Gastrointestinal Nematode Infections Research Articles

Variability in the Response against Teladorsagia circumcincta in Lambs of Two Canarian Sheep Breeds

The increasing resistance to anthelmintics has necessitated the exploration of alternative control strategies of gastrointestinal nematode (GIN) infections. A sustainable option is genetic selection based on differences in susceptibility to GIN infection between and within breeds of sheep. Here, three-month-old Canaria Hair breed (GIN-resistant) and Canaria Sheep breed (GIN-susceptible) showed no significant between-breed differences after trickle infection with Teladorsagia circumcincta, whereas considerable individual variability was found in both breeds. Next, data from lambs of both breeds were used to explore the relationships between parasitological variables and T. circumcincta-specific IgA levels, local immune cell populations, and abomasal lymph node gene expression to understand the possible mechanisms underlying resistance. Mucosal IgA levels as well as numbers of globular leukocytes and MHC-II+ cells were associated with protection. Analysis of lymph node gene expression revealed the associations between lower parasite numbers and cumulative fecal egg counts and several immune pathways, such as leukocyte cell adhesion, activation and differentiation of T cells, in particular CD4+ and IL-4 production. The data obtained here may inform on the relationship between phenotypic resistance variability and protective responses at the humoral, cellular, and transcriptomic levels, thus contributing to identifying immune responses in young lambs that could be used as markers for selection.

Relationships between sheep nematode infection, nutrition, and grazing behavior on improved and semi-natural pastures

Gastrointestinal nematodes (GINs) are key parasites of grazing sheep worldwide. To understand the factors influencing GIN infections, we examined the relationships among infection and nutrition, foraging behavior, and animal performance. Further, the parasitism and nutrition of sheep between improved and semi-natural pastures in Japan were compared. Sheep were grazed for 1 month each, first on an improved and then on a semi-natural pasture. Afterward, vegetation surveys, forage analyses, and (plant) nematode larval counts were conducted in both pastures, and fecal egg counts, biochemical analyses, and bite counts were completed for each sheep. The semi-natural pasture had diverse plant species, though it contained less crude protein, and nematode larvae were rarely observed on bamboo. Consequently, fecal egg per gram decreased after grazing on the semi-natural pasture. White blood counts, hematocrit, and glucose also decreased and body weight increased after grazing on this pasture. Principal component and correlation analyses revealed a significant relationship between GIN infection and behavior, but not between nutrition and either behavior or infection. As parasitized animals may become more aggressive feeders to compensate for their reduced nutritional uptake, grazing sheep on semi-natural pastures may facilitate more stable performance due to the lower risk of nematode infection from wild plants.

Characterization of interferon gamma gene in relation to immunological responses in Haemonchus contortus resistant and susceptible Garole sheep.

Garole sheep exhibits within-breed difference in resistance to natural gastrointestinal nematode infection predominated by Haemonchus contortus. In the present study, interferon gamma gene (IFN-γ) was characterized in relation to parasitological, haematological, and immune response against H. contortus in resistant and susceptible Garole sheep. Resistant and susceptible Garole sheep were selected from the field based on consistent low faecal egg counts (FEC) for one year and single nucleotide polymorphisms (SNPs) in the IFN-γ gene. The partial amplification of IFN-γ gene (1282bp) revealed 4 SNPs exclusively in resistant sheep and 3 SNPs were shared between resistant and susceptible Garole sheep. The selected resistant and susceptible Garole sheep were challenged with H. contortus infection. The parasitological, haematological, immunological responses, and expression of IFN-γ gene were compared between the resistant and susceptible Garole sheep. The FEC of resistant sheep was significantly (P < 0.05) lower than the susceptible sheep infected with H. contortus. There was spontaneous elimination of H. contortus from 28 to 33days post infection (DPI) in resistant sheep. Haemoglobin and packed cell volume were significantly (P < 0.05) higher in resistant sheep than the susceptible sheep. The serum concentration of immunoglobulin (Ig)G1 and IgA and cytokine IFN-γ activity and also the expression of IFN-γ gene were significantly (P < 0.05) higher in the infected resistant sheep from 14 to 28 DPI compared to the susceptible sheep. In resistant sheep, IgA and IgG1 and cytokine IFN-γ positively correlated with expression of IFN-γ gene, and the SNPs recorded in the resistant sheep only might play an important role in conferring resistance against H. contortus. Further studies are required to elucidate the role of IFN-γ gene in H. contortus resistance in Garole sheep.

