Gastrointestinal Nematode Parasites Research Articles

A comparison of two different anthelmintic treatment regimens against natural gastrointestinal nematode infections on two Lithuanian sheep farms

BackgroundAccording to targeted treatment (TT), the whole flock is dewormed based on knowledge of the risk, or parameters that quantify the mean level of infection, whereas according to targeted selective treatment (TST), only individual animals within the grazing group are treated, based on parasitological, production and/or morbidity parameters. The aim of this study was to compare two different treatment protocols on sheep farms in Lithuania. The study was conducted from 15 April to 31 October 2014 on three sheep farms. On the TT (the whole flock) and T(S)T (with FECs ≥ 300, respectively) farms all adult animals were treated orally with fenbendazole irrespective of EPG counts before the grazing season. The second treatment was applied with injectable ivermectin on both farms. However, on the TT farm all sheep were also treated on 2nd August regardless of their EPG counts, while on the T(S)T farm only those animals with an EPG ≥ 300 were treated on 1 July using a threshold of ≥ 300 EPG. No treatments were administered on the control farm (n = 1) during the study.ResultsSpring treatment of ewes significantly reduced nematode faecal egg counts (FEC) both on the TT and T(S)T farms, with the benefit of lowering pasture contamination with infective L3 stage larvae at the start of grazing season, while it remained significantly higher on the control farm. The positive effect of the spring treatment of ewes was reflected by increased body weight gains (BWG) in lambs in the first half of the grazing season. Following the second treatment, the weight gains in lambs on the T(S)T farm were higher compared to lambs on the TT farm, while BWG in the control lambs started to decrease. The difference was also substantiated by the body condition scores (BCS) and dag scores (DS) of lambs, which were highest on the T(S)T farm compared with those on the control and TT farms.ConclusionsThe results of this study show that both treatment strategies were useful in reducing clinical effects (BCS and DS) of gastrointestinal nematode parasitism and increasing the performance in lambs. Furthermore, on the T(S)T farm some of animals were left in refugia, helping to slow down the development of anthelmintic resistance (AR) in future.

Prevalence of gastrointestinal nematode resistance to avermectin anthelmintics on beef cattle operations in Georgia

Anthelmintic resistance is a worldwide problem in all livestock systems, with most reports of resistance in cattle parasites being to the macrocyclic lactone (ML) drug class. Several prevalence studies performed internationally demonstrate that anthelmintic resistance in cattle parasites is a growing problem, however, no similar studies have been performed in the US. The primary objective of this study was to gain data on the prevalence of ML resistance in gastrointestinal nematode (GIN) parasites on beef cattle farms in Georgia. We also wanted to test the efficacy of combination anthelmintic therapy in these same herds, and use these data as a basis for educational outreach programs for beef producers in Georgia.

Assessment of gastrointestinal nematode parasitism in dairy calves housed in calf hutches

Gastrointestinal nematodes (GIN) are an important cause of morbidity and production losses in cattle. Clinical infection with GIN can cause diarrhea and hypoalbuminemia, but subclinical infections are more prevalent, harder to recognize, and a greater threat to productivity. Emphasis in the dairy industry has been placed on management strategies to mitigate disease and productive losses caused by GIN infections in grazing heifers and adult cattle, but hutch calves have largely been left out of this discussion. Milk-fed dairy calves housed in hutches are presumed not to acquire GIN infection because transmission of GIN is thought to require exposure to a pasture environment and subsequent ingestion of contaminated forage. However, a recent assessment of fecal egg counts (FEC) in hutch calves for another research project revealed calves raised in hutches with unexpectedly high FEC. The objective of this study was to estimate the prevalence and magnitude of GIN in hutch calves on two calf ranches and to evaluate factors associated with the probability for calves to be parasitized.

Infections by human gastrointestinal helminths are associated with changes in faecal microbiota diversity and composition.

