Biological control of goat gastrointestinal helminthiasis by Duddingtonia flagrans in a semi-arid region of the northeastern Brazil

Assessing the efficacy of the ovicidal fungus Mucor circinelloides in reducing coccidia parasitism in peacocks

The biological control of gastrointestinal (GI) parasites using predatory fungi has been recently proposed as an accurate and sustainable approach in birds. The current study aimed to assess for the first time the efficacy of using the native ovicidal fungus Mucor circinelloides (FMV-FR1) in reducing coccidia parasitism in peacocks. For this purpose, an in vivo trial was designed in the resident peacock collection (n = 58 birds) of the São Jorge Castle, at Lisbon, Portugal. These animals presented an initial severe infection by coccidia of the genus Eimeria (20106 ± 8034 oocysts per gram of feces, OPG), and thus received commercial feed enriched with a M. circinelloides suspension (1.01 × 108 spores/kg feed), thrice-weekly. Fresh feces were collected every 15 days to calculate the coccidia shedding, using the Mini-FLOTAC technique. The same bird flock served simultaneously as control (t0 days) and test groups (t15-t90 days). The average Eimeria sp. shedding in peacocks decreased up to 92% following fungal administrations, with significant reduction efficacies of 78% (p = 0.004) and 92% (p = 0.012) after 45 and 60 days, respectively. Results from this study suggest that the administration of M. circinelloides spores to birds is an accurate solution to reduce their coccidia parasitism.

Biotic interactions in soil and dung shape parasite transmission in temperate ruminant systems: An integrative framework

Gastrointestinal helminth parasites undergo part of their life cycle outside their host, such that developmental stages interact with the soil and dung fauna. These interactions are capable of affecting parasite transmission on pastures yet are generally ignored in current models, empirical studies and practical management. Dominant methods of parasite control, which rely on anthelmintic medications for livestock, are becoming increasingly ineffective due to the emergence of drug-resistant parasite populations. Furthermore, consumer and regulatory pressure on decreased chemical use in agriculture and the consequential disruption of biological processes in the dung through nontarget effects exacerbates issues with anthelmintic reliance. This presents a need for the application and enhancement of nature-based solutions and biocontrol methods. However, successfully harnessing these options relies on advanced understanding of the ecological system and interacting effects among biotic factors and with immature parasite stages. Here, we develop a framework linking three key groups of dung and soil fauna-fungi, earthworms, and dung beetles-with each other and developmental stages of helminths parasitic in farmed cattle, sheep, and goats in temperate grazing systems. We populate this framework from existing published studies and highlight the interplay between faunal groups and documented ecological outcomes. Of 1756 papers addressing abiotic drivers of populations of these organisms and helminth parasites, only 112 considered interactions between taxa and 36 presented data on interactions between more than two taxonomic groups. Results suggest that fungi reduce parasite abundance and earthworms may enhance fungal communities, while competition between dung taxa may reduce their individual effect on parasite transmission. Dung beetles were found to impact fungal populations and parasite transmission variably, possibly tied to the prevailing climate within a specific ecological context. By exploring combinations of biotic factors, we consider how interactions between species may be fundamental to the ecological consequences of biocontrol strategies and nontarget impacts of anthelmintics on dung and soil fauna and how pasture management alterations to promote invertebrates might help limit parasite transmission. With further development and parameterization the framework could be applied quantitatively to guide, prioritize, and interpret hypothesis-driven experiments and integrate biotic factors into established models of parasite transmission dynamics.

