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

BACKGROUND: 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. METHODOLOGY: 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. RESULTS: 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. CONCLUSION: Allopathic drug closantel and herbal drug, Ferula asafetida, have been proved an effective dewormer against H. contortus in small ruminants.

In vitro nematocidal activity of commercial fatty acids and ß-sitosterol against Haemonchus contortus.

Haemonchus contortus is a haematophagous gastrointestinal nematode (GIN) that causes severe anaemia and even death in small ruminants, negatively impacting the economic viability of farms. Traditionally, this parasite has been controlled with chemical compounds; however, inadequate use of these types of products has favoured the emergence of anthelmintic resistance. Therefore, it is necessary to search for alternatives for GIN control. Previous studies have reported the anthelmintic activity of edible mushroom extracts against H. contortus. A recent study reported that a fraction constituted of different fatty acids and ß-sitosterol isolated from the basidiomata of the edible mushroom Pleurotus djamor ECS-123 has ovicidal and larvicidal activity against H. contortus. Thus, this study aimed to assess the anthelmintic activity of the pure molecules: pentadecanoic acid, palmitic acid, ß-sitosterol, stearic acid and linoleic acid. For this purpose, an egg-hatching inhibition test was carried out in which the compounds were evaluated individually and in combination at a final concentration of 20 mg mL-1. Furthermore, larval mortality was assessed using a combination of the five commercial compounds previously mentioned at different concentrations (1.25-20 mg mL-1). Palmitic acid and stearic acid, in some combinations, inhibited H. contortus egg hatching by 100%. On the other hand, in the larval mortality test, the combination of the five compounds showed dose-dependent behaviour, and 100% mortality was obtained 24 h post-incubation. Pure molecules and their combinations have anthelmintic-like activity against the eggs and larvae of H. contortus.

Ovine haemonchosis: a review.

Sheep farming is the backbone of a rural economy in developing countries, and haemonchosis is a major impediment in the way of its progress. Haemonchus contortus (H. contortus) infection persists all over the world particularly in the tropical and sub-tropical regions. Various review articles have been published to substantially cover one or more aspects of its morphology, prevalence, pathogenesis, symptoms, diagnosis, immune response, drug resistance, treatment, and control measure. The objective of this paper is to briefly review past and present information available in the aforementioned areas in one place to enable the readers to fully understand the problem from a broader perspective. H. contortus parasite harbours in abomasum of affected animal and feeds on its blood, producing mild to severe symptoms and even death in acute form. The parasite thus inflicts heavy production losses and is of economic importance. H. contortus has developed diverse characters over the years leading to limited success in the production of vaccines. Indiscriminate use of the anthelmintics has produced drug resistance against almost all conventional products. Efficacy of medicinal plants and non-conventional chemicals has been reported under controlled experiments; however, research on their adverse effects on growth and fertility is yet to be studied. Research on molecular tools for identification and introduction of resistant genes into the flock is also underway but still a long journey to find its field application. Crossbreeding may compromise the production traits of the existing flock. In given circumstances, a targeted selective treatment approach along with selective breeding, culling of more susceptible animals, and maintaining a good body condition score through the provision of a balanced diet remains a workable strategy to control haemonchosis in sheep.

Immunization with recombinant rHc23 partially protects lambs against trickle infections by Haemonchus contortus.

BACKGROUND: Haemonchosis is one of the most economically important parasitic diseases affecting small ruminants all over the world. Chemotherapeutic control has several shortcomings (limited anthelmintic arsenal, frequent resistance) and is hardly affordable by many farm economies. A recombinant antigen (rHc23) was shown to induce significant protection in vaccination trials with single dose challenges and different adjuvants. RESULTS: Lambs were vaccinated with 100 µg rHc23/dose + bacterial immunostimulant (BI) (LPS from Escherichia coli + Propionibacterium acnes extract) (days - 2, 0, 7 and 14) and subjected to a trickle infection with two dosages [6x, 1000 infective larvae (L3) or 6x, 2000 L3]. Vaccinated lambs showed a significant antibody response against rHc23 and Haemonchus contortus soluble extract as assessed by ELISA and Western blot (WB). Fecal egg counts (epg) along the experiment of vaccinated and BI treated lambs were significantly reduced. All vaccinated animals showed total egg output and abomasal helminth burdens (median, average) lower than those from unvaccinated or BI-treated animals lambs although differences were not statistically significant. CONCLUSIONS: Vaccination with 100 µg rHc23/dose + BI against H.contortus trickle infections apparently induced lower epg values and helminth burdens at the end of the experiment. Intragroup individual variations did not allow to obtain conclusive results and more research is needed including adjuvants and larger groups of animals to validate the potential value of rHc23 as candidate to develop a recombinant vaccine for lambs haemonchosis.

