Haemonchus Contortus In Goats Research Articles

In vitro anthelmintic activity of aqueous extracts of seven medicinal plants against Haemonchus contortus in goats

In vitro anthelmintic activity of aqueous extracts of seven medicinal plants against Haemonchus contortus in goats

Prevalence of gastrointestinal parasites and molecular identification of beta-tubulin mutations associated with benzimidazole resistance in Haemonchus contortus in goats from selected districts of Uganda.

Gastrointestinal parasites are among the most economically important pathogens of small ruminants causing serious economic losses and animal welfare problems for the livestock industry worldwide. The emergence of anthelmintic resistant H. contortus in small ruminants is a serious problem because it undermines effective helminth control and results in reduced productivity. Little is known about resistance to benzimidazoles (BZ) in Haemonchus in goats and sheep in Uganda. The objective of this study was to determine the prevalence of gastrointestinal parasites and to identify the presence of benzimidazole resistance associated mutations in the β-tubulin isotype 1 gene of Haemonchus contortus in goats from selected districts of Uganda. A total of 200 goats from 10 districts of Uganda slaughtered at Kalerwe abattoir in Kampala were sampled for H. contortus adult worms. Faecal samples were also collected to detect other intestinal parasites. Faecal microscopy and analysis were performed using flotation and sedimentation techniques. DNA was extracted from adult worms and PCR and sequencing of the ITS- 2 region and β-tubulin isotype 1 gene performed to identify H. contortus species and to determine the presence of mutations associated with anthelmintic resistance respectively. Faecal microscopy showed that the most prevalent intestinal parasites were coccidia (98%), strongyles (97.5%), Strongyloides (82%), Paramphistomum (74.5%), Moniezia (46%), Fasciola (1.5%) and Trichuris (1%). Most goats had a high intestinal burden of coccidia (≥ 5000 oocyst per gram) and strongyles (≥ 1000 egg per gram), 65% and 67.5%, respectively. The prevalence of H. contortus adult worms was 63% (126/200). Sequencing of the partial β-tubulin isotype 1 gene of 54 Haemonchus contortus adult male isolates revealed the presence of mutations associated with anthelmintic resistance. The F200Y mutation was the most common mutation (13% of samples with good beta-tubulin sequences) followed by the E198A and E198K mutations, both found in 9% of sequenced samples. Mutation F167Y was not identified in any of the samples and there were no heterozygous individuals for any of the SNPS associated with BZ resistance that were identified in this study. These findings highlight the need for controlled use of anthelmintics especially benzimidazoles, to enable sustainable control of H. contortus in Uganda, and a need for further investigation to understand the resistance of other parasites identified in this study.

IN-VIVO ANTHELMINTIC AND TOXICITY STUDY OF CRUDE EXTRACTS OF PROSOPIS AFRICANA AGAINST HAEMONCHUS CONTORTUS IN GOATS

In-vivo anthelmintic and toxicity study of Prosopis africana against Haemonchuscontortusin goats were evaluated for maximum tolerated dose (MTD) and therapeutic dose (TD) in this experiments. Two extracts, aqueous extract of stem bark (AESB) and aqueous extract of leaves (AELF) were obtained. Phytochemical constituents identified in the extracts include Tannins, Flavonoids, Alkaloids, Steroids, Cardiac glycosides and Saponins. In maximum tolerated dose and acute toxicity study, eighteen West African Dwarf goats (aged 5-6 months old) were used. Three dose regimes of 1000 mgkg-1, 2000 mgkg-1and 3000 mgkg-1body weight for each type of extract was orally administered to three goats per dose with each dose being replicated thrice. Animals were observed for 48 hours for apparent signs of toxicity. Four weeks later they were re-examined for signs of delayed cytotoxic effects. At the same time, the goats were evaluated for egg per gram reduction. The results shows at the dose of 1000 mgkg-1, there was no mortality and no evidence of toxicity in both gross and histopathological lesions. At the dose of 2000 mgkg-1to 3000 mgkg-1, various histopathological changes were observed, and at 3000 mgkg-1 stem bark, showed highest reduction (94.2 %) in egg per gram. In this study, 1000 mgkg-1 and 3000 mgkg-1are considered as MTD and TD respectively.