Evaluation of the supply of Duddingtonia flagrans for the control of gastrointestinal parasites in sheep

Parasitic resistance imposes alternative control methods, like nematophagous fungi. In this study, two experiments were conducted supplying Duddingtonia flagrans aiming to evaluate the biological control of parasites in sheep. In the first, 24 sheep naturally infected by gastrointestinal nematodes were allocated, in randomized blocks, following the treatments: control or treated group, 0.5g/animal product containing D. flagrans, chlamydospores. Weight, body score, Famacha©, egg count per gram of feces (EPG), and larval percentage were evaluated. In the second experiment, D. flagrans (0.25 and 0.5g product) was infested with manure, plus or not protein concentrate, in a completely randomized design. In both experiments the dose was intentionally lower than recommended. Recovery and larval identification were performed. The SAS analyzed the variables by the MIXED procedure, repeated measures in time. Weight, body score, hematocrit, and Famacha© did not show differences between treatments (p>0.05); however, EPG (p<0.001) and the percentage of larvae identified in coproculture were different. In the second experiment, the inclusion of the fungus did not influence the recovery of larvae (p>0.05). In both experiments, colonization and advancement of the fungus were visualized. Under the experimental conditions, the fungus D. flagrans was not effective in the biological control of parasitic infection in sheep.

Efficiency of Experimental Formulation Containing Duddingtonia flagrans and Pochonia chlamydosporia against Moniezia expansa Eggs

This study aimed to evaluate the effectiveness of the experimental formulation containing chlamydospores of Duddingtonia flagrans and Pochonia chlamydosporia fungi, against Moniezia expansa. Two experiments were carried out. The first experiment evaluated the in vitro efficacy using 1 g of the experimental formulation (V1) added to 100 M. expansa eggs and the control (V2) (without the fungal formulation). Intact eggs or eggs with alterations were counted in order to evaluate their effectiveness. The second experiment evaluated the action of the fungal formulation on M. expansa eggs after passing through the gastrointestinal tract of goats. Three groups were identified as B1, B2, and B3, which received 1.0, 1.5 g of experimental fungal formulation, and placebo, respectively. In experiment 1, all the eggs in V1 were subjected to the predatory action of fungi, while in V2, the eggs remained intact. In experiment 2, the reduction of eggs in groups B1 and B2 were 49% and 57% 24 h after ingestion, 60% and 63% 48 h after, and 48% and 58% 72 h after. The predatory capacity against M. expansa eggs shown in the tests demonstrated that experimental fungal formulation has the potential to be used on integrated helminth control programs.

Establishment of Arthrobotrys flagrans as biocontrol agent against the root pathogenic nematode Xiphinema index

Plant-parasitic nematodes cause devastating agricultural damage worldwide. Only a few synthetic nematicides can be used and their application is limited in fields. Therefore, there is a need for sustainable and environment-friendly alternatives. Nematode-trapping fungi (NTF) are natural predators of nematodes. They capture and digest them with their hyphae and are starting to being used as bio-control agents. In this study, we applied the NTF Arthrobotrys flagrans (Duddingtonia flagrans) against the wine pathogenic nematode Xiphinema index. A. flagrans reduced the number of X. index juveniles in pot cultures of Ficus carica, an alternative host plant for X. index, significantly. Sodium-alginate pellets with A. flagrans spores were produced for vineyard soil inoculation under laboratory conditions. The NTF A. conoides, A. musiformis and A. superba were enriched from several soil samples, showing their natural presence. Trap formation is an energy-consuming process and depends upon various biotic and abiotic stimuli. Here, we show that bacteria of the genus Delftia, Bacillus, Pseudomonas, Enterobacter and Serratia induced trap formation in NTF like A. conoides and A. oligospora but not in A. flagrans in the absence of nematodes. The application of NTF along with such bacteria could be a combinatorial way of efficient biocontrol in nematode-infested soil.

Drechslerelladaliensis and D.xiaguanensis (Orbiliales, Orbiliaceae), two new nematode-trapping fungi from Yunnan, China

Background

Nematode-trapping fungi are a highly specialised group in fungi and are essential regulators of natural nematode populations. At present, more than 130 species have been discovered in Zygomycota (Zoopagaceae), Basidiomycota (Nematoctonus), and Ascomycota (Orbiliaceae). Amongst them, nematode-trapping fungi in Orbiliaceae have become the research focus of carnivorous fungi due to their abundant species. During the investigation of carnivorous fungi in Yunnan, China, four fungal strains isolated from burned forest soil were identified as two new nematode-trapping species in Drechslerella (Orbiliaceae), based on multigene phylogenetic analysis and morphological characters.