In vitro ovicidal activity of Baccharis conferta Kunth against Haemonchus contortus.

The indiscriminate use of chemical drugs to deworm livestock tends to trigger an anthelmintic resistance problem. In this context, the use of plant extracts rich in secondary metabolites could be an alternative method for the control of gastrointestinal nematodes. Baccharis conferta Kunth is a native plant species from Mexico that is widely used by several ethnic groups as forage for farm animals and medicinally to treat gastrointestinal diseases such as acute stomach ache, dysentery, diarrhoea, vomiting, indigestion, colic, intestinal spasms, urinary problems, and cramps. The aim of the present study was to isolate and characterise the ovicidal constituents of B. conferta and to determine a possible mode of action against Haemonchus contortus. The ovicidal activity was determined using the egg hatching inhibition test (EHI) to assess the methanol extract obtained from B. conferta foliage. The dry extract was partitioned (water/ethyl acetate) to obtain an ethyl acetate (BcEtOAc-F) and aqueous fraction. BcEtOAc-F showed an ovicidal activity of 72.32% EHI at 1 mg/mL. The chromatographic fractionation of BcEtOAc-F resulted in three active sub-fractions with higher ovicidal activity: BcC1R4 (99.15% EHI at 1.0 mg/mL); BcC1R5 (92.51% EHI at 0.75 mg/mL); and BcC1R8 (96.8% EHI at 3.0 mg/mL). Chemical analysis of the BcC1R4 fraction allowed the identification of the major active compound, isokaempferide (1, 98.06% EHI at 1 mg/mL). While, 4,5-di-O-acid caffeoylquinic (3; 96.8% EHI at 3 mg/mL) and an inactive flavone (vicenin-2, 2) were identified as the main compounds in BcC1R8. Chemical characterisation of the isolated compounds was performed via spectroscopic (NMR) and spectrometric (UPLC-MS) analyses. Additionally, the environmental and confocal scanning microscopy analyses revealed that isokaempferide was able to cross the eggshell layer without breaking it and attach itself to the embryo, causing its death. The flavonol, isokaempferide, and the hydroxycinamic acid, 4,5-di-O-caffeoylquinic, displayed powerful ovicidal effects, proving to be a potential alternative for the development of a phytodrug for the control of haemonchosis.

A new thioredoxin reductase with additional glutathione reductase activity in Haemonchus contortus.

We report, herein, the purification to homogeneity and the biochemical and kinetic characterization of HcTrxR3, a new isoform of thioredoxin reductase (TrxR) from Haemonchus contortus. HcTrxR3 was found to have a relative molecular weight of 134,000, while the corresponding value per subunit obtained under denaturing conditions, was of 67,000. By peptide mass spectrophotometric analysis, HcTrxR3 was determined to have 99% identity with the H. contortus HcTrxR1 although, and most importantly, they are different in their amino acid sequence in two amino acid positions: 48 (isoleucine instead of leucine) and 460 (leucine instead of proline). The enzyme catalyzes NADPH-dependent reduction of DTNB and, unexpectedly, it follows the pattern of glutathione reductases (GR) performing the reduction of oxidized glutathione (GSSG) to reduced glutathione using NADPH as the reducing cofactor. Hence, it is important to highlight this enzyme's new and unexpected condition that makes so special and one our main finding. Enzyme Kcat values for DTNB, GSSG and NADPH were 12, 3 and 8 s-1, respectively. HcTrxR3 developed, into specific TrxR substrates: ebselen and sodium selenite, with activity at 0.5 and 0.068 (U/mg), respectively; and 0.044 (U/mg) for S-nitrosoglutathione through its GR activity. The enzyme was inhibited by gold compound auranofin (AU), a selective inhibitor of thiol-dependent flavoreductases. Although HcTrxR3 has both TrxR and GR activity as thioredoxin glutathione reductase (TGR) does, it is a TrxR because it has no glutaredoxin domain and it does not develop any hysteretic behavior as does TGR. The importance of this new enzyme is potential to further clarify the detoxification and haemostasis redox mechanism in H. contortus. Likewise, this enzyme could also be a protein model to recognize more differences between TrxR and GR.