Review on Hook Worm Infections : Ancylostomiasis

The present review mainly highlighted on hookworm infections and the Ancylostoma species distribution, infection rate, epidemiology, prevalence, pathophysiology, diagnosis and treatments were analyzed. Hook Worms are located in the intestinal tract and/or tissues. Several investigations have reported the interesting phenomenon that the infective larvae of canine hookworm, Ancylostoma canium and other species. The immune response to worm infections also depends upon the location of infestation. Gastrointestinal nematode infections have always been a major animal health problem of domestic animals and/or ruminant livestock. Hosts with nematode infections present a series of pathological effects these changes include tissue damage, alterations in blood constituents, elevation or decrease of enzymatic levels. Hookworm diseases are most common in tropical and subtropical climatic conditions and the infections were observed in both animals and humans. As per the available information globally more than 740 million peoples are infected with hookworm. In sub-Saharan Africa, Asia, approximately 200 million people have been infected with hookworm, 90 million of them were children. The main objective of this review was to identify the prevalence, epidemiology and determinant factors of hookworm infection. Diagnostic methods that differentiate between hookworm species, including molecular methods, need to be developed for widespread use in control programmes to elucidate key features of hookworm epidemiology and control.

The impact of sire fecal egg count estimated breeding values on indicators of offspring gastrointestinal nematode infection, and relative impact of lamb estimated breeding values on sale value of ram lambs

Genetic selection of sheep for resistance to gastrointestinal nematodes (GIN) has become a priority for pasture-based production of lambs to minimize the need for deworming. The objective of this experiment was to determine the impact of sire weaning or post-weaning fecal egg count (FEC) estimated breeding value (EBV; WFEC and PFEC, respectively) from the National Sheep Improvement Program (NSIP) on GIN infection in Katahdin lambs born in fall (Oct – Nov; n = 459) or winter (Jan – Feb; n = 378) of 2018 through 2021 at the USDA Agricultural Research Service (ARS). FAMACHA scores were determined, and blood samples and feces were collected from the lambs to determine packed cell volume (PCV), and FEC at 60, 90, 120, and 150 days of age, and lambs were selectively dewormed if anemic. Data were analyzed using mixed models containing fixed effects of year, sex, age at sampling (fitted as a repeated measure), and their interactions, and continuous effects of sire FEC EBV. The FEC and PCV of offspring was positively (P < 0.001) and negatively (P < 0.001), respectively, related to the sire WFEC and PFEC. A second objective was to examine effects on sale prices of breeding-quality ram lambs from four farms, including ARS, of lamb EBV for WFEC and a ewe productivity trait (EPT) designed to identify ewes with superior maternal ability. Sale price effects were dominated by sale type with a premium of $1086/head relative to direct sales from the farm for animals in NSIP or Katahdin Hair Sheep International Expo sales. Producers likewise assigned a premium of $107/head to animals retained for use in their own breeding herds. The next most impactful variable was the EPT EBV. A 1-SD increase of 2.3 units in EPT yielded an extra $39/head whereas a similar 1-SD decrease in EPT resulted in a $32/head discount. Lambs born in fall were discounted by $6/head relative to those born in winter. Lambs that were not dewormed received a $29/head premium over lambs that were dewormed and was presumably taken as a phenotypic signal that the lamb was resistant. A ± 1-SD change in WFEC had no effect on sale value, which changed by less than $0.01/head. This result may have been confounded with whether or not the lamb had been dewormed. Thus, while more parasite-resistant sires produced offspring with lower FEC, the sale value of these ram lambs appeared to have been more strongly associated with other EBV such as EPT or with a desire to obtain ram lambs with balanced EBV rather than elite EBV for parasite resistance.

