offs between costs and benefits. Proceedings of the Nutrition Society, 76(2), 113-121. https://doi.org/10.1017/S0029665116000719

In vitro anthelmintic activity of an aqueous extract of Glycyrrhiza glabra and of glycyrrhetinic acid against gastrointestinal nematodes of small ruminants.

This study evaluated the in vitro anthelmintic activity of a liquorice (Glycyrrhiza glabra) root aqueous extract and of glycyrrhetinic acid at 30, 10, 5, 1, and 0.5mg/mL against sheep gastrointestinal nematodes (GINs), using the egg hatch test (EHT), the larval development test (LDT), and the larval migration inhibition test (LMIT). The compounds were applied on a mixture of GIN eggs and larvae, mainly Trichostrongylus spp. and Teladorsagia/Ostertagia spp. Cytotoxicity assays were also performed. In the EHT, both candidates showed significant concentration-dependent efficacy and were significantly more effective (p<0.001) at the highest concentrations (30 and 10mg/mL) than the lowest ones. In the LDT, only G. glabra showed a concentration-dependent effect (R2=0.924), but glycyrrhetinic acid (R2=0.910) had significantly higher efficacy than G. glabra root extract. Moreover, the efficacy of glycyrrhetinic acid at 30, 10, and 5mg/mL was significantly higher (p<0.001) than at lower concentrations. In the LMIT, G. glabra showed concentration-dependent efficacy (R2=0.971), while considerably reduced efficacy was observed for glycyrrhetinic acid (R2=0.855) at the lowest concentrations. These data suggest that the two compounds may have different mechanisms of action. In the LMIT, the 50% lethal concentration (LC50) of glycyrrhetinic acid (~5.12mg/mL) was > 2.0-fold lower when compared to G. glabra (12.25mg/mL). Analysis and previous findings indicated low toxicity for both compounds. The results obtained encourage in vivo studies aimed at evaluating the potential use of the tested compounds as natural de-wormers in ruminants.

Prevalence, species composition, and associated risk factors of small ruminant gastrointestinal nematodes in South Omo zone, South-western Ethiopia.

Objective:This study was conducted to generate data on the prevalence, species composition, and factors associated with small ruminant nematode infection in the South Omo zone, in South-western Ethiopia.Material and Methods:A cross-sectional study through fecal nematode parasite examination was conducted. Simple floatation test and coproculture, followed by Baermann technique, were used for nematode egg and third-stage larvae (L3) separation and identification. The McMaster method was used to calculate the egg per gram of feces (EPG).Results:From a total of 242 sheep and goats examined, 72.34% were infested with single or mixed nematode parasites. District, “Kebele”, species, body condition score, and age were significantly (p < 0.05) associated with nematode infestation. Simple logistic regression analysis indicated that nematode infestation in Bena-Tsemay district (78.33%) was significantly (p < 0.05) higher by a factor of 0.54 (OR 95% CI: 0.30–0.96) than Hamer district (66.39%). Among the species, caprine (79.43%) was significantly (p < 0.05) infested than ovine (62.37%) by a factor of 0.45 (OR 95% CI: 0.25–0.81). Moreover, infestation on poor (79.12%) and medium (70.96%) body conditioned animals was higher by a factor of 2.94 (OR 95% CI: 1.41–6.26) and 1.76 (OR 95% CI: 0.88–3.53) than on good body conditioned animals (63.79%). Likewise, infestation in age groups of 1–3 years (78.66%) and >3 years (84.40%) was significantly (p < 0.05) higher by a factor of 4.83 (OR 95% CI: 2.31–10.46) and 8.23 (OR 95% CI: 3.98–17.75) than younger age groups (41.37%), respectively. A moderate parasitic burden was observed on 52.90% of gastrointestinal nematodes (GIN)-infested animals with significantly (p < 0.05) higher EPG in females than males. Furthermore, mixed infestation of Trichostrongylus axei and Eimeria (6.19%), Haemonchus contortus and Eimeria (5.78%), and Trichostrongylus vitrines and Eimeria (5.78%) were dominantly identified. On the contrary, T. axei (15.70%), Eimeria (8.67%), H. contortus (7.43%), and Trichostrongylus colubriformis (7.02%) were dominant single infestations.Conclusion:The current study revealed the highest prevalence of GIN in the study area, which needs strategic control, needs to enhance community awareness toward GIN control and prevention, and to implement further investigation into anthelminthic efficacy to solve the problem.