Investigations of the impact that patent infections by soil-transmitted gastrointestinal nematode parasites exert on the composition of the host gut commensal flora are attracting growing interest by the scientific community. However, information collected to date varies across experiments, and further studies are needed to identify consistent relationships between parasites and commensal microbial species. Here, we explore the qualitative and quantitative differences between the microbial community profiles of cohorts of human volunteers from Sri Lanka with patent infection by one or more parasitic nematode species (H+), as well as that of uninfected subjects (H-) and of volunteers who had been subjected to regular prophylactic anthelmintic treatment (Ht). High-throughput sequencing of the bacterial 16S rRNA gene, followed by bioinformatics and biostatistical analyses of sequence data revealed no significant differences in alpha diversity (Shannon) and richness between groups (P = 0.65, P = 0.13 respectively); however, beta diversity was significantly increased in H+ and Ht when individually compared to H-volunteers (P = 0.04). Among others, bacteria of the families Verrucomicrobiaceae and Enterobacteriaceae showed a trend towards increased abundance in H+, whereas the Leuconostocaceae and Bacteroidaceae showed a relative increase in H- and Ht respectively. Our findings add valuable knowledge to the vast, and yet little explored, research field of parasite—microbiota interactions and will provide a basis for the elucidation of the role such interactions play in pathogenic and immune-modulatory properties of parasitic nematodes in both human and animal hosts.

Nematophagous fungi combinations reduce free-living stages of sheep gastrointestinal nematodes in the field

Gastrointestinal nematodes (GIN) can reduce or limit sheep production. Currently there is a clear deficiency in the action of drugs for the control of these parasites. Nematophagous fungi are natural enemies of GIN. Fungal combinations have potential for reducing GIN populations. The aim of this study was to evaluate the efficiency combinations of nematophagous fungi in sodium alginate matrix pellets for the biological control agents of gastrointestinal sheep nematode parasites in the field. The nematophagous fungi (0.2mg of fungus per kg of body weight), Arthrobotrys conoides, A. robusta, Duddingtonia flagrans, and Monacrosporium thaumasium were used. The treated groups were administered mycelium combinations in the following combinations: group 1 (D. flagrans+A. robusta); group 2 (M. thaumasium+A. conoides). The control group did not receive any fungal pellets. We used three groups with eight Santa Inês sheep each. Each animal was treated with approximately 1g of pellet per 10kg of live weight. During the experimental period, we evaluated: number of eggs per gram of feces (EPG), infective larvae (L3) per kg of dry matter, larvae recovered from coprocultures, packed cell volume, total plasma protein concentration of sheep, and environmental conditions. Group 2 EPG (M. thaumasium+A. conoides) differed from the control group in September and October. The number of L3/kg of dry matter recovered from animals of groups 1 and 2 at distances of 0-20 and 20-40cm from the fecal pats was lower than the control group. The packed cell volume and total plasma proteins of treated animals were similar to those of the control group. The combination of treatment groups (D. flagrans+A. robusta and M. thaumasium+A. conoides) reduced the number of L3/kg of pasture. Therefore, treatment of nematophagous fungal combinations have the potential to manage free-living stages of GIN in sheep.

The use of nemabiome metabarcoding to explore gastro-intestinal nematode species diversity and anthelmintic treatment effectiveness in beef calves

Next-generation deep amplicon sequencing, or metabarcoding, has revolutionized the study of microbial communities in humans, animals and the environment. However, such approaches have yet to be applied to parasitic helminth communities. We recently described the first example of such a method – nemabiome sequencing – based on deep-amplicon sequencing of internal transcribed spacer 2 (ITS-2) rDNA, and validated its ability to quantitatively assess the species composition of cattle gastro-intestinal nematode (GIN) communities. Here, we present the first application of this approach to explore GIN species diversity and the impact of anthelmintic drug treatments. First, we investigated GIN species diversity in cow-calf beef cattle herds in several different regions, using coproculture derived L3s. A screen of 50 Canadian beef herds revealed parasite species diversity to be low overall. The majority of parasite communities were comprised of just two species; Ostertagia ostertagi and Cooperia oncophora. Cooperia punctata was present at much lower levels overall, but nevertheless comprised a substantive part of the parasite community of several herds in eastern Canada. In contrast, nemabiome sequencing revealed higher GIN species diversity in beef calves sampled from central/south-eastern USA and Sao Paulo State, Brazil. In these regions C. punctata predominated in most herds with Haemonchus placei predominating in a few cases. Ostertagia ostertagi and C. oncophora were relatively minor species in these regions in contrast to the Canadian herds. We also examined the impact of routine macrocyclic lactone pour-on treatments on GIN communities in the Canadian beef herds. Low treatment effectiveness was observed in many cases, and nemabiome sequencing revealed an overall increase in the proportion of Cooperia spp. relative to O. ostertagi post-treatment. This work demonstrates the power of nemabiome metabarcoding to provide a detailed picture of GIN parasite community structure in large sample sets and illustrates its potential use in research, diagnostics and surveillance.