Potential of Anthelmintic Herbal Drugs against Gastrointestinal Nematodes in Farm Animals: A Review

Gastrointestinal (GI) nematode infections are one of the most prevalent and significant problems in livestock worldwide. This study aimed to review the potential of anthelmintic herbal drugs against gastrointestinal nematodes in farm animals. Anthelmintic drugs are the most common method of controlling GI nematodes since they are simple, cheap, and provide therapeutic and prophylactic protection. However, the problem has become complicated due to the emergence of resistance to anthelmintic drugs because anthelmintic drugs are used indiscriminately to treat parasitic diseases. Anthelmintic resistance in GI nematodes of ruminants is a global problem. Many domestic animals possess multi-class resistance to all classes of anthelmintics. Synthetic anthelmintics could be unsafe as they can cause side effects and toxicity. Therefore, plants are used to develop and discover novel substances acting as anthelmintics. Herbal drugs have become increasingly popular because of their fewer side effects in recent years. Consequently, the demand for herbal formulations of anthelmintic drugs is increasing. The development of instrumental analysis accelerates the preparation of phytochemical constituents and their standardization, and this field is becoming critical for research.

PSX-B-11 Classification Performance of Multinomial Logistic Regression for Identifying Resistance, Resilience, and Susceptibility to Gastrointestinal Nematode Infections in Sheep

Abstract The objective was to investigate the feasibility of using easy-to-measure phenotypic traits to predict resistant, resilient and susceptible sheep to gastrointestinal nematodes via multinomial logistic regression (MLR). The database comprised 3,654 records on 1,250 Santa Ines sheep from six farms. The animals were classified into three responses to infection classes (resistant, resilient and susceptible) according to fecal egg count and packed cell volume. The MLR was used to predict such classes using the information of age, month of record, sex, Famacha degree, weight and body condition score as predictors, and a leave-one-farm-out cross-validation technique was used to assess prediction quality across farms. The MLR was able to predict with satisfactory performance the resistant and susceptible animals in two of the farms, with resistant precision equal to 79 and 77%, and susceptible recall equal to 68 and 83%, respectively. In addition, at least one of the classes was well predicted in four farms, with susceptible recall equal to 71 and 89% in two of these farms, and resistant precision equal to 86 and 100% in the other two farms. The model was not able to satisfactorily classify resilient class. The proposed approach could help attenuate the negative impacts related to infections caused by gastrointestinal nematodes, contributing to design deworming strategies that take into account the risk of an animal being contaminated, consequently reducing the costs with anthelmintic administration and laboratory analyses based on blood or fecal samples. The results suggest that the use of easily measurable traits may provide useful information for supporting management decisions on the farm level that could potentially contribute to reducing parasitic contamination and production costs. In addition, the animals identified as resistant can also be incorporated as selection candidates into breeding programs for genetic improvement of flocks.Supported by the São Paulo Research Foundation (FAPESP) grants #2020/03575-8, #2018/01540-2 and #2016/14522-7, SP, Brazil.

Associations between Gastrointestinal Nematode Infection Burden and Lying Behaviour as Measured by Accelerometers in Periparturient Ewes.