New information

Drechslerelladaliensis sp. nov. is characterised by its ellipsoid, 1-2-septate macroconidia, clavate or bottle-shaped, 0-1-septate microconidia and unbranched, simple conidiophores. D.xiaguanensis sp. nov. is characterised by fusiform or spindle-shaped, 2-4-septate conidia and unbranched, simple conidiophores. Both of them produce constricting rings to capture nematodes. The phylogenetic analysis, based on combined ITS, TEF1-α and RPB2 sequences, determined their placement in Drechslerella. D.daliensis forms a basal lineage closely nested with D.hainanensis (YMF1.03993). D.xiaguanensis forms a sister lineage with D.bembicodes (1.01429), D.aphrobrocha (YMF1.00119) and D.coelobrocha (FWY03-25-1).

Castor bean cake for the control of parasites in pasture-finished sheep

The purpose of this study was to evaluate castor bean cake as alternative input in the control of gastrointestinal parasites in sheep raised on irrigated pasture under continuous stocking. The treatments consisted of sheep supplemented with standard diet and pasture fertilized with urea; sheep supplemented with alternative diet and pasture fertilized with urea; sheep supplemented with standard diet and pasture fertilized with in natura castor bean cake; and sheep supplemented with alternative diet and pasture fertilized with in natura castor bean cake. A randomized complete block design (CBD) was used, with 16 replications (sheep), with repeated measures over time, the plots being the treatments, and the subplots the collection times. Infective nematode larvae in the pasture (L3.g DM⁻¹), number of eggs per gram of feces (EPG), globular volume (GV), and total plasma protein (TPP) were evaluated. For adult gastrointestinal parasite counts, CBD was also used with six replications. Except for FAMACHA^© grade, all variables had effect (P < 0.01) of the time factor. The average number of L3.g DM⁻¹ and EPG were 126 and 841, respectively, with no effect (P > 0.05) of the treatment factor. The values observed for GV and TPP were higher than 25.9% and 6.4 g·dL⁻¹, respectively, which were considered normal. As organic fertilizer, the fractionated application of in natura castor bean cake does not reduce the contamination of pastures by nematode larvae. The evaluated feeds improve the resilience of the sheep to infection by gastrointestinal parasites. The treatments using castor bean cake reduced the adult parasites present in the abomasum of sheep.

Efficacy of a Fungal Formulation with the Nematophagous Fungus Pochonia chlamydosporia in the Biological Control of Bovine Nematodiosis

In the control of bovine worms, biological control by nematophagous fungi stands out, especially Pochoniachlamydosporia which causes the destruction of helminth eggs. This study aims to test the effectiveness of a formulation containing the nematophagous fungus Pochonia chlamydosporia isolated for the biological control of bovine nematodiosis. Twelve cattle were divided into two groups: control group (GC) and the group that received the formulation (GT). Feces and pasture samples were collected for the research of gastrointestinal nematodes. Lung worms and trematodes were investigated. The animals were weighed monthly. The averages of temperature and rainfall were recorded. The supply of the fungus Pochonia chlamydosporia was not effective in reducing the eggs per gram of feces of gastrointestinal nematodes (EPG) of the animals, not differing statistically (p > 0.05) between the groups. The mean values of larvae recovered in the pasture did not differ significantly (p > 0.05). The genus Haemonchus sp. was the most prevalent. There was no correlation between the number of larvae with temperature and rainfall (p > 0.05). There was a statistically significant difference (p < 0.05) in the penultimate weighing of the experiment. The formulation containing Pochonia chlamydosporia was not efficient in the biological control of bovine gastrointestinal nematodes.