Validation of DESS as a DNA Preservation Method for the Detection of Strongyloides spp. in Canine Feces.

Strongyloides stercoralis is a gastrointestinal parasitic nematode with a life cycle that includes free-living and parasitic forms. For both clinical (diagnostic) and environmental evaluation, it is important that we can detect Strongyloides spp. in both human and non-human fecal samples. Real-time PCR is the most feasible method for detecting the parasite in both clinical and environmental samples that have been preserved. However, one of the biggest challenges with PCR detection is DNA degradation during the postage time from rural and remote areas to the laboratory. This study included a laboratory assessment and field validation of DESS (dimethyl sulfoxide, disodium EDTA, and saturated NaCl) preservation of Strongyloides spp. DNA in fecal samples. The laboratory study investigated the capacity of 1:1 and 1:3 sample to DESS ratios to preserve Strongyloides ratti in spike canine feces. It was found that both ratios of DESS significantly prevented DNA degradation compared to the untreated sample. This method was then validated by applying it to the field-collected canine feces and detecting Strongyloides DNA using PCR. A total of 37 canine feces samples were collected and preserved in the 1:3 ratio (sample: DESS) and of these, 17 were positive for Strongyloides spp. The study shows that both 1:1 and 1:3 sample to DESS ratios were able to preserve the Strongyloides spp. DNA in canine feces samples stored at room temperature for up to 56 days. This DESS preservation method presents the most applicable and feasible method for the Strongyloides DNA preservation in field-collected feces.

Excretory/secretory products from the gastrointestinal nematode Trichuris muris

To better control gastrointestinal nematode infections in humans and animals, it is important to understand the strategies used by these parasites to modulate the host immune system. In this regard, molecules released by parasites have been attributed crucially important roles in host-parasite negotiations. We characterized the excretory/secretory (E/S) microRNA (miRNA) and protein profiles from the mouse gastrointestinal nematode parasite Trichuris muris. Released miRNAs were subjected to miRNA sequencing and E/S proteins were analysed by mass spectrometry. Fourteen miRNAs were identified in T. muris exosome-like vesicles, as well as 73 proteins of nematode origin, 11 of which were unique to this study. Comparison with published nematode protein secretomes revealed high conservation at the functional level.

An observational study of naturally occurring gastrointestinal nematode infections in a seasonal grazing cow-calf herd in southern Ontario

Little work has been done to determine the prevalence of gastrointestinal nematodes (GIN) in Ontario cow–calf herds. A prospective single cohort study was conducted during the grazing seasons of 2014 and 2015. Twenty-four crossbred cows were randomly assigned to one of six rotationally grazed fields each year, blocked by calving date and parity (n = 48). Feces were collected and weight and body condition score (cows) recorded at approximately 28 d intervals. Fecal egg counts (FEC) were performed using the Wisconsin method. No clinical signs of GIN parasitism were observed. Cow FEC stayed relatively low throughout both pasture seasons [mean 8 ± 20.02 eggs per gram (epg) of feces, n = 301]. Most calf FEC were also low throughout both seasons (mean 42 ± 86.20 epg, n = 268). The sample time [a proxy for days on pasture (DOP)] had a significant effect on cow epg (P < 0.001) and calf epg (P < 0.001). Cow and calf FEC peaked at the fourth sample, after 55–72 DOP; 4 epg (95% CI 2.57, 6.32) and 24 epg (95% CI 15.8...

