Divergent age-related changes in parasite infection occur independently of behaviour and demography in a wild ungulate.

As animals age, they exhibit a suite of phenotypic changes, often including reductions in movement and social behaviour ('behavioural ageing'). By altering an individual's exposure to parasites, behavioural ageing may influence infection status trajectories over the lifespan. However, these processes could be confounded by age-related changes in other phenotypic traits, or by selective disappearance of certain individuals owing to parasite-induced mortality.

Immune markers in goats selected for reduced gastrointestinal nematode egg count under artificial infection conditions.

This study aimed to further investigate the mechanisms responsible for inhibition of gastrointestinal nematode egg production in a line of Scottish Cashmere Goat selected for low faecal egg count. Animals were chosen as the lowest egg producers from a line selected for low egg output (selected group) with a second group from the wider herd based on high faecal egg count as controls. All animals were artificially infected with Teladorsagia circumcincta and Trichostrongylus vitrinus, then treated with anthelmintic and challenge infected prior to euthanasia and post mortem sampling.

Helminth parasites are associated with reduced survival probability in young red deer.

Helminths are common parasites of wild ungulates that can have substantial costs for growth, mortality and reproduction. Whilst these costs are relatively well documented for mature animals, knowledge of helminths' impacts on juveniles is more limited. Identifying these effects is important because young individuals are often heavily infected, and juvenile mortality is a key process regulating wild populations.

Faecal egg counts and immune markers in a line of Scottish Cashmere goats selected for resistance to gastrointestinal nematode parasite infection.

This study aimed to investigate the effect of selection for low faecal egg count (FEC) in Scottish Cashmere goats in comparison to a control line of unselected goats grazing the same pasture. Goats from generations F2 through to F9 were monitored for FEC, bodyweight, peripheral eosinophilia and IgG, IgA and IgE response against Teladorsagia circumcincta from the end of their first grazing season, through winter housing (during which a single artificial challenge dose of 10,000 drug susceptible T. circumcincta was given) and the following full grazing season.

Effect of anthelmintic treatment strategy on strongylid nematode species composition in grazing lambs in Scotland.

Background: Refugia based anthelmintic protocols aim to reduce the rate of development of anthelmintic resistance in gastrointestinal nematodes (GIN). Previous studies have illustrated the impact of different drenching regimes on drug efficacy and animal growth; however, the impact on nematode populations has yet to be characterised within natural infections. This study investigated the changes in species composition of GIN throughout the grazing season, following implementation of four different ivermectin drenching regimes over six years: neo-suppressive monthly treatment (NST), targeted selective treatment (TST), strategic prophylactic treatment (SPT) and treatment upon observation of clinical signs (MT).

Viability of the Happy Factor™ targeted selective treatment approach on several sheep farms in Scotland.

The aim of this study was to examine the use of Happy Factor™ weight based targeted selective treatment (TST) on several commercial farms in Scotland in combination with findings from a long term trial on a research farm to assess the potential for TST use in varying farming operations as an alternative to the current regimen of whole flock treatment. Lambs on each farm were regularly weighed and climatic conditions and pasture availability measured for inclusion into the Happy Factor™ model to calculate weight targets. Half of the lambs were allocated to TST treatment and any failing to reach the weight target was treated with the anthelmintic of choice on that farm, while the remaining half of each flock was treated with anthelmintic as per normal practice on that farm (routine treatment, RT).

A comparative study of the effects of four treatment regimes on ivermectin efficacy, body weight and pasture contamination in lambs naturally infected with gastrointestinal nematodes in Scotland.

Refugia-based drenching regimes have been widely recommended to slow development of anthelmintic resistance but there are few comparisons between different treatment approaches in the UK. The impact of four ivermectin treatment regimes on drug efficacy, lamb body weight and nematode contamination during a 154 day grazing season were evaluated in a consecutive five year field study. Regimes were whole-flock treatment every 4 weeks (NST), targeted selective treatment (TST) based on individual performance, strategic whole-flock treatments at pre-determined times (SPT) or whole-flock treatment when clinical signs were apparent (MT).