Molecular identification of Haemonchus contortus in sheep from Upper Egypt.

Introduction: Haemonchus spp. are considered the most important strongylid nematodes with a worldwide distribution. The parasite's blood-sucking nature can lead to severe anemia in infected animals. Despite its widespread impact, there is a dearth of comprehensive data on morphological and molecular identification methods for Haemonchus spp. in sheep from Upper Egypt. To address this gap, our current study aimed to assess the prevalence of Haemonchus spp. in 400 sheep fecal samples. Methods: We employed microscopic examination and molecular techniques, using polymerase chain reaction (PCR) targeting the 18S gene for precise identification. Additionally, the potential risk factors associated with the infection by the parasite in sheep were explored. Results: The study pointed out that 33.00% (132 of 400) of the examined sheep were infected with Haemonchus spp. Sheep age and seasonal variability were found to be significant factors (p < 0.05) associated with the infection. Notably, sheep under 2 years old exhibited a higher risk, with an infection rate of 43.75% (84 out of 192), than their older counterparts. Furthermore, all reported infections were exclusively observed during the cold season, constituting 58.93% (132 out of 224) of cases. By contrast, no statistically significant association (p > 0.05) was found between the sex of the examined sheep and the occurrence of haemonchosis. Employing molecular methods, we isolated and identified the parasite through PCR analysis of cultured larvae, which were then subsequently confirmed as Haemonchus contortus via phylogenetic analysis. Discussion: The study concluded that there was a relatively high occurrence of H. contortus among sheep from Upper Egypt. We recommend the implementation of stringent and effective control measures to combat the infection and safeguard livestock health.

In vitro ovicidal effect of p-coumaric acid from Acacia bilimekii aerial parts against Haemonchus contortus.

Acacia bilimekii is a plant with a high content of protein, fibre, and condensed tannins, making it an excellent feed for small ruminants with anthelmintic potential. This study aimed to evaluate the ovicidal activity of a hydroalcoholic extract (Ab-HA) and fractions from A. bilimekii aerial parts on Haemonchus contortus. The ovicidal activity of the Ab-HA extract and its fractions obtained by chromatographic fractionation were evaluated through the egg hatching inhibition (EHI) test. The results showed that the Ab-HA extract had 91% EHI at 20,000 µg/mL with a mean effective concentration (EC50) of 9260 µg/mL. After liquid-liquid fractionation of Ab-HA extract, the aqueous fraction (Ab-Aq) did not show ovicidal activity, whereas the organic fraction (Ab-EtOAc) showed a better EHI than the Ab-HA extract (98.9% at 2500 µg/mL). Then, the chemical fractionation of Ab-EtOAc allowed obtaining six bioactive fractions (AbR12-17) with an EHI greater than 90% at 1500 µg/mL. The best treatment was AbR15 (98.7% EHI at 750 µg/mL). Chemical analysis by HPLC-PDA of AbR15 indicated the presence of p-coumaric acid and the flavone luteolin as major compounds. Additionally, the commercial p-coumaric acid standard was evaluated in the EHI assay and showed an EHI of 97% at 62.5 µg/mL. Meanwhile, the confocal laser scanning microscopy analysis demonstrated a colocalization effect between p-coumaric acid and the H. contortus embryonated eggs. These results indicate that due to their major chemical compounds (including p-coumaric acid), the aerial parts of the plant A. bilimekii, could be considered as natural potential tool for controlling haemonchosis in small ruminants.

Low-cost molecular methods to characterise gastrointestinal nematode co-infections of goats in Africa.