Simple SummaryNovel sensor technologies have great potential to improve animal health and welfare on farms by identifying disease early in livestock. These technologies are yet to be widely applied in sheep flocks despite their great potential to aid control of costly disease such as those caused by parasitic infection. In this study, leg-attached accelerometer sensors recorded the behaviour of 54 ewes in late pregnancy, with the aim of discovering if gastrointestinal nematode (GIN) infection levels were associated with behavioural variation. It was found that ewes laid down more often on average when infected with increasing numbers of GIN. Each lying bout was also shorter in length on average in ewes infected with higher levels of GIN. The results demonstrate that ewe behaviour can be an indication of parasite infection levels, and thus automated monitoring of sheep behaviour could allow animals to be treated efficiently against GIN in the future, maximising animal health and minimising production losses.The application of precision livestock farming (PLF) technologies will underpin new strategies to support the control of livestock disease. However, PLF technology is underexploited within the sheep industry compared to other livestock sectors, and research is essential to identify opportunities for PLF applications. These opportunities include the control of endemic sheep disease such as parasitic gastroenteritis, caused by gastrointestinal nematode infections, which is estimated to cost the European sheep industry EUR 120 million annually. In this study, tri-axial accelerometers recorded the behaviour of 54 periparturient Welsh Mule ewes to discover if gastrointestinal nematode (GIN) infection burden, as measured by faecal egg count (FEC), was associated with behavioural variation. Linear mixed models identified that increasing FECs in periparturient ewes were significantly associated with a greater number of lying bouts per day and lower bout durations (p = 0.013 and p = 0.010, respectively). The results demonstrate that FECs of housed periparturient ewes are associated with detectable variations in ewe behaviour, and as such, with further investigation there is potential to develop future targeted selective treatment protocols against GIN in sheep based on behaviour as measured by PLF technologies.

Potential for silvopastoral systems to control nematode burden in livestock farming in winter rainfall areas of South Australia, Australia

Gastrointestinal nematode infections cause significant production losses in ruminants. In southern Australia, the estimated annual cost of internal parasites in sheep, cattle and goats are $436million, $82m and $2.54m, respectively. An over-reliance on anthelmintic treatments has resulted in anthelmintic resistance becoming an increasing concern for producers. Reducing the need for chemical anthelmintics is desirable to lower producer costs and limit the development of anthelmintic resistance. Condensed tannins found in many trees and forages are a plant secondary compound receiving considerable interest as an alternative anthelmintic strategy. Direct anthelmintic effects from condensed tannins are associated with the binding of larval proteins; slowing egg hatching, larval development and exsheathment. Indirect effects are associated with improvements to protein metabolism and immune function within the animal. Several native Australian tree extracts have demonstrated anthelmintic properties, but further research is required to assess their suitability for silvopastoral systems in South Australia.

Genome-Wide Association Study for Haemonchus contortus Resistance in Morada Nova Sheep.

Among the gastrointestinal nematodes affecting sheep, Haemonchus contortus is the most prevalent and virulent, resulting in health problems and production losses. Therefore, selecting sheep resistant to H. contortus is a suitable and sustainable strategy for controlling endoparasites in flocks. Here, 287 lambs of the native Brazilian Morada Nova hair sheep breed were subjected to two consecutive artificial infections with H. contortus and assessed for fecal egg count (FEC), packed cell volume (PCV), and live weight (LW). Forty-four animals ranked as having extreme resistance phenotypes were genotyped using the Illumina OvineSNP50v3 chip. A case–control genome-wide association study (GWAS) detected 37 significant (p < 0.001) markers in 12 ovine chromosomes in regions harboring quantitative trait loci (QTL) for FEC, Trichostrongylus spp. adults and larvae, weight, and fat; and candidate genes for immune responses, mucins, hematological parameters, homeostasis, and growth. Four single-nucleotide polymorphisms (SNP; OAR1_rs427671974, OAR2_rs419988472, OAR5_rs424070217, and OAR17_rs401006318) genotyped by qPCR followed by high-resolution melting (HRM) were associated with FEC and LW. Therefore, molecular markers detected by GWAS for H. contortus resistance in Morada Nova sheep may support animal selection programs aimed at controlling gastrointestinal nematode infections in flocks. Furthermore, genotyping of candidate genes using HRM qPCR may provide a rapid and efficient tool for animal identification.

Protein Supplementation as a Nutritional Strategy to Reduce Gastrointestinal Nematodiasis in Periparturient and Lactating Pelibuey Ewes in a Tropical Environment.