Control of sheep gastrointestinal nematodes on pasture in the tropical semiarid region of Brazil, using Bioverm® (Duddingtonia flagrans)

We aimed to evaluate a Brazilian commercial formulation of the fungus Duddingtonia flagrans (Bioverm®) for controlling gastrointestinal nematodes in sheep kept on native pasture in the Caatinga biome, in the semiarid region of Brazil. Twenty ewes, aged between 12 and 18 months, were divided into two groups. In the treated group, each animal received 1 g of the Bioverm® product for each 10 kg of live weight, daily, together with commercial feed, for 6 months. In the control group, the animals received feed without Bioverm®. Each group remained throughout the experiment in a 1.2-ha paddock. Monthly counts of eggs per gram (EPG) of feces, fecal cultures, packed cell volume (PCV), weight measurements, and collection of leaf mass from the pasture were performed. There was greater reduction in EPG, greater weight gain, and less infestation by infective larvae in the paddock of the Bioverm® group, compared with the control group (p < 0.05). There was no significant difference (p ≥ 0.05) in the mean PCV percentage between the Bioverm® and control groups. In coprocultures, Haemonchus sp. was the most prevalent helminth. Bioverm® (D. flagrans) was efficient for biological control of sheep gastrointestinal nematodes in the semiarid region of Brazil.

Individual and Combined Application of Nematophagous Fungi as Biological Control Agents against Gastrointestinal Nematodes in Domestic Animals

Gastrointestinal nematodes (GINs) are a group of parasites that threaten livestock yields, and the consequent economic losses have led to major concern in the agricultural industry worldwide. The high frequency of anthelmintic resistance amongst GINs has prompted the search for sustainable alternatives. Recently, a substantial number of both in vitro and in vivo experiments have shown that biological controls based on predatory fungi and ovicidal fungi are the most promising alternatives to chemical controls. In this respect, the morphological characteristics of the most representative species of these two large groups of fungi, their nematicidal activity and mechanisms of action against GINs, have been increasingly studied. Given the limitation of the independent use of a single nematophagous fungus (NF), combined applications which combine multiple fungi, or fungi and chemical controls, have become increasingly popular, although these new strategies still have antagonistic effects on the candidates. In this review, we summarize both the advantages and disadvantages of the individual fungi and the combined applications identified to date to minimize recurring infections or to disrupt the life cycle of GINs. The need to discover novel and high-efficiency nematicidal isolates and the application of our understanding to the appropriate selection of associated applications are discussed.

Bioverm® in the Control of Nematodes in Beef Cattle Raised in the Central-West Region of Brazil

Cooperia, Haemonchus and Oesophagostomum are the genera of gastrointestinal parasitic nematodes most prevalent in cattle and constitute a serious problem in cattle breeding due to the impact they have on meat and milk production and the high costs of control measures. The objective of the present work was to evaluate the efficiency of Bioverm^® (Duddingtonia flagrans) in the control of gastrointestinal parasitism of young cattle raised in the field, in the Central-West region of Brazil. The experiment was conducted on a farm located in the municipality of Jangada, MT, where 18 cattle, Nelore and Aberdeen Angus breeds, aged six to ten months, were randomly divided into two groups (treated group and control group) and distributed in paddocks of Brachiaria decumbens, naturally infested by larvae of gastrointestinal nematodes. The animals in the treated group received 1g of Bioverm^® for each 10 kg of body weight, administered daily with commercial feed, throughout a period of six months. In the control group, each animal received 1 g of rice bran for each 10 kg of body weight, without Bioverm^®, added to the feed. Stool and pasture samples were collected every two weeks. The treated group showed a significant reduction (p < 0.05) in values of eggs per gram of feces (EPG) and a significant gain of body weight (p < 0.05) when compared to the control group. The fungal formulation Bioverm^® was effective in pasture decontamination and consequently in reducing the occurrence of reinfection by nematodes. The animals treated with Bioverm^® showed a lower parasitic load and greater weight gain.

