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ARS Home » Southeast Area » Booneville, Arkansas » Dale Bumpers Small Farms Research Center » Research » Publications at this Location » Publication #368919
Research Project: Sustainable Small Farm and Organic Grass and Forage Production Systems for Livestock and Agroforestry

Location: Dale Bumpers Small Farms Research Center

Title: Integrating genetic selection with selective anthelmintic treatment to manage gastrointestinal nematodes in Katahdin sheep in the United States

Author
item Burke, Joan
item NOTTER, DAVID - Virginia Tech
item MORGAN, JAMES - Katahdin Hair Sheep International
item MILLER, JAMES - Louisiana State University
item LEWIS, RON - University Of Nebraska
item HEIDARITABAR, MARZIEH - University Of Alberta

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 6/28/2019
Publication Date: 8/27/2019
Citation: Burke, J.M., Notter, D.R., Morgan, J.L., Miller, J.E., Lewis, R.M., Heidaritabar, M. 2019. Integrating genetic selection with selective anthelmintic treatment to manage gastrointestinal nematodes in Katahdin sheep in the United States. COMBAR/ACSRPC Joint meeting. 74. https://docs.wixstatic.com/ugd/6ef604_95942af75e954c5680999df431ff4c32.pdf

Interpretive Summary:

Technical Abstract: Gastrointestinal nematodes (GIN) continue to plague the small ruminant industry throughout the world due to the prevalence of anthelmintic resistance. Producers are encouraged to utilize tools to manage GIN, which include selective deworming based on FAMACHA to slow resistance and genetic selection of individuals within a flock/herd. The National Sheep Improvement Program (NSIP; USA) collaborates with Sheep Genetics (MLA, Australia) to provide estimated breeding values (EBV) for parasite resistance based on fecal egg counts (FEC) collected at weaning (42-90 days of age) and post-weaning (91-150 days of age) for sheep and goat breeds in the USA. The Katahdin breed is a composite hair sheep with variable levels of genetic resistance to GIN. We have been working with Katahdin producers (21 farms; 2009-2013 and 2017-2019) enrolled in NSIP to collect phenotypic data (body weights, maternal traits, FEC and FAMACHA scores, and incidence of deworming to post-weaning measures). The objective is to better understand consequences of selection for GIN resistance or resilience. In this presentation, we will summarize relationships between FEC EBVs, FAMACHA scores and incidence of deworming to post-weaning (9.6% of 2,613 lambs) and results of a high-density genome scan of progeny-tested Katahdin sires to demonstrate the value of having genetic resistance within flocks. Parasite resistant lambs with balanced EBVs become valuable replacement sheep within seedstock and commercial operations. [This project was supported by USDA National Institute of Food and Agriculture, Organic Agriculture Research and Extension Initiative grant (#2016-51300-25723) and Southern Sustainable Agriculture Research and Education (#OS19-124).