The study was carried out to evaluate the effect of energy and protein supplementation on parasitological and hematological response during peripartum and lactation of productive and non-productive Pelibuey ewes in a tropical environment. Forty-eight Pelibuey ewes aged 3–5 years and with a body weight of 31 ± 5 kg were used. Four groups of 12 ewes, including non-pregnant and productive ewes, were formed. A factorial treatment design was formulated, where two levels of energy (low, 9.6 MJ/kg, n = 24; and high, 10.1 MJ/kg, n = 24) and two levels of protein (high, 15% crude protein in diet, n = 24; and low, 8% crude protein in diet, n = 24) were studied. Fecal and blood samples were collected to determine the fecal egg count (FEC) of gastrointestinal nematodes (GIN), packed cell volume (PCV) and peripheral eosinophil (EOS) count. These variables were rearranged with respect to the lambing date in a retrospective study. The high dietary protein level had a significant effect on reducing the FEC and increasing the PCV of ewes during lactation, in comparison with animals fed with the low protein level. Differences in the study variables were attributed to physiological stage. Lactating ewes showed the highest FEC values (2709 ± 359 EPG), the lowest PCV values (21.9 ± 0.7%) and the lowest EOS (0.59 ± 0.6 Cells × 103 µL). It is concluded that high levels of dietary protein improve the hematological response and reduce the FEC in Pelibuey ewes under grazing conditions. The non-pregnant ewes maintained some resilience and resistance to GIN infection compared to productive ewes.

Organoids as tools to investigate gastrointestinal nematode development and host interactions.

Gastrointestinal nematodes are a diverse class of pathogens that colonise a quarter of the world’s human population and nearly all grazing livestock. These macroparasites establish, and some migrate, within host gastrointestinal niches during their life cycles and release molecules that condition the host mucosa to enable chronic infections. Understanding how helminths do this, and defining the molecules and mechanisms involved in host modulation, holds promise for novel strategies of anthelmintics and vaccines, as well as new knowledge of immune regulation and tissue repair. Yet the size and complexity of these multicellular parasites, coupled with the reliance on hosts to maintain their life cycles, present obstacles to interrogate how they interact with the gastric and intestinal epithelium, stroma and immune cells during infection, and also to develop protocols to genetically modify these parasites. Gastrointestinal organoids have transformed research on gastric and gut physiology during homeostasis and disease, including investigations on host-pathogen interactions with viruses, bacteria, protozoa and more recently, parasitic nematodes. Here we outline applications and important considerations for the best use of organoids to study gastrointestinal nematode development and interactions with their hosts. The careful use of different organoid culture configurations in order to achieve a closer replication of the in vivo infection context will lead not only to new knowledge on gastrointestinal nematode infection biology, but also towards the replication of their life cycles in vitro, and the development of valuable experimental tools such as genetically modified parasites.

Influence of silvopastoral systems on gastrointestinal nematode infection and immune response of Nellore heifers under tropical conditions

Among the strategies for integrating crops, livestock, and forestry, silvopastoral systems must be highlighted due to their inherent microclimatic conditions, mainly in tropical countries such as Brazil, where cattle are frequently subjected to unfavorable thermal conditions. However, according to some studies, shading can potentially worsen herds´ parasitism due to better microclimatic condition for the parasites. This study aimed to assess fecal egg count in Nellore heifers reared in two silvopastoral arrangements (pasture with single or triple tree rows), in a crop-livestock system, and open pasture. In the silvopastoral treatment composed of triple rows, lesser parasite burden means were found, with a peak infection in February/March and another in October. Regarding the effect of seasons over the year, there was an environmental influence on the egg counts, with higher averages during the late rainy season and the beginning of the dry season. An immunological investigation of animals from each group showed that cattle kept on the silvopastoral arrangements with either single or triple rows have significantly higher lymphocyte proliferation when stimulated with specific antigens than those kept on open pastures. Based on our results, it can be concluded that both silvopastoral systems were not considered as a risk factor for nematode egg counts in Nellore heifers. Indeed, the shadiest system promoted milder parasitism and higher immunological lymphocyte responses in animals.