Immunoprotection Efficacy of Con A-Purified Proteins against Haemonchus contortus in Goats.

Parasitic nematodes are important pathogens that infect animals, causing significant economic losses globally. Current repeated treatments have led to widespread anthelmintic resistance in nematode populations, so vaccine development offers an alternative control approach. However, only one effective vaccine (named Barbervax) has been developed to protect animals against one of the most pathogenic nematodes of ruminants-Haemonchus contortus (the barber's pole worm). This vaccine contains a dominant component, Concanavalin A (Con A) purified H11 antigen, which has been shown to induce high levels (>85%) of immune protection in sheep breeds, but in goat breeds, the immunoprotection test of this native protein is still lacking. Here, we evaluated the protective efficacy of low-dose Con A-purified proteins for controlling the H. contortus infection in goats. Four-month-old Boer goats were equally divided into two vaccinated groups of 5 μg and 10 μg native proteins, and one adjuvant control. Each goat was immunized subcutaneously thrice and then challenged with 7000 infective third-stage larvae (L3s). The fecal egg count (FEC), degree of anemia, antibody levels of serum and abomasum mucosa, as well as worm burdens, were detected in experimental goats. Our results showed that both 5 μg and 10 μg vaccinated groups induced the effective protection in goats, reduced mean FEC by 71.8% and 68.6%, and mean worm burdens by 69.8% and 61.6%, respectively, compared to the adjuvant control. In addition, we detected that the serum antibody responses to the Con A-purified proteins were dominated by the IgG subtype, but the mucosal antibody responses were not detected. These data demonstrate Con A-purified proteins induced effective immunoprotection in goats, and underline their significance for controlling this widespread parasite.

Effects of Ferula asafetida, closantel, albendazole, oxfendazole, and ivermectin against Haemonchus contortus in goats and sheep.

Haemonchosis is a fatal disease of small ruminants caused by the parasite Haemonchus contortus (H. contortus). The most common drugs used in the treatment of H. contortus include albendazole, oxfendazole, and ivermectin. However, as previously reported in the treatment of haemonchosis, these medicines have acquired drug resistance problems over time. Interestingly, natural plant compounds have demonstrated promising effects in the treatment of H. contortus. Therefore, the current study evaluated the effects of plant extract, Ferula asafetida, against common drugs such as albendazole, oxfendazole, ivermectin, and closantel for the treatment of haemonchosis in small ruminants. The current study was conducted on different small ruminant farms in Kasur District, Punjab, Pakistan. The positive animals (n = 720) after coprological examination were selected in this study and divided into two major groups (n = 360 goats and n = 360 sheep). Further, animals were divided into five treatment groups (A-E) and one control group with no treatment (F). Albendazole, oxfendazole, ivermectin, closantel, and Ferula asafetida were administered orally to groups A-E, respectively. The eggs per gram feces (EPG) were determined through the McMaster technique on days 0, 7th, and 14th of treatment. The results showed a significantly higher efficacy of closantel and Ferula asafetida against H. contortus in both goats (100% and 70%; p < 0.05) and sheep (99% and 87%; p < 0.05), respectively. No correlation was observed between EPG reduction with age and gender in both goats and sheep. Allopathic drug closantel and herbal drug, Ferula asafetida, have been proved an effective dewormer against H. contortus in small ruminants.