The efficacy of predatory fungi on the control of gastrointestinal parasites in domestic and wild animals-A systematic review

BACKGROUND

Gastrointestinal parasites like nematodes are associated with significant impacts on animal health, causing poor growth rates, diseases and even death. Traditional parasite control includes the use of anthelmintic drugs, albeit being associated with drug resistance and ecotoxicity. In the last decade, biological control of parasites using nematophagous or predatory fungi has been increasingly studied, although systematic evidence of its efficacy is still lacking. The aim of this work was to assess the evidence of efficacy of nematophagous fungi in the control of nematodes and other gastrointestinal parasites in different animal species.

METHODS

Using the PICO method (Population, Intervention, Comparison and Outcomes), we performed a systematic review on the subject to search for original papers published between January 2006 and October 2019, written in English, and indexed in PubMed/Medline. Medical Subject Headings (MeSH) terms were used in the syntax. Papers were selected for detailed review based on title and abstract. Inclusion and exclusion criteria were applied, and relevant data were collected from the remaining papers.

RESULTS

The literature search retrieved 616 papers. Eighty-nine were submitted to a detailed review. In the end, 53 papers were included in the analysis. The studies were very heterogeneous, using different fungi, doses, frequency of administration, duration of treatment, host animals, and target parasites. Considering the 53 papers, 44 studies (83 % of the interventions) showed efficacy, with only 9 studies (17 %) showing no significant differences when compared to control.

CONCLUSION

With the increasing hazards of drug resistance and ecotoxicity, biological control with predatory fungi stands out as a good tool for future parasite management, whether as a complementary treatment or as an alternative to standard parasite control.

Nematode resistance to five anthelmintic classes in naturally infected sheep herds in Northeastern Brazil

Abstract This study aimed to evaluate the occurrence of nematode resistance to anthelmintics on sheep herds from the semi-arid region of Paraíba, Northeastern Brazil. Fecal Egg Count Reduction Test (FECRT) was carried out on 20 properties. In each herd, 30 animals were divided into five groups containing six animals each: group I, treated with albendazole 10%, 4 mg/kg; group II, ivermectin 0.08%, 0.2 mg/kg; group III, closantel 10%, 10 mg/kg; group IV, levamisole hydrochloride 5%, 5 mg/kg; and group V, monepantel 2.5%, 2.5 mg/kg. All treatments were administered orally as a single dose. Fecal samples were collected on days zero and 10 after treatment, to perform FECRT and coprocultures. Multiresistance was observed in all the properties; 95% had high resistance to albendazole, 85% to ivermectin, 80% to closantel, 40% to levamisole, and 45% to monepantel. On property 15, where monepantel was ineffective, a second FECRT for this anthelmintic was carried out 4 months after the first, resulting in 75% efficacy. Immediately after the FECRT result, two ewes were euthanized and necropsied, and Haemonchus contortus, Trichostrongylus axei, Trichostrongylus colubriformis, Oesophagostomum columbianum, and Trichuris ovis were recovered. It was concluded that the resistance of sheep gastrointestinal nematodes to antthelmintic, including monepantel, is high.

Implementation of Biological Control to the Integrated Control of Strongyle Infection among Wild Captive Equids in a Zoological Park

The integrated control of strongyles was assayed for a period of three years in wild equids (zebras, European donkeys, and African wild asses) captive in a zoo and infected by strongyles. During three years control of parasites consisted of deworming with ivermectin + praziquantel; equids also received every two days commercial nutritional pellets containing a blend of 10⁴ - 10⁵ spores of the fungi Mucor circinelloides + Duddingtonia flagrans per kg meal. Coprological analyses were done monthly to establish the counts of eggs of strongyles per gram of feces (EPG). The reductions in the fecal egg counts (FECR) and in the positive horses (PHR) were calculated fifteen days after deworming; the egg reappearance period (ERP) and the time elapsed from the previous deworming (TPD) were also recorded. Four anthelmintic treatments were administered during the assay, three times throughout the first 2 yrs, and another treatment during the last one. FECR values of 96-100% and 75-100% for the PHR were recorded. The ERP oscillated between eight and twenty-eight weeks, and the TPD ranged from four to eighteen months, increasing to the end of the trial. No side effects were observed in any of the equids. It is concluded that integrated control of strongyles among equids captive in a zoo can be developed by anthelmintic deworming together with the administration of pellets manufactured with spores of parasiticide fungi every two days.