Depicting Fecal Microbiota Characteristic in Yak, Cattle, Yak-Cattle Hybrid and Tibetan Sheep in Different Eco-Regions of Qinghai-Tibetan Plateau.

ABSTRACTThe gut microbiota is closely associated with the health and production performance of livestock. Partial studies on ruminant microbiota are already in progress in the Qinghai-Tibetan Plateau Area (QTPA) in China, but large-scale and representative profiles for the QTPA are still lacking. Here, 16S rRNA sequencing was used to analyze 340 samples from yak, cattle, yak-cattle hybrids, and Tibetan sheep, which lived in a shared environment from 4 eco-regions of the QTPA during the same season, and aimed to investigate the fecal microbiota community composition, diversity, and potential function. All samples were clustered into 2 enterotypes, which were derived from the genera Ruminococcaceae UCG-005 and Acinetobacter, respectively. Environment, human activity, species, and parasitization all affected the fecal microbiota. By assessing the relationship between the fecal microbiota and the above variables, we identified a scattered pattern of fecal microbiota dissimilarity based more significantly on diet over other factors. Additionally, gastrointestinal nematode infection could reduce the capacity of the bacterial community for biosynthesis of other secondary metabolites, carbohydrate metabolism, and nucleotide metabolism. Ultimately, this study provided a fecal microbiota profile for ruminants living in 4 eco-regions of the QTPA and its potential future applications in developing animal husbandry regimes.IMPORTANCE Cattle, yak, and sheep reside as the main ruminants distributed throughout most regions of Qinghai-Tibetan Plateau Area (QTPA) in China. However, there is a lack of large-scale research in the QTPA on their fecal microbiota, which can regulate and reflect host health as an internalized “microbial organ.” Our study depicted the fecal microbiota community composition and diversity of yak, cattle, yak-cattle hybrids, and Tibetan sheep from 4 eco-regions of the QTPA. Additionally, our results demonstrated here that the ruminant samples could be clustered into 2 enterotypes and that diet outweighed other factors in shaping fecal microbiota in the QTPA. This study provided a basis for understanding the microbiota characteristic of ruminants and its possible applications for livestock production in the QTPA.

Early Transcriptome Differences Between Pre-Infected and Naïve Kid Goats Infected With Haemonchus contortus.

In small ruminant production, gastrointestinal nematode (GIN) infection is one of the major causes of economic losses. The aim of this study was to compare the abomasal mucosa transcriptome of naïve and pre-infected goats at early time points after Haemonchus contortus infection, in order to identify different pathways and upstream regulators involved in the host immune response. Naïve and pre-infected Creole kids were orally infected with 10,000 H. contortus infective larvae (L3), and abomasal mucosa was sampled at 0, 4, and 6 days post-infection (dpi). At 6 dpi, all the animals were slaughtered to perform parasite burden counts. The mean number of L4 recovered in naïve kids was more than twice as high as that recovered in the pre-infected ones (5,860 and 2,474 respectively, p < 0.001). RNA-seq analysis showed a number of differentially expressed genes (DEGs) very low for both naïve and pre-infected animals when comparing day 0 vs. day 4 post-infection. A total of 2,237 and 3,206 DEGs were identified comparing 0 vs. 6 dpi in naïve and pre-infected animals, respectively. Interestingly, only 18 DEGs were found for the comparison of pre-infected vs. naïve animals at 6 dpi. Ingenuity pathway analysis (IPA) showed that several immune responses were activated in pre-infected compared with naïve animals at 0 and 4 dpi such as Th2 and Th1 pathways, natural killer cell, B cell receptor, IL-2, and IL-15 signaling. On the other hand, both naïve and pre-infected animals showed activation for those pathways comparing 6 vs. 0 dpi, with no difference between them. A similar pattern was recorded for upstream regulator genes which were related to immunity like TNF, IL-1β, IL-2, IL-5, TGFβ1, IFNγ, TCR, IL-18, IL-6, and IL-4. Our results showed that at 0 and 4 dpi the immune response was activated toward Th1 and Th2 pathways in pre-infected kids compared to the naïve ones, however, the same immune response was developed in naïve kids as earlier as 6 dpi. We conclude that repeated H. contortus infection in kid goats induced a concomitant early activation of a Th1 and Th2 immune response resulting in the regulation of worm establishment.