Epidemiology of strongyle nematode infections and first report of benzimidazole resistance in Haemonchus contortus in goats in South Darfur State, Sudan

BackgroundSince pastoralists in South Darfur, Sudan, had complained about lack of albendazole (ABZ) efficacy to control nematodes in goats, the frequency of infection with gastrointestinal helminths was studied before in vivo faecal egg count reduction tests (FECRT) were conducted using ABZ orally either at the dose recommended for sheep, 5 mg/kg body weight (bw) or at 10 mg/kg bw. Experiments included goats naturally infected with gastrointestinal nematodes or experimentally infected with local Haemonchus contortus isolates. Three study areas (Nyala, Beleil and Kass) were visited in autumn or winter.ResultsOut of 478 screened goats, 82.4% were infected with gastrointestinal helminths and 82% were shedding eggs of strongyle nematodes with 90% of the strongyle larvae representing Haemonchus spp. A FECRT using naturally infected goats (n = 225: 71 untreated, 104 and 50 treated with 5 and 10 mg ABZ/kg bw, respectively) detected reduced ABZ efficacy in Nyala and Kass. Paired and unpaired FECRT calculations detected reductions of 72–92% with samples taken at 8 days post treatment with 5 mg ABZ/kg bw and of 85–94% with 10 mg ABZ/kg bw. The FECRT based on day 14 post treatment samples showed reductions of 69–77% with 5 mg/kg and of 75–87% with 10 mg ABZ/kg bw. In Beleil, ABZ efficacy was 95%. In the egg hatch test EC50 values for Nyala and Kass ranged from 0.12–0.24 μg thiabendazole/ml, corresponding to benzimidazole resistant phenotypes. Only Haemonchus spp. larvae were present after treatments in coprocultures. When the efficacy was evaluated experimentally using isolates of H. contortus from Nyala and Kass, the 5 mg ABZ/kg dose revealed reductions of 76–78% on day 8 and of 62–70% on day 14 with the unpaired method. Using 10 mg ABZ/kg, the FECR was still only 77–82%.ConclusionsBoth, in vivo and in vitro methods detected resistant H. contortus populations in goats from South Darfur State. The time point 14 days post treatment was more sensitive for detection of ABZ resistance than 8 days post treatment. This is the first report on the occurrence of anthelmintic resistance in Sudan confirming that anthelmintic resistance selection is occurring in African subsistence farming systems.

Supplementation with rumen-protected proteins induces resistance to Haemonchus contortus in goats

Resistance to gastro-intestinal nematode (GIN) in small ruminant is expected to arise from protein-rich rather than from energy-rich feeds. The objective of this study was to investigate the effect of the quality of the dietary proteins on the response of Creole goats to Haemonchus contortus. Three diets were compared: no supplementation (Hay: hay ad libitum), Control supplement (CS: hay ad libitum +2% BW of CS at 70 g of by-pass proteins/kg) and supplement enriched in rumen-protected proteins (RPP: hay ad libitum +2% BW of RPP at 139 g of by-pass proteins/kg). The FEC (faecal eggs counts) and the TFEC (total faecal eggs excreted/day) were significantly lower in the RPP. No difference was found between the supplemented diets for the total number of nematodes, but the RPP reduced the parasite prolificacy. The highest IgA responses were observed in animals with the highest nematode burden (Hay compared with CS diets). However, while the FEC and the TFEC were lower in animals feed with the RPP the IgA response were similar to those of the Hay. The IgA response that control GIN egg production in sheep could be one mediator of the resistance to H. contortus induced with by-pass proteins in goats.

Molecular detection of benzimidazole resistance levels associated with F167Y and F200Y polymorphisms in Haemonchus contortus of goats from Mozambique.

Benzimidazole (BZ) resistance of Haemonchus contortus has been associated with single nucleotide polymorphisms (SNPs) in codons 200 (F200Y) and 167 (F167Y) and, to a lesser extent, in codon E198A, of the β-tubulin isotype 1 gene. The present study was undertaken to survey the status of BZ resistance in naturally infected goats in smallholder farms in southern Mozambique by real-time PCR (qPCR) using TaqMan® assays. H. contortus-infective larvae (L3; n = 432) from 12 populations were individually genotyped for F200Y and F167Y SNPs to detect BZ resistance. For the F200Y SNP, the results revealed an overall mean percentages of 18.8% homozygous resistant (RR), 47.8% homozygous susceptible (SS) and 33.4% heterozygous (RS) H. contortus. For the F167Y SNP, the overall mean percentages were 1.6% RR, 94.9% SS and 3.5% RS. The percentage of resistant alleles (%R) for the F200Y and F167Y SNPs was 35.7 and 3.4%, respectively. Genotype combinations of the two mutations indicate resistant percentages ranging from 0.0 to 52.9%. From the four herds with high RR individuals, three farms dewormed the animals monthly, while the fourth farm dewormed the animals every 3months. In farms where animals were dewormed every 6months, low percentages of RR individuals were found, whereas no RR individuals were discovered in herds where animals were dewormed annually. These results suggest that the F200Y SNP is more significant in BZ resistance development of the surveyed population compared with the F167Y SNP.

