|LOZADA-SOTO, EMMANUEL - North Carolina State University|
|TIEZZA, FRANCESCO - University Of Florence|
|COLE, JOHN - Former ARS Employee|
|MALTECCA, CHRISTIAN - North Carolina State University|
Submitted to: World Congress of Genetics Applied in Livestock Production
Publication Type: Proceedings
Publication Acceptance Date: 2/18/2022
Publication Date: 7/7/2022
Citation: Lozada-Soto, E.A., Tiezza, F., Cole, J.B., Van Raden, P.M., Maltecca, C. 2022. Patterns of inbreeding and selection using runs of homozygosity in North American dairy cattle. World Congress of Genetics Applied in Livestock Production. Front Matter, Commun. 188, pp. 806-809. https://doi.org/10.3920/978-90-8686-940-4_188.
Technical Abstract: The main objective of this study was to leverage genomic information to ascertain patterns of inbreeding and selection in five North American dairy cattle populations. We obtained genotypes for over 4 million individuals of the Ayrshire, Brown Swiss, Guernsey, Holstein, and Jersey breeds. Inbreeding based on runs of homozygosity was calculated in each population. The average inbreeding ranged from 0.11 for Ayrshire to 0.17 for Jersey. We calculated a coefficient of homozygosity for each marker. Highly homozygous markers were joined into larger genomic segments of interest that ranged from 0.08 to 7.83 Mb in length and spanned 14 chromosomes across breeds. Annotation of genes and QTLs in the highly homozygous regions revealed selection for economically important traits, notably for udder and cow health, productive life, and reproductive traits. We found differences across breeds on inbreeding load, genomic regions of high inbreeding, and selection signatures.