In vitro ovicidal activity of two chemotypes of the yarrow (Achillea millefolium L.) essential oil against sheep gastrointestinal nematodes

Abstract The economic losses caused by gastrointestinal nematodes of small ruminants are increasing today due to the development of anthelmintic resistance. Therefore, researchers from different parts of the world are searching for new, alternative strategies to control these parasites. As a valuable natural resource, medicinal plants and their products have emerged as a viable option. The aim of this study was to evaluate in vitro ovicidal activity of two chemotypes of the yarrow (Achillea millefolium L.) essential oil against sheep gastrointestinal nematodes. For this purpose, nematode eggs were collected from naturally infected sheep of two farms located in Southern Italy to perform the egg hatch test. In both farms, the coproculture examination identified the presence of four genera of sheep GINs: Haemonchus, Trichostrongylus, Teladorsagia and Chabertia. Main components of the yarrow essential oil identified by GC-MS analysis were 1,8-cineole (41.69%), camphor (8.37%) and trans-chrysanthenyl acetate (4.90) for the type 1 and β-pinene (28.53%), β-caryophyllene (18.71%) and 1,8-cineole (11.69%) for the type 2. In vitro ovicidal activity was evaluated at six different concentrations (50, 12.5, 3.125, 0.781, 0.195 and 0.049 mg/mL), whereby the inhibitory effect of the essential oil (Achillea millefolium L.) on egg hatchability varied from 46.5-99.5% (type 1) and 69.6-97.25% (type 2) and all concentrations tested showed a significantly higher efficacy compared to the negative control (p&lt;0.0001). Furthermore, the inhibitory effect on egg hatching was similar (p&gt;0.05) to the positive control (98.0%) at concentrations of 50 mg/mL (99.5%), 12.5 mg/mL (98.0%) and 3.125 (95.25%) of the type 1, and at concentrations of 50 mg/mL (97.25%) and 12.5 mg/mL (90.0%) of the type 2. The obtained results suggested that the A. millefolium essential oil has high anthelmintic potential, especially azulene-free chemotype rich in 1,8-cineole and camphor, which requires confirmation in further in vivo studies.

Contrasting patterns of isotype-1 β-tubulin allelic diversity in Haemonchus contortus and Haemonchus placei in the southern USA are consistent with a model of localised emergence of benzimidazole resistance

The benzimidazoles are one of the most important broad-spectrum anthelmintic drug classes for parasitic nematode control in domestic animals and humans. They have been widely used in livestock, particularly in small ruminants for over 40 years. This has resulted in widespread resistance in small ruminant gastrointestinal nematode parasite species, especially Haemonchus contortus. Benzimidazole resistance mutations have also been reported in Haemonchus placei, but only at low frequencies, suggesting resistance is at a much earlier stage of emergence than is the case for H. contortus. Here, we investigate the haplotype diversity of isotype-1 β-tubulin benzimidazole resistance mutations and the population genetic structure of H. contortus and H. placei populations from sheep and cattle from the southern USA. Microsatellite genotyping revealed a low level of genetic differentiation in six H.placei and seven H. contortus populations examined. This is consistent with several previous studies from other regions, mainly in H. contortus, supporting a model of high gene flow between parasite populations. There was a single F200Y(TAC) haplotype present in all six H. placei populations across Georgia, Florida and Arkansas. In contrast, there were at least two different F200Y(TAC) haplotypes (up to four) and two different F167Y(TAC) haplotypes across the seven H. contortus populations studied. These results provide further evidence to support a model for benzimidazole resistance in Haemonchus spp, in which resistance mutations arise from a single, or the small number of locations, in a region during the early phases of emergence, and subsequently spread due to animal movement.

A systematic review and meta-analysis on the prevalence, distribution and nematode species diversity in small ruminants: a Nigerian perspective.

Despite the global projections that agriculture will have to feed an additional 3 billion of the world's population in the nearest future, the global trends and negative impacts of nematodes on livestock productivity are still on the increase. Here, we reported the burden of gastrointestinal nematodes in small ruminants in Nigeria. Six thousand, five hundred and eighty one of the 13,259 small ruminants reported in 40 eligible studies across 18 Nigerian States were infected with at least one nematode species, yielding an overall pooled prevalence (PP) of 58.3% (95% CI 48.8, 67.2). Regional PP varied significantly (P < 0.001) and ranged between 19.5 (95% CI 5.8, 48.7) and 83.7% (95% CI 68.5, 92.3). Seasonal PP was higher in the dry (Prev: 56.5%, 95% CI 34.2, 76.4) than the rainy (Prev: 43.2%, 95% CI 26.7, 61.3) season. Haemonchus species were the most prevalent 21.3% while, Trichuris ovis and Strongyloides species had the widest geographic distribution. Several species of nematodes of small ruminants are highly prevalent in Nigeria. An all-inclusive approach involving public education and standardised management practices that involve adequate hygiene and sanitation, strategic and prophylactic use of anthelmintics, rotational grazing and the control of arthropod intermediate hosts will reduce the economic losses due to these parasites and curtail possible transmission to humans.

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.