The impact of a mixture of medicinal herbs on ruminal fermentation, parasitological status and hematological parameters of the lambs experimentally infected with Haemonchus contortus

The aim of this study was to determine the effect of dietary supplementation with a mixture of selected medicinal herbs (Herbmix) on hematological and parasitological parameters and on the inflammatory response of lambs infected experimentally with the gastrointestinal parasitic nematode Haemonchus contortus. Herbmix contained selected medicinal herbs common in central Europe (8.55% each of Althaea officinalis, Petasites hybridus, Inula helenium, Malva sylvestris, Chamomilla recutita, Plantago lanceolata, Rosmarinus officinalis, Solidago virgaurea, Fumaria officinalis, Hyssopus officinalis and Melissa officinalis, 5% Foeniculum vulgare and 1% Artemisia absinthium). Herbmix (100g dry matter (DM)/d) was added to the basal diets of meadow hay (600g DM/d) and a commercial concentrate (350g DM/d) per animal. Twenty-four female lambs were divided into four groups: infected animals (Inf), infected animals supplemented with Herbmix (Inf+Herb), uninfected control animals (C) and uninfected animals supplemented with Herbmix (C+Herb). Inf and Inf+Herb lambs were infected orally with approximately 5000 L3 larvae of a strain of H. contortus susceptible to anthelmintics (MHco1). Herbmix supplementation for Inf+Herb and C+Herb began on day 0 (D0). Feces were collected and eggs per gram (EPG) of feces were quantified on D0, D20, D32, D50 and D60. Variables differed after 24h of ruminal incubation of the individual medicinal herbs (P<0.001), but the herbs had no negative effect on the fermentation patterns. The mean EPG counts were significantly lower by 45% between D32 and D50 (P<0.05) and by 63% between D32 and D60 (P<0.01) for the infected lambs receiving Herbmix (Inf+Herb). These EPG reductions were only 10 and 30% in infected group (Inf, P>0.05). Mean cumulative gain in live weight was higher in Inf+Herb as compared to Inf by D32 (P<0.01) and D50 (P<0.001). The evaluation of red blood cells identified clinical signs of haemonchosis, such as anemia, in Inf and Inf+Herb. Total antioxidant capacity (P<0.008) and activity of glutathione peroxidase (P<0.005) in serum at D50 were lower in Inf and Inf+Herb than C and C+Herb. The concentration of serum calprotectin differed significantly (P<0.001) in Inf vs. Inf+Herb. The Zn and Fe serum concentrations differed significantly (P<0.05 and P<0.001, respectively) in Inf vs. Inf+Herb, Inf vs. C and Inf vs. C+Herb by D32. The mixture of the medicinal herbs thus contributed to slowing the dynamics of infection and improving the production indicators of the animals.

Prevalence of Gastrointestinal Nematoda in Cattle In Pintu Rime Gayo Highland of Bener Meriah Regency

This study was carried out to assess the prevalence of gastrointestinal nematode in cattle in the Pintu Rime Gayo, a highland sub district of Bener Meriah Regency, Aceh according to age and sex. Stool samples were collected from 150 cattle aged 0-6, 7-12 and 12 months old. Examination was performed by using a centrifuge. Samples tested positive when found gastrointestinal nematode parasite eggs. The data obtained were analyzed with Chi-Square. The results showed that the prevalence of gastrointestinal nematode in cattle aged 0-7 months (32%) was significantly higher (p0.05) than that in cattle aged 7-12 months (22%) and 12 months (12%). The parasite was markedly more prevalent (p0.05) in female cattle (23.9%) than that in male cattle (15.2%). In conclusion, susceptibility of cattle in the Pintu Rime Gayo highland to gastrointestinal nematode infection was influenced by both age and sex.

Uncertain links in host-parasite networks: lessons for parasite transmission in a multi-host system.

