Moredun Research Institute

Gastrointestinal nematodes (GIN) can impact on cattle health and welfare as well as cause economic losses associated with lower productivity but are often overlooked by farmers as a sub-clinical issue. Infections are routinely controlled with prophylactic use of anthelmintics but resistance to the available products has been reported. The prevalence of anthelmintic resistance (AR) in cattle GIN is advancing in certain species, making control more challenging. This study shows the current prevalence and diversity of GIN populations in British commercial cattle herds and the extent of infection in traded animals. Faecal samples were collected from 455 cattle herds; 395 from groups being sold through livestock auctions and a further 60 from samples submitted to the Animal and Plant Health Agency (APHA) for monitoring purposes. Faecal egg counts (FEC) were conducted on all samples and nematode eggs recovered for molecular species identification using Illumina MiSeq. Of the traded cattle, 67% had a positive faecal egg count, with a mean FEC of 20 eggs per gram (epg) (95% CI: 11 - 34). Samples from APHA had a mean FEC of 72 epg (95% CI: 56-93). Ostertagia ostertagi and Cooperia oncophora were the most common species identified, with co-infections of these two species found in 87% of samples. A diverse range of additional species were also identified, and these were found to vary with the pedigree status of cattle sampled and geographic location. Our results highlight that most cattle sold at auction were carrying GIN, which included a high prevalence of the pathogenic species O. ostertagi. These findings stress the need for effective biosecurity measures for new and returning cattle to minimise the movement of GIN between farms.

STEVEN McCulloch's recent article raises important and timely questions about the role of the veterinary profession in addressing climate change, public health and animal welfare (VR, 17/24 January 2026, vol 198, p 95). Few farm vets would dispute the scale of the challenges outlined, nor the need for science-led change across global food systems. Where many in the profession may wish to add nuance is in how those changes are framed, implemented and communicated – particularly in a UK context. Farm vets work at the intersection of animal health, food production and environmental stewardship every day. We see firsthand that ‘animal agriculture’ is not a single, homogeneous activity. Different farming systems have markedly different impacts, and UK livestock production – across ruminant, monogastric and mixed systems – operates within a very different environmental, regulatory and welfare framework from many intensive global models that often dominate international datasets. UK farmers manage around 70 per cent of the country's land, much of which is permanent pasture, unsuitable for cropping, but well suited to ruminant livestock. These systems can support biodiversity, maintain soil carbon, protect landscapes and convert grass into high-quality, nutrient-dense food. Alongside these land-based systems, other UK livestock sectors, including poultry, play a key role in providing affordable, efficient sources of high-quality protein within tightly regulated production frameworks. From a planetary health perspective, the issue is therefore not simply one of ‘less versus more’ meat, but of what kind of meat, produced how and where. Balanced diets that include appropriate amounts of meat and dairy are well supported by nutritional science, particularly when those foods are produced to high welfare and environmental standards. UK-reared meat has relatively low food miles for UK consumers. It is produced under some of the world's most stringent animal welfare and antimicrobial use regulations and is subject to continuous veterinary oversight. Across sectors, this includes ongoing efforts to improve environmental performance, such as reducing reliance on imported feed ingredients, improving feed efficiency, and lowering the carbon footprint of production systems. Replacing this food with imported alternatives – whether animal or plant based – risks exporting environmental impact rather than reducing it. Farm vets also recognise the progress already made. Antimicrobial use in UK livestock has fallen dramatically over the past decade, driven by close collaboration between farmers and vets, improved husbandry and better disease prevention. Welfare outcomes in many sectors have improved for the same reasons. These gains are rarely the result of blunt targets alone, but of sustained, sector-specific change supported by veterinary expertise. At a time of significant economic pressure on UK agriculture, it is also vital to consider resilience and food security. Supporting domestic production reduces reliance on imports from countries with lower welfare or environmental standards, helps maintain rural economies and preserves the skills and infrastructure needed to adapt farming systems for the future. This applies across all livestock sectors, including those with more intensive housing and supply chains that face distinct sustainability challenges. Championing UK farmers is not about protecting the status quo, but about enabling them to continue improving while remaining economically viable. The veterinary profession is well placed to lead a constructive, evidence-based conversation about sustainable diets – one that acknowledges the need for moderation, reduction of waste and improvement in production systems, while also recognising the value of responsibly produced animal-source foods. Many vets already advocate ‘less and better’ not as a defence of profit, but as a pragmatic route to higher welfare, lower environmental impact and better public trust. “Rather than framing the debate as a binary choice between meat reduction and professional integrity, there is an opportunity to emphasise shared objectives

Clostridioides difficile infection (CDI) is a toxin-mediated gastro-intestinal disease. Yet, C. difficile is a phylogenetically diverse species that includes many non-toxigenic strains. In general, these are understudied, despite having significant potential impact for our understanding of the colonization process and as therapeutic modalities. Here, we present an in-depth characterization-including the complete genome sequence-of the non-toxigenic C. difficile strain L-NTCD03. This strain belongs to PCR ribotype 416, clade 4 and multilocus sequence type 39. It is resistant to multiple antimicrobials, but not those used for treatment of CDI. We validated the relevance of the cfr(B) gene from this strain in antimicrobial resistance to clindamycin, linezolid, retapamulin, and streptogramin A. We found the L-NTCD03 strain to be non-toxic in various assays. Altogether, L-NTCD03 is a promising candidate for developing into a live biotherapeutic product.

