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Full-Text Articles in Animal Sciences
Genotype By Environment Interaction And Heteroscedasticity Influence The Expression Of Parasite Resistance In Katahdin Sheep, Brian C. Arisman, Joan M. Burke, James L. M. Morgan, Ronald M. Lewis
Genotype By Environment Interaction And Heteroscedasticity Influence The Expression Of Parasite Resistance In Katahdin Sheep, Brian C. Arisman, Joan M. Burke, James L. M. Morgan, Ronald M. Lewis
Department of Animal Science: Faculty Publications
Increasingly, sheep producers are choosing breeds that express resistance to gastrointestinal parasites due to reduced efficacy of anthelminthic drugs. One such breed is Katahdin. Katahdins are raised in various climates and management systems in the United States, which can be combined into eco-management clusters to describe production environments more holistically. The objectives of this study were to determine if genotype by environment interaction (G × E) and heteroscedasticity existed across these eco-management clusters for traits indicative of parasite resistance. Body weights (BW), FAMACHA scores (FAM), and fecal egg counts (FEC) were collected at around 90 d in 3,527 Katahdin lambs …
Clustering Climate And Management Practices To Define Environmental Challenges Affecting Gastrointestinal Parasitism In Katahdin Sheep, Brian C. Arisman, Joan M. Burke, James L. M. Morgan, Ronald M. Lewis
Clustering Climate And Management Practices To Define Environmental Challenges Affecting Gastrointestinal Parasitism In Katahdin Sheep, Brian C. Arisman, Joan M. Burke, James L. M. Morgan, Ronald M. Lewis
Department of Animal Science: Faculty Publications
Gastrointestinal nematodes (GIN) negatively affect the performance and well-being of sheep. Due to anthelmintic resistance, GIN are difficult to control leading producers to choose breeds that can exhibit resistance to parasitism. An example is Katahdin sheep. Katahdins are raised in various climates and management systems in the United States. These environmental factors can be combined to form eco-management groupings or clusters. We hypothesized that GIN challenge varies predictably based on the characteristics of these environmental clusters. Forty Katahdin producers from across the United States were surveyed for management information, with body weights (BW), fecal egg counts (FEC), and FAMACHA scores …