Comparing the efficacy of copper oxide wire particles, copper sulfate and levamisole on Haemonchus contortus in goats

Haemonchus contortus is a primary concern for goat producers. An infestation of H. contortus, known as haemonchosis, can cause poor development, poor performance, and death. Due to the development of anthelmintic resistance, alternative ways to monitor and control haemonchus have been researched. Alternatives treatments to chemical anthelmintics are copper oxide wire particles (COWP) and copper sulfate (CuSO4). These have been found to be effective at controlling H. contortus populations in goats with a lessened resistance development, and are beginning to be used alongside chemical anthelmintics to combat resistance development in H. contortus. This study was performed to compare the effectiveness of COWP vs CuSO4 vs Levamisole.

Immune response in goats vaccinated with thiol-binding proteins from Haemonchus contortus.

The experimental protocol of immunization tested here confirms its protective effect against Haemonchus contortus in goats. This protection translated into a 65.5% mean reduction in adult worm burden after a homologous challenge, and a significant decrease (73.2%) in cumulative faecal egg counts (FECs). These parasitological findings were consistent with the levels of some biopathological parameters. Thus, the reduction in adult worms and FEC observed in immunized animals were associated with increased levels of packed cell volume as well as plasma proteins. This response seems to be related to an important increase in specific antibodies (in serum and gastric mucus) and eosinophilia in response to challenge. At the local level, a cellular response was also observed in which CD4+ lymphocytes and globule leucocytes played a predominant role. Finally, it should be noted that the study of immunolocalization of proteins used in the vaccination trial suggests that these antigens have an internal location (at intestinal and reproductive tissues) in the adult worm. This observation, in conjunction with the kinetics of specific antibody levels after the challenge, suggests that these antigens may be part of excretory/secretory (E/S) products.

Epidemiology and seasonal dynamics of adult Haemonchus contortus in goats of Aligarh, Uttar Pradesh, India.

A survey was carried out to determine the prevalence and seasonal abundance of Haemonchus contortus in the semi arid zone of Uttar Pradesh, India between January 2010 to December 2013. Entire gastrointestinal tract from slaughtered goats were brought to the laboratory. Parasites were collected from the abomasum, counted and recorded on monthly basis. The collected data were analyzed on the basis of temperature, rainfall and humidity of the months/seasons. Out of total 635 goats, 383 (60%) were found to be infected with H. contortus. The mean intensity and abundance was found as 354 and 263 respectively. Marked variations in the prevalence, mean intensity and abundance were noticed during different month/season of the year. Highest values of these infection indices were found in the rainy season and lowest in summer. Although prevalence, intensity and abundance were positively correlated with temperature, rainfall and humidity but only the effect of rainfall was found to be statistically significant. The present study provides a consolidated account on the seasonal dynamics of H. contortus, which can be used for integrated control measures of this blood sucking parasite under local environment conditions.

Prevalence of Haemonchus contortus in Goats of Western Chitwan of Nepal

The research was done in cross sectional design to study about the prevalence of Haemonchus contortus in goats of Western Chitwan of Nepal. A total of 252 fecal samples were collected through purposive sampling. Fecal samples were examined through sedimentation and floatation method. Egg per gram (EPG) was calculated through Mac Master Counting Technique of positive samples. Total prevalence was found to be 13.89%. Infection of parasite was more prevalent in males (15.18%) than in female (12.86%) but was statistically non-significant (P&gt;0.05). In non-dewormed goats (40.32%), the prevalence was significantly (P&lt;0.05) higher than in dewormed goats (5.26%). The results regarding the relationship between different age groups of goats and H. contortus showed that highest prevalence (14.54%) of parasite was observed in age group of below 1 year and the lowest (12.96%) in age group of above 2 year, statistically non-significant (P&gt;0.05). Maximum goats were found with medium level of infestation through EPG. This study shows higher prevalence of Haemonchus in non-dewormed than in dewormed goats which is statistically significant at (P&lt;0.05). Thus, effective deworming programme and management must be maintained in order to upgrade the health status and maximize the benefits from the animal.Int. J. Appl. Sci. Biotechnol. Vol 5(3): 321-325

