Immunkompetenz gegenüber gastrointestinalen Nematoden und deren züchterische Bearbeitung beim Schaf – 2. Selektionsmerkmale und Herausforderungen für die Zucht.

Infections with gastrointestinal nematodes on pasture have negative impact on animal health and production. Anthelmintics are used for deworming to prevent an excessive increase in parasite load and to treat parasitosis. Due to the progressive resistance of gastrointestinal nematodes to anthelmintics, their effectiveness is increasingly reduced. For this reason, alternatives are needed to combat infections with gastrointestinal nematodes. A sustainable strategy with great potential is the breeding of sheep with increased immunocompetence against gastrointestinal nematodes. Various indicators of gastrointestinal nematode infection can and should be used as selection traits for this purpose. Given the multifactorial background of infection events, the interpretation of the data and the definition of adequate breeding goals are particularly challenging. This review article deals with established and putative selection traits for breeding sheep with improved immunocompetence regarding gastrointestinal nematodes. With reference to the current state of sheep breeding in Germany, the challenges, especially with regard to the definition of breeding goals and phenotyping, are identified. The article ends with suggestions for possible first and further steps for German sheep breeding. [ABSTRACT FROM AUTHOR]