Prevalence of gastrointestinal helminths of small ruminants subjected to traditional livestock management system in Gadau district, Bauchi state Nigeria

Globally, parasitic diseases are one of serious concerns in production and management of livestock. African climate and other environmental factors constitute a favorable condition for the growth of gastrointestinal parasites in animals. This research work was aimed at assessment of prevalence of parasites infesting gastrointestinal tracks of goats and sheep at Gadau District, Northern Nigeria. The results reveal the overall prevalence of 42.7% gastrointestinal parasites in both goats and sheep in the study area. It indicates that sheep were less infected with gastrointestinal parasitic nematodes than the goats. It also revealed that the degree of incidence of gastrointestinal parasitic nematodes infection varies among the age, sex and species of small ruminants in the study area, due to the management system for the small ruminants.

Development of Bovine Gastric Organoids as a Novel In Vitro Model to Study Host-Parasite Interactions in Gastrointestinal Nematode Infections.

Gastro-intestinal nematode (GIN) parasites are a major cause of production losses in grazing cattle, primarily through reduced growth rates in young animals. Control of these parasites relies heavily on anthelmintic drugs; however, with growing reports of resistance to currently available anthelmintics, alternative methods of control are required. A major hurdle in this work has been the lack of physiologically relevant in vitro infection models that has made studying precise interactions between the host and the GINs difficult. Such mechanistic insights into the infection process will be valuable for the development of novel targets for drugs, vaccines, or other interventions. Here we created bovine gastric epithelial organoids from abomasal gastric tissue and studied their application as in vitro models for understanding host invasion by GIN parasites. Transcriptomic analysis of gastric organoids across multiple passages and the corresponding abomasal tissue showed conserved expression of tissue-specific genes across samples, demonstrating that the organoids are representative of bovine gastric tissue from which they were derived. We also show that self-renewing and self-organising three-dimensional organoids can also be serially passaged, cryopreserved, and resuscitated. Using Ostertagia ostertagi, the most pathogenic gastric parasite in cattle in temperate regions, we show that cattle gastric organoids are biologically relevant models for studying GIN invasion in the bovine abomasum. Within 24 h of exposure, exsheathed larvae rapidly and repeatedly infiltrated the lumen of the organoids. Prior to invasion by the parasites, the abomasal organoids rapidly expanded, developing a ‘ballooning’ phenotype. Ballooning of the organoids could also be induced in response to exposure to parasite excretory/secretory products. In summary, we demonstrate the power of using abomasal organoids as a physiologically relevant in vitro model system to study interactions of O. ostertagi and other GIN with bovine gastrointestinal epithelium.

In vitro anthelmintic activities of three ethnomedicinal plant extracts against Haemonchus contortus

