OSC Activity I.1
Over-wintering of gastrointestinal parasites in organic sheep production
Activity Researchers
Name | Affiliation |
---|---|
Andrew Peregrine, Lead Researcher aperegri@ovc.uoguelph.ca |
Associate Professor |
Paula Menzies, Collaborator pmenzies@ovc.uoguelph.ca |
Associate Professor |
Jocelyn Jansen, Collaborator jocelyn.jansen@ontario.ca |
OMAFRA Elora Resource Centre Unit 10 6484 Wellington Rd 7 Elora ON N0B 1S0 |
John vanLeeuwan, Collaborator | Professor Epidemiology & Ruminant Health Management University of Prince Edward Island Atlantic Veterinary College |
Andria Jones, Collaborator aqjones@uoguelph.ca |
Assistant Professor Population Medicine Ontario Veterinary College University of Guelph 50 Stone Road Guelph, ON N1G 2W1 |
Laura Falzon, Collaborator |
Graduate Student Ontario Veterinary College University of Guelph 50 Stone Road Guelph, ON N1G 2W1 |
Objectives
To determine:
- Factors affecting over-wintering and periparturient egg rise (PPER) in ewes:
- Group level factors e.g. season of lambing.
- Individual level factors e.g. prolificacy.
- If strategic timing of anthelmintic treatment reduces PPER.
- Factors affecting the over-wintering survival of GIN including Haemonchus contortus on pasture under central Canadian conditions.
- If over-wintered L3 H. contortus larvae are capable of establishing a patent infection in naïve lambs.
Activity Summary
This project will improve understanding of factors that affect two major sources of gastrointestinal nematodes (GIN) responsible for parasitic infections in sheep: over-wintering of hypobiotic larvae in adult ewes and the subsequent periparturient egg rise (PPER) which then contaminates spring pasture resulting in infection of naïve lambs; and over-wintering of infective L3 larvae on pasture from contamination from the previous grazing season. The first – over-wintering in ewes - will be done by examining PPER levels in ewes under different management systems, specifically out-of-season lambing, how individual animal factors influence PPER levels, and the impact of strategic and limited use of anthelmintics in reducing this rise. The effect of winter climate on survival of infective GIN larvae, including Haemonchus contortus, on pastures will be done by examination of presence of larvae on contaminated pasture plots. One acre plots of pasture grazed that season by infected sheep will be assessed from the fall after animal removal until the spring before turn-out. Micro-climate data will be collected using time-temperature-humidity recorders at ground and human height. Presence and type of GIN larvae will be assessed by larval pasture sampling when not covered by snow. Infectivity of present larvae will be assessed by spring grazing of naïve tracer lambs. This information will be used to develop a strategic integrated parasite control program for both organic and conventional sheep flocks in central Canada which will reduce level of disease, reliance on anthelmintics, and thus improve the productivity of this sector.
Results
- Extension Program Promotes Healthy Sheep and Goats
- University of Guelph. 2012
- Handbook for the Control of Internal Parasites of Sheep [PDF - 5.5 MB]
- A longitudinal study on the effect of lambing season on the periparturient egg rise in Ontario sheep flocks
- Preventative Veterinary Medicine (2013) 110: 467-480
- Managing Internal Parasites in Sheep [PDF - 328 kB]
- The Canadian Organic Grower. 2012
- Managing Parsites in Ontario Sheep Flocks
- Organic Science Cluster Success Story. 2012
- Organic Science Cluster Success Story. 2012
- Parasite Control on Organic Sheep Farms in Ontario [PDF - 2.6 MB]
- Review: Genetics of helminth resistance in sheep
- Canadian Journal of Animal Science (2014) 94: 1-9
- Sheep solutions: An interview with Dr. Andrew Peregrine
- OACC News Article. 2013
- A systematic review and meta-analysis of factors associated with anthelmintic resistance in sheep
- Preventative Veterinary Medicine (2014) 117: 388-402
- Video: Fecal Sampling for gastrointestinal nematodes in sheep
- University of Guelph. 2012
Background and Supporting Documents
- Anhydrobiosis increases survival of trichostrongyle nematodes
- Journal of Parasitology (2006) 92: 1002-1009
- The epidemiology of abomasal nematodes of sheep in Sweden, with particular reference to over-winter survival strategies
- Veterinary Parasitology (2004) 122: 207-220
- Influence of periparturient nutritional demand on resistance to parasites in livestock
- Parasite Immunology (2008) 30: 113-121
- The peri-parturient rise in sheep. Faecal worm egg counts in normal and late lambing ewes
- The Veterinary Quarterly (1987) 9: 97-102
- Seasonal changes of gastrointestinal nematode burden in sheep under an intensive grazing system
- Veterinary Parasitology (2003) 118: 79-92
Partners and Sponsors
- Agriculture and Agri-Food Canada
- Ontario Sheep Marketing Agency
- University of Guelph, Gartshore Memorial Sheep Fund
- Canadian Sheep Breeders' Association