Abstract Background Q fever is a zoonotic disease with virtually worldwide dissemination. Its bacterial agent, Coxiella burnetii , is primarily found in cattle and small ruminants. Disease manifestation is highly variable, i.e. asymptomatic, acute or chronic in humans, and subclinical or present as reproductive disorders in ruminants. Different genomic lineages of C. burnetii have been recognized and are considered to show host preferences and influence the disease outcome. The virulence of C. burnetii is essentially determined by effector proteins that modulate host cell processes, allowing the bacterium to persist and proliferate in the host. Thus, these effectors have been suggested to play a role in the presumed host specificity and disease manifestation. Results In the present study, a comprehensive set of 140 C. burnetii genomes from ten Genomic Groups (GGs) and various hosts was studied bioinformatically to determine if there was an association between their genomic characteristics, including the effector protein repertoire, and their isolation source. The differences in genome size, IS1111 count, number of coding sequences, accessory genome and others observed could be attributed to lineage-specific traits. Likewise, the GGs showed conserved sets of effector proteins, although intra-lineage variances were high in GGIV. Several effector proteins, e.g. Cem8 (CBU_1634a) and CBU_0469, were highly conserved, while CBU_2007 showed a remarkably high number of sequence variants. Conclusions C. burnetii exhibits genomic diversity that aligns with phylotypes rather than host species, suggesting that genomic traits as well as host factors influence disease outcome rather than a host species specific adaptation.

Different parasite challenge models have been used over many years in the development of novel vaccines against gastrointestinal nematodes of livestock. Typically, following vaccination with either native or recombinant proteins, the host animal is then given a bolus challenge of infective nematode larvae (iL3) or a trickle challenge where smaller numbers of iL3 are given at regular intervals over a period of time. The bolus method may be a robust test of whether high levels of vaccine-induced immunity translate to protection against a large pathogen insult, whereas the trickle infection method may be more appropriate to test the impacts of an exposure-induced anamnestic response. In the work presented here, three different models of testing gastrointestinal nematode vaccine efficacy were compared. Lambs (4-5months old) were vaccinated with the excretory/secretory products collected from ex-vivo Teladorsagia circumcincta fourth stage larvae (L4ESP) and then challenged with a bolus of 5,000 iL3 or with a trickle infection where 2,000 iL3 were administered 3 times per week for 4weeks (truncated trickle) or continuously challenged for 9weeks (trickle) until post-mortem. Monitoring of faecal egg counts following challenge demonstrated that there was no significant impact of vaccination on cumulative faecal egg count (cFEC) following bolus challenge but, during the period of regular ingestion of iL3 in both trickle challenge models, statistically-significant reductions in the cFEC [(40-46% reduction in mean cFEC (P<0.05); 68-71% reduction in median cFEC)] were observed. Shortly after cessation of the iL3 challenge in the truncated trickle challenge group, this protective effect of the vaccine on cFEC was lost whereas vaccine efficacy was maintained in the model with continued regular ingestion of iL3 (trickle challenge model, which most accurately reflect the parasite challenge in a field situation). In conclusion, the choice of challenge model had a profound impact on the ability to measure vaccine efficacy.

Equines are parasitized by complex communities of Strongylidae (Nematoda) comprising multi-species infections. Currently, Cyathostominae are most prevalent, while Strongylus species are only rarely detected. Since eggs and, in most cases, infective larvae cannot be differentiated to species level, except for Strongylus spp., species-specific knowledge of the pathology, epidemiology and ecology of these parasitic nematodes is limited. Reference sequence data for several cyathostomin species are limited or missing. Deep amplicon sequencing of internal transcribed spacer 2 (ITS-2) regions of nematodes has been used in equines previously, although barcoding studies demonstrated a better species resolution for the cytochrome c oxidase subunit I (COI) region. The present study introduces a nemabiome method based on sequencing of COI fragments. This method was applied to compare third stage larvae, representing strongyle communities, derived from regularly treated (RT) and never treated (NT) equine populations from Brazil, France (only RT), Germany, Ukraine, the UK, and the USA. Samples were predominantly from horses, but some were obtained from Przewalski's horses (Ukraine), donkeys (Germany, Ukraine) and kulans (Ukraine). Most sequence reads (87.7%) were identified to species level, but unclassified reads occurred more frequently in donkeys and kulans than horses. No obvious difference in species diversity and richness was observed between RT and NT equines. However, there were significant differences in species composition between the RT and NT groups. Strongylus spp. were more common in NT groups but also showed unexpectedly high abundances in RT horses. Cylicocyclus nassatus, Cylicostephanus longibursatus, and Cyathostomum catinatum were more abundant in RT groups, suggesting that strongyle communities in domestic equines may have been shaped by anthelmintic treatments during last decades. The decreased classification success for reads from non-caballine equines suggests that there are more strongyle species specific for this rarely-investigated group which requires additional efforts to improve the sequence database, particularly for these hosts.

Abstract Red seaweeds ( Rhodophyta ) and their polysaccharides represent promising, sustainable solutions for boosting aquaculture productivity. Rich in bioactive compounds such as carrageenan, agar, and sulfated galactans, these seaweeds have demonstrated the ability to improve growth, health, and disease resistance in various aquaculture species. This review examines the applications, benefits, and limitations of red seaweeds in aquaculture, with particular attention to their roles as feed binders, partial fishmeal replacements, feed supplements, and immunostimulants. Species such as Gracilaria , Kappaphycus , and Porphyra have been shown to enhance immune responses, promote gut health, and mitigate nutrient pollution in aquaculture systems. Despite these advantages, challenges remain, including high cultivation costs, variability in bioactivity, and supply chain constraints. This review highlights the growing potential of red seaweeds for sustainable aquaculture while identifying research needs related to dosage optimization, delivery strategies, and elucidating the molecular mechanisms of their effects. Supplementation with red seaweeds aligns with the United Nations’ Sustainable Development Goals, offering an eco-friendly alternative to antibiotics with the potential to yield both environmental and economic benefits in aquaculture.