Controle de parasitas gastrintestinais em ovinos e análise financeira de uma fazenda com sistema de pastejo rotacionado irrigado no semiárido nordestino

RESUMO: O sistema de pastejo rotacionado irrigado é uma alternativa para a ovinocultura do semiárido. No entanto, a maior limitante para sua implementação são as dificuldades para controlar as parasitoses gastrintestinais. Neste trabalho objetivou-se determinar medidas de manejo para o controle das helmintoses gastrintestinais de ovinos em pastejo rotacionado irrigado e fazer a análise econômica do sistema. O experimento foi realizado em uma fazenda no Munícipio de Belém do São Francisco, Pernambuco, no período de abril de 2013 a setembro de 2014, em um rebanho de 646 a 859 ovinos mestiços da raça Dopper com Santa Inês, criados em uma área de 12 ha de pastagem de capim coast cross (Cynodon dactylon) dividida em 24 piquetes. Para o pastejo os ovinos foram divididos em dois grupos, um de ovelhas paridas e outro de ovelhas secas e borregas de mais de dois meses, que pastejavam três dias em cada piquete. Os piquetes tinham 36 dias de descanso. Foi feito teste de resistência aos anti-helmínticos no início de experimento e anualmente, que resultou na mudança anual do produto utilizado. No segundo ano, para as coletas de fezes e para o tratamento anti-helmíntico seletivo, as ovelhas paridas e as ovelhas secas foram divididas em dois subgrupos cada: paridas gordas, paridas magras, secas magras e secas gordas. Todos os meses coletavam-se fezes de 10% dos ovinos de cada subgrupo para fazer OPG e coprocultura. Cada grupo era tratado quando apresentavam média de mais de que 1000 OPG. Coletaram-se amostras de capim a cada dois meses para fazer a contagem e identificação de larvas do pasto. Durante os 18 meses de estudo foram tratados individualmente aproximadamente 3797 ovinos, equivalente a 6,49 tratamentos por ovino (3,97 em 2013 e 2,52 em 2014). O helminto mais prevalente nas coproculturas (50-85%) e no pasto (83,2%) foi Haemonchus contortus. Os menores números de larvas infectantes no pasto (94 a 111 larvas L3/ kg MS) ocorreram nos dias 35 e 2 a 8 de pastejo e os maiores números entre os dias 17 a 20 (374 a 761 L3/kg MS). A produção de carne da fazenda foi 1023 kg por hectare e a rentabilidade de 3,31%. Conclui-se que o pastoreio dos potreiros por três dias, com um descanso de 36 dias, com a utilização de tratamento seletivo, permite controlar as helmintoses gastrintestinais em sistemas de pastoreio rotacional irrigado. No entanto, é necessário realizar testes de resistência dos parasitas aos anti-helmínticos anualmente para contornar esse problema.

In Vitro Lethal Activity of the Nematophagous Fungus Clonostachys rosea (Ascomycota: Hypocreales) against Nematodes of Five Different Taxa