Status of benzimidazole resistance in Haemonchus contortus of goats from different geographic regions of Uttar Pradesh, India

Present study was designed to survey the status of benzimidazole (BZ) resistance in goat flocks of different agro climatic regions of Uttar Pradesh (U.P.), India by faecal egg count reduction test (FECRT) and allele specific PCR (AS-PCR). Faecal egg counts and larval culture were made from representative samples of all regions. The results of the faecal culture and PCR-RFLP on beta tubulin isotype-1 gene showed Haemonchus contortus was predominant species. FECRT results showed BZ resistance prevalent in all regions. However, six farms of twenty screened, harboured susceptible populations of strongyles. Three hundred H. contortus infective larvae from all regions of the state were genotyped for BZ resistance. AS-PCR results revealed 55–85% of H. contortus homozygous resistant (rr), 10–21% homozygous susceptible (SS) and 5–24% heterozygous (rS) among different regions of U.P. The allele frequencies were 67–87.5% for resistant (TTC) and 12.5–33% for susceptible (TAC). The survey indicated that the status of BZ resistance is in alarming conditions in all the parts of the state.

Effect of sericea lespedeza leaf meal pellets on adult female Haemonchus contortus in goats

Sericea lespedeza (SL; Lespedeza cuneata) is a perennial warm-season forage rich in condensed tannins (CT) that has been reported to have anthelmintic activity against small ruminant gastrointestinal nematodes (GIN), particularly Haemonchus contortus, a highly pathogenic blood-feeder, but the mechanism of action of CT against H. contortus is not clearly understood. An experiment with young goats was designed to study the effect of SL leaf meal pellets on (1) a mature H. contortus infection, and (2) the surface appearance of adult H. contortus female worms. Thirty-six female and castrated male Boer crossbred goats artificially infected with H. contortus larvae were fed 75% SL leaf meal pellets or alfalfa pellets (18 goats/treatment group) in a 28-day confinement feeding trial. Fecal and blood samples were collected weekly for fecal egg count (FEC) and packed cell volume (PCV) determination, respectively, and all goats were slaughtered at the end of the trial for adult GIN recovery and counting. Five adult female H. contortus were recovered from the abomasum of two goats from each treatment group and from a prior study in which 75% and 95% SL leaf meal pellets or a commercial feed pellet were group-fed to grazing goats (270 days old, Spanish males, 10/treatment group) at 0.91kg/head/d for 11 weeks. Adult GIN collected were fixed and examined for evidence of surface damage using scanning electron microscopy. Feeding 75% SL pellets to young goats in confinement reduced (P<0.05) FEC compared with control animals, while total worm numbers and PCV were not influenced by treatment. Three out of the 5 adult H. contortus recovered from SL treatment goats in the confinement feeding trial had cuticular surface damage, while no damage was observed on worms from the control group. All five worms observed from both SL treatments in the grazing study showed a shrunken, disheveled cuticular surface, whereas this was not observed on worms from control animals. Overall, this work suggests that a possible mechanism of action of SL against female H. contortus in the animal's abomasum is a direct action of CT on the cuticle of the worm.