Aim of study: To investigate the in vitro anthelmintic efficacies of three plants, Annona senegalensis (AS), Cochlospermum planchonii (CP), and Sarcocephalus latifolius (SL), used by livestock farmers in Northern Nigeria, to treat gastrointestinal nematode infections in ruminants. Area of study: Makurdi, Benue State, Nigeria. Materials and methods: The plants were selected through a structured questionnaire administered to livestock farmers in Northern Nigeria. Aqueous and acetone leaf (AS and SL) and root (CP) extracts of these plants were investigated for their anthelmintic activity against Haemonchus contortus using the egg hatch inhibition assay at concentration levels of 0.3125 to 10 mg/mL in 2.5% dimethyl sulfoxide. Main results: A probit log-dose response analysis showed that acetone extract of CP achieved 100% egg hatch inhibition similar to the commercial drug at all tested concentrations after 48 hours of incubation, while AS demonstrated 88.7% egg hatch inhibition. Acetone extract of SL had less than 50% egg hatch inhibition at all tested concentrations. On the other hand, the aqueous extract of CP and SL both exhibited 100% inhibition at 5 and 10 mg/mL of the tested concentrations, while AS had less than 50% egg hatch inhibition at all tested concentrations. Research highlights: This study identified CP, AS, and SL as medicinal plants with rich sources of molecules that have potential value in the development of novel anthelmintic drugs.

Maternal gastrointestinal nematode infection enhances spatial memory of uninfected juvenile mouse pups

The developing brain is particularly vulnerable to factors including maternal infection during pregnancy. Establishment of neural networks critical for memory and cognition begins during the perinatal period, when Heligmosomoides bakeri, a gastrointestinal (GI) nematode restricted to the maternal mouse intestine, has been shown to upregulate expression of long-term potentiation genes in the young rodent pup brain. We explored the impact of maternal infection during pregnancy and early lactation on the spatial behavior of uninfected male and female juvenile mice. Pre-weaned pups of H. bakeri infected dams exhibited less exploratory behaviour compared to pups of uninfected dams on postnatal day (PD) 16 but not PD 17, possibly reflecting a transient fear of an unfamiliar environment and/or a brief neurodevelopmental delay. Our two spatial memory tests show for the first time an enhancement of spatial memory in response to maternal nematode infection regardless of pup sex. At PD 17, pups of infected dams expressed object location memories after 3 h in the Object Location Test whereas offspring of uninfected mothers did not. In addition, at PD 34, juveniles of infected mothers retained their ability to find the escape hole in the Barnes Maze Test for one week whereas offspring from uninfected mothers did not. This finding is even more striking given that spatial memory was positively associated with pup length, yet this maternal infection impaired linear growth of pups. Thus, the positive impact of maternal infection on spatial memory countered any impairment associated with the shorter length of the pups. Overall, these novel findings indicate that a maternal GI nematode infection during pregnancy and lactation positively influences the spatial memory of uninfected juvenile offspring with potential fitness implications for the next generation.

Repeatability of Health and Welfare Traits and Correlation with Performance Traits in Dairy Goats Reared under Low-Input Farming Systems.

The objectives of the study were to estimate the repeatability of health and welfare traits and investigate their association with performance in three breeds of dairy goats reared under low-input farming systems in Greece. A total of 1210 goats of Eghoria (n = 418), Skopelos (n = 429), and Damascus (n = 363) breeds were assessed. Udder health, parasitic resistance, welfare, milk yield and quality, and body condition score were recorded monthly for two milking periods. Udder health records included somatic cell count (SCC) and total viable count (TVC). Based on combinations of SCC and TVC and thresholds set at >106 cells/mL and >2 × 104 cfu/mL, respectively, additional udder health phenotypes were defined. Parasitism included myiasis, tick infestation, gastrointestinal nematode (GIN) and cestode faecal egg count (FEC), and lungworm faecal larval count (FLC). Infection with each of the endoparasites was defined based on FEC/FLC. Welfare assessment parameters included the presence of ear and horn injuries, ocular and nasal discharge, body and udder abscesses, injury and lesions on the skin of different regions, diarrhoea, hernias, overgrown hooves, arthritis, lameness, and udder asymmetry. Trait repeatability and animal correlations were estimated. Significant (p < 0.05) repeatability was reported for all udder health and most welfare traits in all breeds, GIN and cestode FEC, and GIN and lungworm infection in Eghoria, and myiasis in Skopelos. Correlations of health and most of welfare traits with performance were non-significant or favourable. Overall, results demonstrate potential to improve health and welfare of the studied breeds without compromising performance.