BACKGROUND: Veterinary diagnostics aid intervention strategies, track zoonoses, and direct selective breeding programs in livestock. In ruminants, gastrointestinal nematode (GIN) parasites are a major cause of production losses, but morphologically similar species limit our understanding of how specific GIN co-infections impact health in resource-limited settings. To estimate the presence and relative abundance of GINs and other helminths at the species level, we sought to develop a low-cost and low-resource molecular toolkit applied to goats from rural Malawi smallholdings. METHODS: Goats were subjected to health scoring and faecal sampling on smallholdings in Lilongwe district, Malawi. Infection intensities were estimated by faecal nematode egg counts with a faecal subsample desiccated for DNA analysis. Two DNA extraction methods were tested (low-resource magbead kit vs high-resource spin-column kit), with resulting DNA screened by endpoint polymerase chain reaction (PCR), semi-quantitative PCR, quantitative PCR (qPCR), high-resolution melt curve analysis (HRMC), and 'nemabiome' internal transcribed spacer 2 (ITS-2) amplicon sequencing. RESULTS: Both DNA isolation methods yielded comparable results despite poorer DNA purity and faecal contaminant carryover from the low-resource magbead method. GINs were detected in 100% of samples regardless of infection intensity. Co-infections with GINs and coccidia (Eimeria spp.) were present in most goats, with GIN populations dominated by Haemonchus contortus, Trichostrongylus colubriformis, Trichostrongylus axei, and Oesophagostomum columbianum. Both multiplex PCR and qPCR were highly predictive of GIN species proportions obtained using nemabiome amplicon sequencing; however, HRMC was less reliable than PCR in predicting the presence of particular species. CONCLUSIONS: These data represent the first 'nemabiome' sequencing of GINs from naturally infected smallholder goats in Africa and show the variable nature of GIN co-infections between individual animals. A similar level of granularity was detected by semi-quantitative PCR methods, which provided an accurate summary of species composition. Assessing GIN co-infections is therefore possible using cost-efficient low-resource DNA extraction and PCR approaches that can increase the capacity of molecular resources in areas where sequencing platforms are not available; and also open the door to affordable molecular GIN diagnostics. Given the diverse nature of infections in livestock and wildlife, these approaches have potential for disease surveillance in other areas.

Exploration of machine learning models to predict the environmental and remote sensing risk factors of haemonchosis in sheep flocks of Rajasthan, India.

Globally haemonchosis in sheep is a known devastating disease imposing considerable economic loss. Understanding the environmental risk factors and their role is essentially required to manage the disease successfully. In this study, 14 years' disease data was analysed to predict the risk factors responsible for the occurrence of the disease. Season-wise analysis revealed high incidence during monsoon and post-monsoon and least in winter and summer seasons. The linear discriminant analysis (LDA) revealed the significant environmental and remote sensing risk factors contributing to haemonchosis incidence as enhanced vegetation index, leaf area index, potential evapotranspiration and specific humidity. Further, significant ecological and environmental risk factors identified using LDA were subjected to the climate-disease modelling and risk maps were generated. Basic reproduction number (R0) was estimated and was ranged from 0.76 to 2.08 for >1000 egg per gram of faeces (EPG) in four districts whereas R0 values of 1.09-1.69 for >2000 EPG in three districts indicating the severity of the infection. The random forest and adaptive boosting models emerged out as best fitted models for both the EPG groups. The results of the study will help to focus on high-risk areas of haemonchosis in sheep to implement the available control strategies and better animal production globally.

Conjunctival mucous membrane colour as an indicator for the targeted selective treatment of haemonchosis and of the general health status of peri-urban smallholder goats in southern Malawi.

The world's growing population is becoming increasingly centred around large cities, affording opportunities for peri-urban food production. Goats are well-suited to conversion of resources that are available in peri-urban settings into meat and occasionally milk. Haemonchus contortus has been described as "the nemesis of small ruminant production systems in tropical and subtropical regions"; hence control of haemonchosis through planned animal health management affords a pragmatic first step in improving the production efficiency of peri-urban goats. This study of peri-urban goat production investigated the potential value of targeted selective treatment of haemonchosis. 452 peri-urban goat keepers in southern Malawi were visited during three seasonal periods with relevance to the epidemiology of haemonchosis. 622, 599 and 455 individually identified goats were clinically examined during the dry season, the rainy season, and shortly after the end of the rainy season, respectively. Data were recorded for sex, age, weight, conjunctival mucous membrane colour score (FAMACHA©), body condition score (BCS) and faecal worm egg count (FEC); and where possible for pregnancy and lactation status. Animals with pale ocular mucous membranes were treated with 10 mg/kg albendazole, then re-examined 14 days later. Animals with pink mucous membranes, but FECs ≥250 eggs per gram were also re-examined and treated 14 days later. The results show high variability in growth rates deduced from the ages and bodyweights of each of 999 goats at the time of their enrolment. FAMACHA© scores alone were a poor index for the targeted selective treatment of haemonchosis, because they failed to identify too many animals that would have required treatment at different times of year and using different FAMACHA© and FEC cut-offs. Combining the indices of FAMACHA© scores ≥4, body condition scores ≥2, and age >18 months was more reliable in identifying those animals requiring treatment when different epidemiologically-relevant FEC thresholds for different seasons were taken into account. Inclusion of late pregnancy or early lactation status would have resulted in very few animals requiring treatment being missed. The use of conjunctival mucous membrane colour scoring in this way provided a valuable insight of the general health status of the peri-urban goats, to create opportunities for planned animal health management to improve productivity. The efficacy of albendazole treatment was poor, putatively due to drug resistance, or poor drug bioavailability in goats. In summary, our study shows opportunities for better production efficiency in peri-urban goats, and demonstrates the value of simple clinical diagnostic indices as decision support tools in planned animal health management.

