Mixed Grazing and Dietary Supplementation Improve the Response to Gastrointestinal Nematode Parasitism and Production Performances of Goats

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.

Formulating Parasiticidal Fungi in Dried Edible Gelatins to Reduce the Risk of Infection by Trichuris sp. among Continuous Grazing Bison

Control of infection by gastrointestinal nematodes remains a big problem in ruminants under continuous grazing. For the purpose of decreasing the risk of infection by Trichuris sp. in captive bison (Bison bison) always maintained in the same plot, dried gelatins having ≥106 chlamydospores of both Mucor circinelloides and Duddingtonia flagrans were given to them for one week, and at the end, fecal samples (FF) collected each week for four weeks were analyzed immediately. Feces taken one week prior to gelatin administration served as controls (CF). Eggs of Trichuris sp. were sorted into non-viable and viable, then classified into viable undeveloped (VU), viable with cellular development (VCD), or viable infective (VI). Ovistatic and ovicidal effects were determined throughout the study. In FF, viability of Trichuris eggs decreased between 9% (first week) and 57% (fourth week), egg development was delayed during the first two weeks, and VI percentages were significantly lower than in CF (p = 0.001). It is concluded that the preparation of gelatins with chlamydospores of parasiticidal fungi and their subsequent dehydration offer an edible formulation that is ready to use, stress-free to supply, and easy to store, as well as being well-accepted by ruminants and highly efficient to reduce the risk of Trichuris sp. infection among animals under continuous grazing regimes.

Anthelmintic resistance in soil-transmitted helminths: One-Health considerations

The One-Health approach recognizes the intricate connection between human, animal, and environmental health, and that cooperative effort from various professionals provides comprehensive awareness and potential solutions for issues relating to the health of people, animals, and the environment. This approach has increasingly gained appeal as the standard strategy for tackling emerging infectious diseases, most of which are zoonoses. Treatment with anthelmintics (AHs) without a doubt minimizes the severe consequences of soil-transmitted helminths (STHs); however, evidence of anthelmintic resistance (AR) development to different helminths of practically every animal species and the distinct groups of AHs is overwhelming globally. In this regard, the correlation between the application of anthelmintic drugs in both human and animal populations and the consequent development of anthelmintic resistance in STHs within the context of a One-Health framework is explored. This review provides an overview of the major human and animal STHs, treatment of the STHs, AR development and drug-related factors contributing towards AR, One-Health and STHs, and an outline of some One-Health strategies that may be used in combating AR.

Grassland biodiversity and ecosystem functions benefit more from cattle than sheep in mixed grazing: A meta-analysis

Grasslands have been widely grazed for livestock production by cattle and sheep. However, previous studies have mainly focused on the impacts of single-species grazing on grassland biodiversity and ecosystem functions; the effects of mixed grazing of cattle and sheep remain largely unknown. We conducted a meta-analysis to examine the impacts of mixed grazing and analyzed the relative roles of cattle and sheep on grassland biodiversity and multiple ecosystem functions. Mixed grazing studies mainly originated from Europe, the USA, and China. Generally, cattle and sheep exhibited distinctive impacts on grassland biodiversity and functions in single-species and mixed grazing regimes. Cattle grazing alone increased plant diversity and soil organic carbon content (SOC), while sheep grazing alone had little impact. Compared to single-species grazing, mixed grazing generally increased plant density and richness of insect herbivores and decreased soil nematode richness, but did not alter plant biomass, soil nitrogen, or nematode abundance. Cattle in the mixed grazing regime increased plant diversity, biomasses of forbs and legumes, SOC, and liveweight gains of livestock. The mixed grazing impacts were further regulated by climate conditions, grazing intensity, and grazing duration. Our findings provide compelling evidence that mixed grazing benefits biodiversity, soil carbon sequestration, livestock production, and community structure of grasslands, and cattle are more influential than sheep in creating the benefits of mixed grazing for sustainable management of grasslands.