This study was aimed to evaluate the in vitro lethal activity of the nematophagous fungi Clonostachys rosea against 5 nematodes species belonging to different taxa. Two groups of 35 Petri dishes (PD) each were divided into 5 series of 7 (PD). Group 1 (series 1, 2, 3, 4, and 5) contained only water agar; meanwhile group 2 plates (series 6, 7, 8, 9, and 10) contained C. rosea cultures growth on water agar. Every plate from the two groups was added with 500 nematodes corresponding to the following genera/specie: Haemonchus contortus, Caenorhabditis elegans, Rhabditis sp., Panagrellus redivivus, and Butlerius sp. After 5-day incubation at room temperature, free (nontrapped) larvae were recovered from plates using the Baermann funnel technique. Recovered nematodes were counted and compared with their proper controls. Results shown an important reduction percentage of the nematode population attributed to the fungal lethal activity as follows: H. contortus (L₃) 87.7%; C. elegans 94.7%; Rhabditis sp. 71.9%; P. redivivus 92.7%; and Butlerius sp. 100% (p ≤ 0.05). The activity showed by C. rosea against the H. contortus can be crucial for further studies focused to the biological control of sheep haemonchosis, although the environmental impact against beneficial nematodes should be evaluated.

Control of sheep gastrointestinal nematodes using the combination of Duddingtonia flagrans and Levamisole Hydrochloride 5

The objective was to evaluate the action of D. flagrans pellets in association with Levamisole Hydrochloride 5% for controlling sheep gastrointestinal nematodes in the northeastern Brazil. Three groups of six sheep each were formed: group 1 received 3 g of the pellets (0.6 g of D. flagrans mycelium) for each 10 kg b.w., twice a week for six months, and deworming with Levamisole Hydrochloride 5% when EPG ≥ 1500; group 2 received a dosage of Levamisole Hydrochloride 5% when EPG ≥ 1500; and group 3 received 3 g of pellets without fungi for each 10 kg b.w., twice a week for six months. EPG counts, larval cultures, packed cell volume (PCV) and weighing were performed every 15 days; monthly, samples of grass from each paddock were collected. The mean EPG of the groups began to statistically differ from day 30 (p < 0.05). Group 1 required less deworming with Levamisole Hydrochloride 5% and showed superiority of PCV values ​​throughout the experiment (p < 0.05). There was a significant reduction (p < 0.05) in L3 recovery in the group 1 paddock from day 30 onwards. The use of D. flagrans pellets in association with Levamisole Hydrochloride 5% was effective for controlling gastrointestinal nematodes.

Efficacy of Clonostachys rosea and Duddingtonia flagrans in Reducing the Haemonchus contortus Infective Larvae

The biocontrol is proven effective in reducing in vitro and in situ free-living stages of major gastrointestinal helminths, allowing progress in reducing losses by parasitism, maximizing production, and productivity. This study aimed at evaluating the predatory activity of fungal isolates of Duddingtonia flagrans and Clonostachys rosea species and its association on infective larvae (L₃) of H. contortus in microplots formed by grasses and maintained in a protected environment. All groups were added with 10 mL of an aqueous suspension with 618 H. contortus L₃ approximately. Group 1 was used as control and only received the infective larvae. Groups 2 and 3 received D. flagrans chlamydospores and C. rosea conidia at doses of 5 × 10⁶. Group 4 received the combination of 5 × 10⁶ D. flagrans chlamydospores + 5 × 10⁶ C. rosea conidia. D. flagrans and C. rosea showed nematicidal effectiveness reducing by 91.5 and 88.9%, respectively, the population of H. contortus L₃. However, when used in combination efficiency decreased to 74.5% predation of H. contortus L₃. These results demonstrate the need for further studies to determine the existence of additive effects, synergistic or antagonistic, between these species.