Repeated vaccination against Haemonchus contortus provides continuous protection to young grazing sheep.

Haemonchus contortus is the most important gastrointestinal nematode in the tropics and subtropics causing huge economic losses to the small ruminant industry. Vaccination is potentially a sustainable approach to control this parasite and the performance of Barbervax® a vaccine containing integral membrane glycoproteins from H. contortus intestinal cells, was evaluated in naturally infected grazing sheep during their development from sucking lambs to adults. The sheep were randomly assigned to two groups: Vaccine and Control. The Vaccine group were vaccinated 23 times over the course of this two-year trial at intervals of 3-6 weeks. They responded with anti-vaccine specific antibodies, had 80 % lower Haemonchus egg counts and were less anaemic compared with the controls. Packed cell volumes (PCV) were always greater than 25 % in the vaccinated sheep but averaged between 23 % and 24 % in the controls. Total plasma protein values were higher in the vaccinated group from the third vaccination until the end of the trial. Throughout the trial, 88 % of the control sheep were drenched (average of 3.1 drenches per treated animal) but only 57 % of vaccinates, needed a salvage anthelmintic treatment (average of 1.9 drenches per treated animal), however, between group no differences in body weight were observed. In summary, these results indicate that a continuous course of Barbervax® can provide lambs with substantial year-round protection against H. contortus until they reached adulthood.

Morada Nova sheep breed: Resistant or resilient to Haemonchus contortus infection?

Morada Nova is a Brazilian hair sheep breed that is well adapted to the country's mainly tropical climate and has good potential for meat and leather production. This breed is reported to be resistant to Haemonchus contortus infection, a highly desired characteristic due to the large impact of this parasite on sheep farming. Therefore, the present study aimed to characterize 287 recently weaned Morada Nova lambs and 123 ewes in relation to their resistance against H. contortus. The animals were dewormed and 15 days later artificially infected with 4000 H. contortus L3 (D0). They were individually monitored by periodic assessment of fecal egg count (FEC), packed cell volume (PCV), and live weight (LW). On D42, the sheep were again dewormed and submitted to a new parasitic challenge, following the same scheme. The animals of each category (lambs and ewes) were ranked according to individual mean FEC values, and classified as resistant (R, 20%), intermediate (I, 60%), or susceptible (S, 20%) to H. contortus infection. At weaning, high FEC were observed in all three phenotypes (P>0.05). After the artificial infections, there was a significant difference (P<0.05) among the three lamb phenotypes for the mean FEC (RI > S), and LW (R=I > S). The infection levels (FEC) were negatively correlated with PCV (r = -0.66; P<0.001), and LW (r = -0.30; P<0.001). Despite this, the lambs were resilient, since more than 88% of these animals maintained the PCV above 24%, even when heavily infected. The importance of selective parasite control before weaning to reduce the negative impact on slaughter weight was evidenced, taking into account the high positive correlation between LW at weaning and final LW (r=0.73; P<0.001). The ewes, in turn, were strongly resistant to the parasite. Despite highly significant differences (P<0.001) for mean FEC between phenotypes (R0.05). With the phenotypic characterization performed here, it is possible to introduce procedures for parasite control in Morada Nova flocks, facilitating the target-selective treatment approach. The results of this study can also support improvement of meat production by the Morada Nova breed.

Anthelmintic efficacy of trichlorfon and blood parameters of young lambs infected with Haemonchus contortus.

In this study we evaluated the efficacy of trichlorfon against Haemonchus contortus, monitoring its influence on blood parameters and plasma enzymes of lambs with haemonchosis. A lamb group was orally treated with trichlorfon at 100 mg kg-1 while the other group was untreated. Split-plot design analysis was performed with the lamb groups defined as plots while the subplots were the four periods (weeks) of collection. The trichlorfon treatment promoted a significant and effective reduction of fecal egg counts after one week, with efficacies > 99%. After 21 days of treatment, detected blood parameters and serum levels of plasma enzymes were normal. Additionally, serum albumin and urea concentrations increased to normal values, which were not observed in untreated lambs. The treatment with this organophosphate, using a correct oral administration, may represent an effective therapeutic alternative for sheep infected with multi resistant strain of H. contortus.

