By Krishani Sinhalage & Angela Cánovas, Center for Genetic Improvement of livestock, Department of Animal Biosciences, University of Guelph
Gastrointestinal nematode (GIN) infections remain one of the most significant parasitic challenges affecting the global sheep industry. Sheep become infected while grazing on pastures contaminated with nematode larvae, which invade the abomasum and small intestine. These infections compromise animal health and welfare and, in severe cases, can result in death. Even mild infections reduce feed efficiency and weight gain, resulting in poor production ultimately leading to substantial economic losses for producers.
Traditionally, GIN infections have been controlled using anthelmintic drugs combined with pasture management strategies. However, the growing problem of anthelmintic resistance among parasite populations has highlighted the need for sustainable control alternatives. One promising approach is selective breeding for GIN-resistant sheep, which offers a long-term, environmentally friendly solution.
Professor and OAC Reserach Chair Angela Cánovas (Center for Genetic Improvement of livestock, Department of Animal Biosciences, University of Guelph), is using advanced -OMICs technologies such as transcriptomics, metagenomics together with genomics to better understand the functional and molecular mechanisms underlying resistance and susceptibility to GIN infections in sheep. The Cánovas Lab aims to identify key functional candidate genes and regulatory elements, immune metabolic pathways, genetic markers, and estimate the genetic parameters of resistance-related traits to support informed breeding decisions.
Since 2015, the Cánovas Lab has been collaborating closely with Breezy Ridge Farm located in Georgina, Ontario, owned by Mr. and Mrs. Smith and sons, along with Delma Kennedy, Sheep Specialist at the Ontario Ministry of Agriculture, Food and Agribusiness (OMAFA). Each year, the research team collects fecal samples from yearling rams and ewes for phenotyping, along with ear tissue samples for genotyping. Additional data such as FAMACHA scores and body condition scores are also recorded.
Through annual breeding value estimations, the team provides the farmers with valuable insights into their flock’s genetic progress. According to Mr. and Mrs. Smith, their collaboration with the Cánovas Lab has led to remarkable results, approximately 92% of their flock now shows resistance to GIN infections, and lamb losses have decreased by nearly 50% compared to average rates in the Rideau Arcott breed.
This partnership demonstrates the powerful potential of combining cutting-edge genetic research with practical on-farm applications to improve animal health, productivity, and sustainability in the Canadian sheep industry.