Evaluation of the effectiveness of Duddingtonia flagrans and Monacrosporium thaumasium in the biological control of gastrointestinal nematodes in female bovines bred in the semiarid region

Brazil has a herd of 212 million cattle and 171 million hectares of pastures that produce approximately 96 % of Brazilian beef. The Brazilian production system enables animal infection by endoparasites, which are considered one of the main obstacles for the development of this industry and are responsible for considerable economic losses. The control of parasitic diseases is performed via the administration of antiparasitic drugs, but they leave residues of the products in the treated animal, affect non-target organisms and select resistant strains of the parasites. The species D. flagrans and M. thaumasium are promising and sustainable alternatives for controlling gastrointestinal helminths of ruminants and other herbivores. In this study, we evaluated the efficacy of isolates of these species, formulated in a sodium alginate matrix and administered twice a week, to reduce the number of environmental infective larvae of gastrointestinal nematodes that affect prepubescent zebu females. The treated animals presented fewer eggs and a lower number of infective larvae per gram of faeces (p < 0.05). The pastures occupied by treated animals showed a statistically significant reduction (p < 0.05) of the number of L3 and, furthermore, the genera Cooperia sp., Haemonchus sp., and Oesophagostomum sp. were the most prevalent. The average weight of the animals did not differ statistically (p > 0.05) among the treated and control groups. The use of sodium alginate pellets as vehicle for delivery of the fungus mycelia D. flagrans (isolate AC001) and M. thaumasium (isolate NF34A) proved effective in controlling trichostrongylids in prepubescent cows bred in the semi-arid region, with an effective reduction in the number of infective larvae in the pastures.

Prevalence and risk factors associated with goat gastrointestinal helminthiasis in the Sertão region of Paraíba State, Brazil

Gastrointestinal helminthiasis represents an obstacle to goat raising, causing severe damage to herds such as growth retardation, weight loss, and even death. In this study, we aimed to determine the prevalence and risk factors associated to goat gastrointestinal helminthiasis in the Sertão region of Paraíba State, Brazil. A total of 256 goats from 54 farms were systematically sampled. Blood and fecal samples were collected from each animal for egg per gram (EPG), larval culture, and packed cell volume (PCV) analyses. We found that 79.3% of the goats investigated were parasitized with gastrointestinal helminths. Significant correlation (p = 0.004) was observed between the EPG and PCV of the animals studied, and it was observed that the EPG increases as the PCV decreases. In the larval culture, the most prevalent helminth was Haemonchus sp. (83.2%). Age and sex were significant variables (p ≤ 0.20) for the development of gastrointestinal helminths: 86.8% of animals over 36 months of age and 81.7% of females were infected. The variable type of animal exploitation was also significant, with 90.3% (p ≤ 0.20) of the animals presenting double suitability (milk and meat). The Sertão region of Paraíba State presents high prevalence of gastrointestinal helminthiasis in goats, and age and type of animal exploitation are the most relevant risk factors to the development of these parasites.

Seasonal variations of EPG Levels in gastro-intestinal parasitic infection in a southeast asian controlled locale: a statistical analysis

We present a data based statistical study on the effects of seasonal variations in the growth rates of the gastro-intestinal (GI) parasitic infection in livestock. The alluded growth rate is estimated through the variation in the number of eggs per gram (EPG) of faeces in animals. In accordance with earlier studies, our analysis too shows that rainfall is the dominant variable in determining EPG infection rates compared to other macro-parameters like temperature and humidity. Our statistical analysis clearly indicates an oscillatory dependence of EPG levels on rainfall fluctuations. Monsoon recorded the highest infection with a comparative increase of at least 2.5 times compared to the next most infected period (summer). A least square fit of the EPG versus rainfall data indicates an approach towards a super diffusive (i. e. root mean square displacement growing faster than the square root of the elapsed time as obtained for simple diffusion) infection growth pattern regime for low rainfall regimes (technically defined as zeroth level dependence) that gets remarkably augmented for large rainfall zones. Our analysis further indicates that for low fluctuations in temperature (true on the bulk data), EPG level saturates beyond a critical value of the rainfall, a threshold that is expected to indicate the onset of the nonlinear regime. The probability density functions (PDFs) of the EPG data show oscillatory behavior in the large rainfall regime (greater than 500 mm), the frequency of oscillation, once again, being determined by the ambient wetness (rainfall, and humidity). Data recorded over three pilot projects spanning three measures of rainfall and humidity bear testimony to the universality of this statistical argument.