Subventions et des contributions :

Subvention ou bourse octroyée s'appliquant à plus d'un exercice financier. (2017-2018 à 2020-2021)

High-yielding dairy cattle are susceptible to ketosis, a metabolic disease, which negatively affects the health, fertility and production of the cow. As a health trait, ketosis-resistance is difficult to improve genetically due to its polygenic nature, fuzzy phenotypes and unfavorable genetic correlation to milk production. The proposed project aims to clarify some of the uncertainty surrounding this trait and improve ketosis-resistance through genomics. Several thousand cows will be genotyped with a new, low-density chip, which contains markers that were identified in candidate genes for ketosis. The animals that will be genotyped already have 50K genotypes, which will allow for imputation of the new SNPs for any animal that has been genotyped with the 50K array. Imputing the genotypes of hundreds of thousands of animals will greatly improve the power to detect associations with ketosis phenotypes. Association analyses will be conducted for producer-recorded cases of clinical ketosis and displaced abomasum, measured milk beta-hydroxybutyrate, as well as deregressed estimated breeding values for each of these traits. These results will be validated in an independent population, as well by conducting functional studies of the most effective SNPs. This work will improve our understanding of ketosis, provide genomic tools to enhance resistance through selection and lead to targeted prevention and treatment strategies for cows identified as being susceptible to ketosis. x000D