Morada Nova sheep breed: Resistant or resilient to Haemonchus contortus infection?

Morada Nova is a Brazilian hair sheep breed that is well adapted to the country's mainly tropical climate and has good potential for meat and leather production. This breed is reported to be resistant to Haemonchus contortus infection, a highly desired characteristic due to the large impact of this parasite on sheep farming. Therefore, the present study aimed to characterize 287 recently weaned Morada Nova lambs and 123 ewes in relation to their resistance against H. contortus. The animals were dewormed and 15 days later artificially infected with 4000 H. contortus L3 (D0). They were individually monitored by periodic assessment of fecal egg count (FEC), packed cell volume (PCV), and live weight (LW). On D42, the sheep were again dewormed and submitted to a new parasitic challenge, following the same scheme. The animals of each category (lambs and ewes) were ranked according to individual mean FEC values, and classified as resistant (R, 20%), intermediate (I, 60%), or susceptible (S, 20%) to H. contortus infection. At weaning, high FEC were observed in all three phenotypes (P > 0.05). After the artificial infections, there was a significant difference (P < 0.05) among the three lamb phenotypes for the mean FEC (R < I < S), PCV (R > I > S), and LW (R = I > S). The infection levels (FEC) were negatively correlated with PCV (r = -0.66; P < 0.001), and LW (r = -0.30; P < 0.001). Despite this, the lambs were resilient, since more than 88% of these animals maintained the PCV above 24%, even when heavily infected. The importance of selective parasite control before weaning to reduce the negative impact on slaughter weight was evidenced, taking into account the high positive correlation between LW at weaning and final LW (r = 0.73; P < 0.001). The ewes, in turn, were strongly resistant to the parasite. Despite highly significant differences (P < 0.001) for mean FEC between phenotypes (R < I < S), 98% of the ewes maintained FEC below 4000 EPG. Their health was not affected, since PCV and LW did not differ between phenotypes, and these parameters were not significantly correlated with FEC (P > 0.05). With the phenotypic characterization performed here, it is possible to introduce procedures for parasite control in Morada Nova flocks, facilitating the target-selective treatment approach. The results of this study can also support improvement of meat production by the Morada Nova breed.

Immune response against subclinical haemonchosis in Himalayan hill goats.

Haemonchosis commonly occurs as chronic and subclinical infection in small ruminants, and understanding of immunological response against subclinical haemonchosis is of paramount importance for designing and implementing effective control strategies. The present study was designed to evaluate immunological response during subclinical haemonchosis, experimentally established in goats. Sixteen 5-6 month-old helminth naive kids were randomly allocated into one of two groups, infected and uninfected; the infected group being infected per os with 250 Haemonchus contortus larvae per kg body weight. Faecal, blood and serum samples were collected every third day up to 30 days post-infection (DPI), thereafter weekly up to 58 DPI to record changes in faecal egg count (FEC), haemoglobin (Hb), packed cell volume (PCV), peripheral eosinophil percentage and immunological parameters, such as macrophage cytokine interleukin-12 (IL-12), Th1 cytokine (IFN-γ), Th2 cytokines (IL-4, 13, 25, 33) and immunoglobulins (IgG and IgE). Pre-patent period of H. contortus in the present study was 18 days and eggs per gram (EPG) peaked on 30 DPI. The total reduction in body weight gain in the infected group was 26 g per day when compared with uninfected animals. Hb (7.35 ± 0.34 g/dL in infected animals compared with 9.76 ± 0.67 in control animals) and PCV levels (22 ± 1.54 g/dL in infected animals compared with 29.2 ± 1.27 in control animals) decreased significantly up to 44 DPI in infected group (P = 0.000). IL-4, IL-13, IL-33, IgG and IgE showed significant increase in infected animals at different periods. IFN-γ, IL-12 and IL-25 did not show any significant changes barring a steep rise of IFN-γ on 27 DPI. A positive correlation was observed between IgE and IL-4 in subclinical haemonchosis. Of particular note was that all the major cytokines, such as IFN-γ (P = 0.000), IL-4 (P = 0.000), IL-13 (P = 0.009), and both IgG (P = 0.000) and IgE (P = 0.003), were observed at the lowest concentration on 24 DPI. The effect of infection was found to be significant on cytokines with a strong interaction with time. Taken together, the data suggest that Th2 immune response is predominating in subclinical haemonchosis. The economic loss in term of body weight gain due to subclinical haemonchosis was considerable.