In vivo anthelmintic activity of Phytolacca icosandra against Haemonchus contortus in goats

The in vivo anthelmintic (AH) activity of the ethanolic extract from leaves of Phytolacca icosandra was evaluated in goats artificially infected with Haemonchus contortus. Parasite naïve goats were artificially infected with 3000 H. contortus infective larvae per animal. Once the infection was patent (day 28 post-infection) all the animals were sampled to determine the faecal egg counts (FEC) for five consecutive days. Two groups of animals were formed balanced for their FEC and body-weight (BW) (n=6/group): the non-treated control group and the treated group in which goats were individually administered with the ethanolic extract of P. icosandra. The extract was administered orally using gelatin capsules (250mg/kg BW) which were dosed on two consecutive days using a pill-dispenser. Faecal samples were collected from each animal from the day of dosage (Day 0) on a daily basis to determine the number of eggs per gram of feces (EPG) for 15 days post-treatment (PT). The FEC of the two groups were compared using the repeated measures analyses of variance using the log transformed data Ln (FEC+1). The presence of saponins, coumarins, flavonoids, steroids and terpenoids were detected by standard methodologies in the extract. The P. icosandra ethanolic extract was further analyzed by gas chromatography (GC) coupled to a mass spectrometry (GC-MS). A significant reduction in FEC was observed in the treated group compared to the control from day 7 until day 15 PT (P<0.05). The highest percentage reduction (72%) was found on day 11 PT. No adverse reactions were observed in all treated animals for the entire trial. The GC-MS analysis of the organic extracts revealed the presence of three fatty acids as compounds with highest abundance. The three compounds that were identified by their mass fragmentation patterns were: 2-Pentadecanone, 6, 10, 14-trimethyl (RT 10.3min), Pentadecanoic acid, 14-methyl-, methyl ester (RT 10.8min) and Hexadecanoic acid, ethyl ester (RT 11.2min). It is concluded that the P. icosandra ethanolic extract obtained from leaves showed in vivo anthelmintic activity against H. contortus when administered orally to goats at a dose of 250mg/kg BW on two consecutive days. The dose used did not cause any negative effects on the health of goats.

Maternal transference of passive humoral immunity to Haemonchus contortus in goats

This study evaluated the transference of maternal-specific antibodies against Haemonchus contortus and the humoral immune response of 32 goat kids to natural infection by the parasite, from birth to 5 months of age. All serum samples collected immediately after birth and before colostrum ingestion were negative for H. contortus antibodies, as demonstrated by ELISA. However, 30 and 60 days after colostrum and milk ingestion, antibody detection was positive and faecal egg count (FEC) was negative, suggesting the transference of humoral immunity by colostrum. All animals were FEC-negative for Strongylodea until four months of age, consistent with the stage of animal development where nourishment comes only from breastfeeding. Animals also presented a high serum IgA concentration, associated with lower levels of total IgG. This work demonstrated that passive humoral immunity against H. contortus in goat kids occurs via the colostrum and not by transplacental transference of antibodies.

Evaluation of Anthelmintic Effect of Neem (Azadirachta indica)Leaves on Haemonchus contortus in Goats

Evaluation of Anthelmintic Effect of Neem (Azadirachta indica)Leaves on Haemonchus contortus in Goats

Accuracy of an anaemia scoring chart applied on goats in sub-humid Kenya and its potential for control of Haemonchus contortus infections

