Investigating kinetics and biology of mucosal immunity to gastrointestinal nematodes in sheep

Lead Applicant: Emma Borkowski

Research Priority: Animal Health & Welfare

Program Type: Tier 1

Funding Cycle: 2024/2025

Research Centre: Ontario Sheep Research Centre - Ponsonby

Research Summary: Gastrointestinal nematodes (GINs) are a major threat to sheep health. Dewormer resistance is ubiquitous and genetic selection of sheep for mucosal immunity, particularly antibody to carbohydrate larval antigen (CarLA), offers sustainable mitigation. However, kinetics of CarLA antibody and the influence of host factors on this response remain uncharacterized in the Canadian context. In year 1, this project will isolate Ontario-sourced GINs for use in controlled challenge trials. Naive lambs of differing age (year 2) and sex (year 3) will be administered GINs biweekly for 5 months, followed by a 4-month interruption, then 3 months of resumed exposure to simulate a Canadian grazing season, winter, and spring. GIN parasitism and CarLA antibody will be monitored weekly to describe temporal changes and age/sex effects. Results will be incorporated into genetic selection programs to improve sheep health and support further research to identify management strategies that improve mucosal GIN immunity in Canadian sheep.