For many parasites, the full set of hosts that are susceptible to infection is not known, and this could lead to a bias in estimates of transmission. We used counts of individual adult parasites from historical parasitology studies in southern Africa to map a bipartite network of the nematode parasites of herbivore hosts that occur in Botswana. Bipartite networks are used in community ecology to represent interactions across trophic levels. We used a Bayesian hierarchical model to predict the full set of host–parasite interactions from existing data on parasitic gastrointestinal nematodes of wild and domestic ungulates given assumptions about the distribution of parasite counts within hosts, while accounting for the relative uncertainty of less sampled species. We used network metrics to assess the difference between the observed and predicted networks, and to explore the connections between hosts via their shared parasites using a host–host unipartite network projected from the bipartite network. The model predicts a large number of missing links and identifies red hartebeest, giraffe and steenbok as the hosts that have the most uncertainty in parasite diversity. Further, the unipartite network reveals clusters of herbivores that have a high degree of parasite sharing, and these clusters correspond closely with phylogenetic distance rather than with the wild/domestic boundary. These results provide a basis for predicting the risk of cross-species transmission of nematode parasites in areas where livestock and wildlife share grazing land.This article is part of the themed issue ‘Opening the black box: re-examining the ecology and evolution of parasite transmission’.

Grassland management and helminth control on livestock farms

Most species of gastrointestinal and pulmonary parasitic nematodes of cattle and sheep are host specific and farmers with mixed livestock farms can take advantage of this aspect of parasite biology to mitigate and control pasture-associated parasite infections through mixed or co-grazing. However, some common parasites, such as liver and rumen fluke, are generalists and can parasitise a wide range of mammalian hosts, nevertheless, differences in host responses have the potential to be used to manage high-risk fields, without compromising health or performance. Current research is exploring the possible role of bioactive plants in the control of parasites.

Immunological Responses to Pneumococcal Conjugate Vaccine and Intestinal Nematodes Infestation in Children

Pneumonia is among the leading killer diseases of children under five years in Kenya. The most common bacteriological cause of severe and fatal pneumonia is Streptococcus pneumonia (S. pneumonia). S. pneumoniae is usually carried in the nasopharynx of healthy people, but occasionally leads to invasive pneumococcal diseases (IPDs), such as meningitis, pneumonia, otitis, sinusitis and bacteremia. Annually, World Health Organization (WHO) estimates the occurrence of one and a half million of deaths in children under five years, mainly in poor countries. In Kenya, A 10-valent Pneumococcal Conjugate Vaccine (PCV10) introduction into routine immunization schedule has resulted in reduction of the incidence of Invasive Pneumococcal diseases (IPD). However, there is a need to systematically evaluate the confounding factors that limit vaccine efficacy. A common although often overlooked confounding factor in the PCV10 vaccination efficacy is the presence of gastrointestinal nematode parasites in humans, particularly in children living in slums. Here the intestinal nematodes are prevalent and their effects result in an immuno-compromised state. We review the possibility of concurrent intestinal nematode infestation altering PCV10-induced responses in children and the need to devise efficacious treatment strategies.

Prevalence and Risk Factors of Gastrointestinal Nematodes Infections in Small Ruminants in Tullo District, Western Harerghe, Ethiopia

A cross-sectional study was carried out in sheep and goats kept under extensive management system in Tullo district, Western Harerghe zone of Oromia Regional State, Ethiopia, during the period from November, 2013 to April, 2014. The main objectives of the study were to estimate the prevalence of nematode infection in small ruminants and to assess associated risk factors with its occurrence. A total of 384 fecal samples were collected from 168 sheep and 216 goats. The samples were examined using floatation technique and eggs per gram of faeces were determined. The overall prevalence for the nematode infection was 50.8% (195/384). Different nematode eggs including Strongyle (177, 46.1%), Strongyloides (35, 9.1%) and Trichuris eggs (31, 8.1%) were identified. The mean eggs per gram count showed that, 100 (56.5%) were heavily infected, 61(34.5%) were moderately infected and the remaining were lightly infected. The coproculture examination from the positive samples for strongyle eggs revealed the presence of Trichostrongylus species (sp), Haemonchus sp., Oesophagostomum sp., Cooperia sp., and Bunostomum sp. Gastrointestinal nematode parasitism is more prevalent (AOR=2.23) in sheep as compared to goats. It was also higher in animals with poor (AOR=4.54) and medium body conditions (AOR=2.02) as compared to animals with good body conditions. However, there was no statistically significant association between the occurrence of the infection and age, sex and origin of the animals’. In conclusion, gastrointestinal nematode parasites were highly prevalent in the study area and this could hamper health and productivity of the small ruminants. Thus, strategic control of nematode parasites should be planned and implemented to reduce the economic losses and welfare problems of the animals.

