Gastrointestinal nematodes (GIN) infect goats grazing contaminated pastures causing disease and economic loss. Dewormers are a last resort in organic production and efficacy is declining as parasites build resistance. Dr. Emma Borkowski is investigating the potential of identifying animals capable of mounting a superior immune response to these nematodes by screening for GIN antibody in goat saliva. If successful, this approach could improve herd health and grazing potential through selection of animals carrying immunological GIN resistance.
Research Objectives
- Evaluate whether goats grazed under Ontario conditions develop a detectable salivary immunoglobulin A (IgA) response to carbohydrate larval antigen (CarLA)
- Analyse whether salivary CarLA IgA is associated with reduced gastrointestinal nematode parasitism in goats under Ontario grazing conditions
- Evaluate the optimal age at which to perform the CarLA Saliva Test in Ontario goats to facilitate genetic selection for nematode immunity
Related Resources
Progress and Results
Research Update (March 2026)
KEY TAKEAWAYS (PRELIMINARY OBSERVATIONS)
- The CarLA Saliva Test is able to detect variation in antibody levels in Ontario goats and there is good potential for the test to be offered commercially to goats as well as sheep.
- The target age groups for testing should be kids in their first year of life or yearlings in their second.
- Further research is required to better understand the relationship between antibody levels and parasitism in goats. Can antibody levels predict future parasite levels?
- Farm management practices linked to lower parasite exposure — such as raising other livestock species or closely monitoring goats for signs of parasites — were associated with lower antibody levels while practices linked to higher parasite pressure, such as frequent dewormer use (oral drench), were associated with higher antibody levels. More research is needed to fully understand these relationships and how they may impact interpretation of CarLA Saliva Test results.
Research Update (March 2025)
KEY TAKEAWAYS (PRELIMINARY OBSERVATIONS)
- Patterns in nematode burdens and species were similar to those reported from Ontario sheep.
- Detectable levels of anti-CarLA IgA were found in saliva of goats of all age groups, though the prevalence of detectable antibody increased with age.
- Although analysis of the relationship between salivary IgA and nematode burdens in the study goats is ongoing, preliminary findings suggest that yearlings may be the most appropriate target for possible genetic selection based on CarLA antibody.
- Researchers continue to analyze samples to assess the relationships between serum and salivary antibody and other factors that may influence salivary antibodies in goats.
Additional Links and Resources
Article (Aug 2024) Student goat immunity project will help farmers breed healthier herds.
Newsletter (Spring 2024) Canadian National Goat Federation newsletter article (pages 15-16): Investigating Nematode Immunity in Ontario Goats
Background Information
From the research activity proposal:
Gastrointestinal nematodes (GINs) infect goats grazing contaminated pastures and are ubiquitous worldwide. GINs are an important cause of disease and economic loss, and control has traditionally relied on synthetic dewormers. However, dewormers are a last resort in organic goat production, and their efficacy is progressively being limited by increasing parasite resistance. GIN control poses such a problem in the Canadian goat industry that many goats are raised indoors, and pasture resources are underutilized.
A sustainable method of GIN control that has been investigated in sheep involves leveraging the host’s immune response to parasites. Recently, screening the saliva of sheep for antibodies to GINs was found to be a promising measure of parasite immunity in an Ontario sheep flock. Research in New Zealand also indicates salivary antibody is heritable, allowing the use of genetic selection to reduce pasture contamination with GINs and enable safer grazing. Wider-scale investigation of saliva testing for GIN immunity in Canadian sheep is currently underway.
In comparison, saliva screening for GIN immunity has not been intensively investigated in goats. Preliminary data from New Zealand suggests that goats develop GIN immunity at a later age than sheep, but whether goats develop detectable GIN antibody levels under Canadian grazing conditions, and the optimal age to screen, are not known.
This project will evaluate GIN antibody levels in goats grazed in Canada. Thirty goat farms located across Ontario, the largest goat-producing province, will be recruited to participate. Producers will randomly select 10 does in each of three age categories to enrol in the study: <1 year old, yearling, and 2+ year old. Kits will be provided for submission of fecal samples from enrolled animals to the University of Guelph monthly between May and September. Samples will be used to monitor GIN parasitism via fecal egg counting. In October, researchers will visit each farm to collect saliva and feces from enrolled goats to assess GIN antibody levels and parasitism, respectively.
The results will help determine if salivary GIN antibody screening could be an effective measure of GIN immunity in Canadian goats, and at what age this screening should be performed. The results will contribute to improving goat health on organic and conventional farms and has the potential to improve efficiency of goat production by increasing use of pasture resources.
Contributing Partners
Meet the Research Team
Dr. Emma Borkowski
Dr. Emma Borkowski is an Assistant Professor at the Ontario Veterinary College (OVC) Department of Pathobiology, University of Guelph. Dr. Borkowski studies veterinary parasitology, particularly parasites of livestock, immune responses to parasites, and sustainable parasite control. She is passionate about improving current understanding of how livestock and their internal parasites interact, with a goal of developing parasite prevention and control methods.
Activity 17 Research Team
Name | Affiliation |
|---|---|
Dr. Andrew Peregrine | University of Guelph |
Dr. Cathy Bauman | University of Guelph |
Dr. John Gilleard | University of Calgary |
Dr. Paula Menzies | University of Guelph |
We asked Dr. Borkowski
What got you interested in this research project?
I’ve been working with the small ruminant industry for several years now, and there is so much potential that is being held back by nematode parasites. Sheep and goat farmers need help finding sustainable ways to control parasites, and breeding animals with better immune responses is an important tool. I want to help farmers develop that tool so they can reach their full potential.
Where is your research taking place?
My work aims to bridge the farm and the lab, so we are working with multiple goat farms from across Ontario. Throughout the summer our farms send us samples to process in out lab at the University of Guelph. Each fall we visit the farms to check up on each study goat and share our findings with the farmers.
What drew you to organic agriculture research?
Since my research focuses on sustainable parasite control, I’ve always been involved in work supporting organic agricultural principles. Now that treatment resistance is widespread in sheep and goat parasites, the industry (both organic and conventional) needs researchers to develop and refine sustainable control methods. Working with organic producers already experienced with sustainable parasite control options helps other sheep and goat producers see the benefits of these approaches, and more importantly, how they might fit in on their farms.
How are you encouraging or training the next generation of scientists?
Mentoring new animal health scientists is very important to me, so I endeavour to support as many trainees as I can. My doctoral student, Dr. Caitlin Evered, never contemplated goats as a species of interest before joining this project, and now they are one of her favourite species! I also constantly host undergraduate research students, many of whom have little to no prior research experience. It’s a great way to expose them to the diverse career options available in agricultural sciences.
Outside of your research pursuits, what is an activity you enjoy doing in your free time?
When the weather permits, I love spending time outside puttering around my vegetable and perennial flower gardens. In less clement seasons I enjoy making various crafts. I also semi-intentionally breed Lake Malawi cichlids (semi-intentional in that I keep both males and females and am constantly snowed under by the number of fry they produce).