We tested the practical application of an anaemia scoring chart (the FAMACHA © chart) as a method for controlling Haemonchus contortus in goats kept under smallholder conditions in a sub-humid area of Central Kenya. The objectives were: (1) to test the accuracy of the FAMACHA © chart in identifying anaemic goats (PCV ≤ 18); (2) to quantify the proportion of goats left untreated at farm level when using the chart. On each of two farms, Small East African goats of various ages were allocated to two treatment groups; a FAMACHA © group (F1 ( n = 34) and F2 ( n = 31) on farms 1 and 2, respectively) and a control group (C1 ( n = 34) and C2 ( n = 30)). In F1 and F2 goats with a FAMACHA © score of 3, 4 or 5 were treated with anthelmintic after scoring. In C1 and C2 goats were treated every 4 weeks from 15 February to 20 July. Every 2 weeks all goats were scored with the FAMACHA © chart and weighed. Furthermore, faecal samples were collected for faecal egg counts (FEC) and blood samples were collected for packed cell volume (PCV) determination. H. contortus was found to be the predominant nematode on both farms. The mean FECs were higher on farm 1 compared to farm 2, while in contrast the mean PCV levels were lowest on farm 2. The latter was most likely due to the presence of Fasciola spp., flea and tick infections on farm 2. The accuracy of the chart was evaluated by using PCV as the gold standard for anaemia (PCV ≤ 18%). The mean percentage of false-negative scorings per sampling was 0.7% on farm 1 and 1.6% on farm 2, while the mean percentage of false-positive scorings was 9.7% and 21.4%, respectively. It is most likely that the accuracy of the chart was negatively affected by the concurrent parasite infections on farm 2. The mean proportion of untreated goats per sampling was 89% and 77% on farm 1 and farm 2. It was concluded that the FAMACHA © chart can be a valuable tool for decision-making in control of H. contortus in goats kept under smallholder conditions, without morbidity or mortality unacceptable to the farmer. The application may further reduce the risk of development of anthelmintic resistance by increasing refugia. However, caution should be taken under conditions where other anaemia-causing parasites are present (e.g. Fasciola spp. and ecto-parasites), since this possibly decreases the accuracy of the FAMACHA © chart.

Lack of effects of quebracho and sainfoin hay on incoming third-stage larvae of Haemonchus contortus in goats

The effects of tannins on adult populations of Haemonchus contortus, Trichostrongylus colubriformis and Teladorsagia circumcincta in goats are characterised mainly by a decrease in egg excretion without any significant changes in worm number. In contrast, the impact of tannins on T. colubriformis or T. circumcincta third-stage larvae (L3) is associated with a significant reduction in worm establishment. The objective of the present study was to examine the effects of quebracho extract tannins on H. contortus L3. The consequences of consumption of sainfoin hay were also examined. Twenty-one naïve kids were divided into three experimental groups. Group Q received quebracho extract and group S received sainfoin hay from days D3 to D5. Group C remained as an infected control group. All kids received 1500 L3 H. contortus on D0, D1 and D2. On D18, post-infection, the kids were slaughtered and the worm populations compared in the different groups. Compared to the control values, the worm counts decreased, respectively, by 33% and 38% in groups Q and S but the differences were not significant. No differences were found in pathophysiological measurements between the three groups. The results confirm differences in tannin effect according to nematode species but not parasitic stage.

Epidemiology/grazing management

A dynamic and innovative approach to managing the blood-consuming nematode Haemonchus contortus in goats is critical to crack dependence on veterinary anthelmintics. H. contortus management strategies have been the subject of intense research for decades, and must be selected to create a tailored, individualized program for goat farms. Through the selection and combination of strategies from the Toolbox, an effective management program for H. contortus can be designed according to the unique conditions of each particular farm. This Toolbox investigates strategies including vaccines, bioactive forages, pasture/grazing management, behavioural management, natural immunity, FAMACHA, Refugia and strategic drenching, mineral/vitamin supplementation, copper Oxide Wire Particles (COWPs), breeding and selection/selecting resistant and resilient individuals, biological control and anthelmintic drugs. Barbervax®, the ground-breaking Haemonchus vaccine developed and currently commercially available on a pilot scale for sheep, is prime for trialling in goats and would be an invaluable inclusion to this Toolbox. The specialised behaviours of goats, specifically their preferences to browse a variety of plants and accompanying physiological adaptations to the consumption of secondary compounds contained in browse, have long been unappreciated and thus overlooked as a valuable, sustainable strategy for Haemonchus management. These strategies are discussed in this review as to their value for inclusion into the ‘Toolbox’ currently, and the future implications of ongoing research for goat producers. Combining and manipulating strategies such as browsing behaviour, pasture management, bioactive forages and identifying and treating individual animals for haemonchosis, in addition to continuous evaluation of strategy effectiveness, is conducted using a model farm scenario. Selecting strategies from the Toolbox, with regard to their current availability, feasibility, economical cost and potential ease of implementation depending on the systems of production and their complementary nature, is the future of managing H. contortus in farmed goats internationally and maintaining the remaining efficacy of veterinary anthelmintics.