Gastrointestinal Nematode Parasites of Small Ruminants and Anthelmintics Efficacy Test in Sheep of Haramaya District, Eastern Ethiopia

The combination of cross-section and controlled field trail were carried out from December 2015 to June 2016 at Haramaya District, Eastern Hararhge, Ethiopia to evaluate the prevalence ofgastrointestinal nematodes and anthelmintic efficacy test in naturally infected small ruminants using faecal egg count reduction (FECR) test. From a total of 372 faecal samples examined using fecal flotation technique about 57% (212/372) samples were positive to gastrointestinal nematodes. Coprological investigation revealed that sheep and goats in district were infested with varieties of nematode parasites. The strongyles species were highly prevalent nematode parasites identified at about 22.3% (83/372) followed by trichuris 9.1% (34/372) and strongyloides 5.6% (21/372); whereas mixed infections of strongyles and strongyloides were recovered at lowest rate which accounted for about 5.1% (19/372). From considered risk factors age and kebele showed significant association (p&lt;0.05) with prevalence of nematodes parasites. The study revealed that 53.29% (97/182) of goats and 60.53% (115/190) sheep were found positive, while 58% (115/198) in female and 55.74% (97/174) in male and showed no significant difference (p&gt;0.05) between these factors. Mc Master egg counting in sheep harbored nematode parasites showed relatively similar percentage with no significant difference; but more of examined animals were classified in the range of moderate to heavy infections. The faecal egg count reduction test against albendazole, Tetraclozash and ivermectin indicated that 97.59%, 98.79% and 99.56% respectively which indicated an overall of very good state of efficacy against gastrointestinal nematodes of sheep. Therefore this study revealed that small ruminants of the study area harbored considerable level of gastrointestinal nematodes parasites which need further studies on species identification, larval ecology and strategic deworming with proper practice of available anthelmintics in small ruminants of the study area.

Factors affecting fecal egg counts in periparturient Katahdin ewes and their lambs.

Selection for low fecal egg counts (FEC) can be used to genetically enhance resistance to gastrointestinal nematode parasites in growing lambs, thereby reducing the frequency of use of anthelmintics, facilitating marketing of organic lamb, and reducing the risk of development of anthelmintic resistance by the parasite. Recording of FEC in lambs has, therefore, been incorporated into several national sheep genetic evaluation programs. Ewes in late gestation and early lactation are also vulnerable to parasite infection and commonly experience a periparturient rise in FEC. This study was designed to assess factors associated with the periparturient rise in FEC in Katahdin ewes and associated changes in FEC in their lambs. Data came from 1,487 lambings by 931 Katahdin ewes from 11 farms in the Eastern United States. Fecal egg counts were measured in ewes at approximately 0, 30, and 60 d postpartum and in their lambs at approximately 60, 90, and 120 d of age. Approximately 1,400 lambs were evaluated at each measurement age. Data were analyzed separately for ewes and lambs and also initially analyzed separately for each measurement time. Repeated-measures analyses were then used to evaluate responses across measurement times. In ewes, FEC peaked at approximately 28 d postpartum, and we concluded that informative periparturient FEC could be obtained from 1 wk before until approximately 5 wk after lambing. Yearling ewes had higher FEC than adult ewes ( < 0.01), and ewes that nursed twin or triplet lambs had higher FEC than ewes that nursed single lambs ( < 0.01). In lambs, FEC increased through approximately 120 d of age. Lambs from yearling ewes and lambs nursed in larger litters were, like their dams, at greater risk of parasitism ( < 0.05). Ewes and lambs in these groups would benefit from enhanced monitoring of parasite loads at lambing and in early lactation. Correlations () between FEC in lambs at 90 d of age and FEC in ewes at 0, 30, and 60 d postpartum of 0.05 to 0.09 ( ≤ 0.05) support the presence of a genetic relationship between these 2 indicators of parasite resistance.