Understanding Animal-Plant-Parasite Interactions to Improve the Management of Gastrointestinal Nematodes in Grazing Ruminants

Grazing systems have great potential to promote animal welfare by allowing animals to express natural behaviours, but they also present risks to the animals. Diseases caused by gastrointestinal nematodes are some of the most important causes of poor ruminant health and welfare in grazing systems and cause important economic losses. Reduced growth, health, reproduction and fitness, and negative affective states that indicate suffering are some of the negative effects on welfare in animals infected by gastrointestinal nematode parasitism. Conventional forms of control are based on anthelmintics, but their growing inefficiency due to resistance to many drugs, their potential for contamination of soil and products, and negative public opinion indicate an urgency to seek alternatives. We can learn to deal with these challenges by observing biological aspects of the parasite and the host’s behaviour to develop managements that have a multidimensional view that vary in time and space. Improving animal welfare in the context of the parasitic challenge in grazing systems should be seen as a priority to ensure the sustainability of livestock production. Among the measures to control gastrointestinal nematodes and increase animal welfare in grazing systems are the management and decontamination of pastures, offering multispecies pastures, and grazing strategies such as co-grazing with other species that have different grazing behaviours, rotational grazing with short grazing periods, and improved nutrition. Genetic selection to improve herd or flock parasite resistance to gastrointestinal nematode infection may also be incorporated into a holistic control plan, aiming at a substantial reduction in the use of anthelmintics and endectocides to make grazing systems more sustainable.

Prevalence and resistance to gastrointestinal parasites in goats: A review

Gastrointestinal parasitism, particularly nematode infection, is a major health issue affecting goats worldwide, resulting in clinical diseases and productivity loss. Prevalent gastrointestinal parasites (GIPs) affecting goats in South Africa are the Strongyloides papillosus, Eimeria spp., and Strongyles, especially the Haemonchus contortus and Trichostrongylus spp. According to the issues discussed in this paper and by other authors, the prevalence and intensity of various GIPs vary with an animal's location, breed, age, sex, and season. Because GIPs easily develop resistance to chemical treatment, selecting and breeding genetically GIP-resistant animals would be a relatively simple and inexpensive strategy for reducing or eliminating the current reliance on chemotherapy. Potential phenotypic indicators for selecting GIP-resistant goats include parasitological, immunological, and pathological phenotypic markers. Synergistic use of these indicators should be encouraged for a more accurate simplified genotype selection of resistant animals. Genes with Mendelian inheritance, particularly those involved in immunoregulatory mechanisms, have been identified in goats. Exploring this knowledge base to develop cost-effective molecular tools that facilitate enhanced genetic improvement programs is a current challenge. Future statistical and biological models should investigate genetic variations within genomic regions and different candidate genes involved in immunoregulatory mechanisms, as well as the identification of single nucleotide polymorphisms known to affect GIP infection levels.

Welfare of Native Goat Breeds in Serbia-Emphasis on Parasitological Infections

Native goat breeds in Serbia has been recognized as an important element of regional agrobiodiversity and play an important role in the safeguarding of cultural and traditional heritage. The aim of this study was to identify the main welfare issues likely to be encountered in extensive goat farming systems with an emphasis on parasitological infections. The study was conducted during the winter season on four small farms of native Balkan and Serbian white goats. For welfare assessment, animal-based indicators from AWIN protocol for goats were used. All fecal samples for parasites were qualitatively and quantitatively examined. The main welfare issues identified were poor hair coat condition (62.79%), dirty and light soiling hindquarters (31.40%), thin body condition score (26.74%), abscesses (19.78%), and udder asymmetry (18.60%). In addition, an important and prevalent welfare problem identified across all farms was parasite infection and weak significant (p < 0.001) correlation between certain parasites (Strongylidae, Moniezia spp., Buxtonella sulcate, and Protostrongylidae) and welfare indicators such as poor hair coat condition and nasal discharge. The results of this study provided the first overview and valuable insight into the impact of extensive systems on the welfare of native goats in the Balcan region.