Evaluation of the curative effect of Balanites aegyptiaca fruits ethanolic extract on Haemonchosis experimentally induced in Egyptian Baladi goats: phytoanalytical, parasitological and hematological studies.

This study aimed to screen phytochemical components and antioxidant activity of Balanites aegyptiaca ethanolic extract (BAF-EE) as well as to evaluate its curative effect on experimentally induced haemonchosis in goats. Phytochemical constitutes of BAF-EE were screened and identified using Gas Chromatography-mass Spectrometry (GC-MS) analysis and antioxidant effect was determined. Infective third larval stage (L3) of Haemonchus contortus (H. contortus) were obtained by culturing feces of goat harboring monospecific infection of the parasite. Twelve male goats were randomly divided into four groups (n = 3) as: G1 (infected-untreated) which served as control positive, G2 (infected-BAF-EE treated), G3 (infected-albendazole treated) and G4 (uninfected-BAF-EE treated) that served as control negative. Experimental infection was conducted with a single oral dose of 10,000 L3 at 0-time, whereas treatment with BAF-EE and albendazole were given at a single oral dose of 9 g and 5 mg/kg BW, respectively in the 5th week post infection (PI). Egg count per gram of feces (EPG) was conducted once a week and blood samples were drawn on zero time, 3rd week PI and then biweekly for 9 weeks, for conduction of hemogram. At the end of the experiment, all animals were slaughtered and adult worms in their abomasa were counted. GC-MS analysis confirmed 28 compounds in the extract which revealed presence of saponins, flavonoids, terpenoids, phenolics and alkaloids, and exhibited in vitro antioxidant activity. Clinical signs observed on the infected animals were signs of anemia, which were gradually disappeared post treatment (PT). A maximum reduction in EPG (88.10%) and worm burden (94.66%) was recorded on 4th week PT due to efficacy of BAF-EE in contrast to 98.29% and 96.95% efficacy of albendazole. All infected groups showed a significant decrease in hemoglobin (Hb) and packed cell volume (PCV) and presence of microcytic hypochromic anemia compared with G4. Goats treated with B. aegyptiaca and albendazole, exhibited significant increase in Hb and PCV 2 weeks PT and anemia changed to be normocytic hypochromic or microcytic normochromic in G2 and G3, respectively. Total white blood cells (WBCs) were elevated significantly in all infected groups which attributed to increase in lymphocytes, monocytes and eosinophils on expense of neutrophils. After treatments, WBCs and previously mentioned cells tended to decease. This study demonstrated that BAF-EE has anthelmintic effect against H. contortus and can improve hemogram and health condition of infected goats.

Trials with the Haemonchus vaccine, Barbervax®, in ewes and lambs in a tropical environment: Nutrient supplementation improves protection in periparturient ewes.

Haemonchus contortus is an economic problem in sheep farms worldwide, mainly in the tropics and subtropics. A vaccine against haemonchosis, called Barbervax®, was evaluated in ewes under two nutritional status, naturally infected with gastrointestinal nematodes. Ewes were divided into four groups: Supplemented Diet - Vaccine; Supplemented Diet - No vaccine; Basal Diet - Vaccine and Basal Diet - No vaccine. Their lambs were divided in Vaccinated and No vaccine. Ewes were immunised six times starting about 1 month of pregnancy with the first three doses at 3 week intervals and the last three shots at 4 week intervals. Supplemented ewes had higher body weight, body score and packed cell volume compared with those fed a basal diet. Both groups of vaccinated ewes showed a similar response in circulating anti-vaccine antibodies but the vaccine had no discernible effect on either body weight, body score and packed cell volume. There was a marked group difference in the number of ewes that received precautionary treatments with anthelmintic. All 14 Basal Diet - No vaccine ewes required treatment. In contrast only 7 ewes, in the Supplemented Diet - Vaccine group required anthelmintic treatment. In the Basal Diet - Vaccine and in the Supplemented Diet - No Vaccine groups, 12 and 13 ewes needed anthelmintic treatment, respectively. Vaccinated lambs showed much higher antibody titres resulting in 80% less Haemonchus spp. egg counts comparing with no vaccine lambs. Taken together these results clearly suggest that in pregnant and lactating ewes a combined protective effect between vaccination and improved nutrition resulted in fewer precautionary anthelmintic treatments. Thus, it was possible to achieve a more sustainable level of control of the haemonchosis, less dependent on anthelmintic drugs.