Goat is not a scapegoat in escalating anthelmintic resistance in Small Ruminants

Sheep and goats share the same species of gastrointestinal nematode parasites. The browsing animals (goats) suffer from parasitic gastroenteritis with comparatively lesser burden of parasitic nematodes than in sheep. Traditionally the dose rates of anthelmintics used in goats to control gastrointestinal nematodes are same as in sheep. Pharmacokinetics of anthelmintics in general, benzimidazoles and closantel in particular, reveal that goats remove anthelmintics from their body faster than sheep resulting in the reduced bioavailability of anthelmintics. Administration of anthelmintics in goats at dose rate recommended for sheep results in lower efficacy that in turn, results in the heterozygote resistant parasites being selected. The dosing of goats with the sheep dose of anthelmintics is similar in consequence to under-dosing with the effect of allowing the heterozygote resistant worms to survive. Goats are thus singularly blamed with the claim that resistance develops first in goats and then spread into the sheep flock. The ways of tackling the problem of anthelmintic resistance in goats are discussed.

Predation rate of nematophagous fungi after passing through the gastrointestinal tract of goats

Nematophagous fungi are natural enemies of gastrointestinal helminth parasites. Fungi Arthrobotrys robusta (I31), Arthrobotrys conoides (I40), Duddingtonia flagrans (AC001), and Monacrosporium thaumasium (NF34) were combined: AC001+I31 and NF34+I40 and tested for the biological control of parasitic gastrointestinal nematode of goats in two trials. In trial A, the objective was to evaluate the predation capacity of the AC001+I31 and NF34+I40 fungi combinations in vitro. In trial B, the viability of the nematophagous fungi combination (conidia and chlamydospores/kg live weight) was evaluated after passage through the gastrointestinal tract of goats. In trial A, the combination of the AC001+I31 and I40+NF34 isolates reduced the number of L3 larvae of gastrointestinal nematodes (p<0.01) by 93 and 98% respectively. In trial B, the isolates AC001+I31 and NF34+I40 combination passed through the gastrointestinal tract of goats and reduced the number of L3 larvae in the gastrointestinal nematodes in vitro. The number of larvae recovered was 53 and 68% lower in the group treated with the isolates AC001+I31 after 12 (p<0.01) and 48 (p<0.05)h of inoculation respectively. The combination of NF34+I40 reduced the proportion of larvae by 56, 61, and 48%, after 24, 48, and 72h respectively. The combinations of the fungi AC001+I31 and I40+NF34 showed high predatory activity in vitro and passed through the gastrointestinal tract of goats without predation viability losses.

Evaluation of parasite resistance to commonly used commercial anthelmintics in meat goats on humid subtropical pasture

Anthelmintic-resistant gastrointestinal nematode parasites are a threat to small ruminant industry sustainability. Meat goat does were administered one of four anthelmintics orally (ivermectin (n=18), moxidectin (n=18), levamisole hydrochloride (n=17), or albendazole (n=19)) or water (n=18). Fecal samples were collected pretreatment and 12days post-treatment. Fecal egg counts (FEC) were determined by the modified McMaster technique. The FEC reduction percentages (FECR%) were calculated using three equations. Log transformed FEC means were analyzed by treatment, sire breed of doe, and doe age. Sire breed affected (P<0.05) pretreatment FEC, but not post-treatment FEC (P=0.12). Pretreatment FEC did not differ (P=0.21) by treatment group. Posttreatment FEC varied (P<0.05) by treatment. Anthelmintic resistance determinations were based on FECR% falling below 90% or 80%, dependent on equation applied. Resistance was detected to all four anthelmintics using each equation. These results suggest the need for alternative methods of internal parasite control in goats.