Responses of Sri Lankan indigenous goats and their Jamnapari crosses to artificial challenge with Haemonchus contortus.

Goat farming plays an important role in the Sri Lankan rural economy. Sri Lankan indigenous (SLI) goats and their crossbreds are reared mainly under extensive management and indiscriminately exposed to pathogens and parasites. This study was designed to evaluate resistance to haemonchosis in SLI goats and their Jamnapari crossbreds (JCB) in the dry zone of Sri Lanka. Twenty SLI and 20 JCB 4-month-old male goats were artificially challenged with 5000 H. contortus L3 larvae. Faecal egg counts (FEC), body weights, FAffa MAlan CHArt (FAMACHA®) scores, packed cell volumes (PCV), red blood cell counts, total and differential white blood cell counts, blood haemoglobin contents, serum total protein and albumin contents, and serum pepsinogen and antibody levels were determined at 0, 21, 28, 35 and 42days after challenge. Effects of measurement time were significant for all variables (P<0.05). Breed effects approached significance (P=0.06) and measurement time×breed interaction was significant (P<0.05) for FEC. Peak FEC occurred at day 35 in both goat types, and JCB goats had higher FEC than SLI goats at days 28 (P<0.001), 35 (P<0.10), and 42 (P<0.10). Means for FEC at day 35 were 1783±446 eggs per gram of feces (epg) for SLI kids and 3329±850 epg for JCB kids. Haematological parameters, serum chemistry, and FAMACHA scores suggested that SLI goats were recovering from parasitic infection by day 42, whereas JCB goats had increasing severity of anaemia. Means for PCV in SLI goats decreased from 26.8±0.7% at day 0 to 19.7±0.9% at day 35 and thereafter increased to 20.2±0.9% at day 42. Means for PCV in JCB goats declined from 25.9±0.6% at day 0 to 17.2±0.9% at day 42. Eosinophilia was observed in both genotypes. The JCB goats were heavier than SLI goats and had higher antibody titres, reflecting higher levels of parasitism. Both goat types significantly increased in body weight during the experiment and therefore tolerated parasite infection without severe production losses. We concluded that SLI goats were more resistant to haemonchosis than JCB goats, but that JCB goats were somewhat resilient to parasitic infection. Substantial variability in measurements associated with parasite infection in both breeds indicated potential to improve parasite resistance. Phenotypic information should be coupled with genomic information to identify appropriate breeding goals for future selection programs.

The endoparasitism challenge in developing countries as goat raising develops from smallholder to commercial production systems: A study from Laos.

Progressing economic development in Southeast Asia has increased regional demand for goat meat, leading to expanding production by smallholders and recently, development of commercial farms. In Laos, an emerging export market for goats into Vietnam has led to increased goat numbers, with potential increases in risk of disease, particularly endoparasitism. A cross-sectional survey investigated the prevalence of gastrointestinal parasites in indigenous Kambing-Katjang goats on smallholder farms (n = 389) in 8 villages where no anthelmintic treatments were in use, providing comparisons with a case study of imported Boer crossbred goats (n = 45) on a commercial farm where intensive anthelmintic treatments were required to manage mortalities attributable to Haemonchosis. Clinical examinations, collection of faecal samples, and pathological examination on the commercial farm, accompanied collection of information on animal gender, age and body weight, with data analyses performed in Genstat. Faecal samples contained eggs of multiple endoparasitic species, with Strongyles spp. and coccidian oocysts of Eimeria spp. most prevalent. Significant associations between the presence of endoparasites and the farm type (smallholder versus commercial; p < 0.008 and 0.001) were observed, with the odds ratios of the commercial farm having Stronglyes spp. and Eimeria spp. of 1.3 (CI = 0.6-2.9) and 4.8 (CI = 2.5-9.1). Mortalities from endoparasitism were only recorded at the commercial farm, with the loss of 24 goats in the final 3 months of the dry season (Feb-April). This study identified a moderate prevalence of multiple endoparasitic species in smallholder goat farms that appeared well-tolerated, whereas in the developing commercial system, endoparasites posed significant risks to enterprise viability, even with use of anthelmintics. Further studies on endoparasite control are required if commercial tropical goat meat production is to prove sustainable and assist in addressing regional food security, plus provide a pathway to improve the livelihoods of Lao goat smallholders seeking to expand and intensify their enterprises.