GENOME-WIDE ASSOCIATION STUDY FOR GROWTH TRAITS IN BLANCO OREJINERO (BON) CATTLE FROM COLOMBIA.

• High additive genetic variance explained by markers were detected in birth weight and daily weight gain at weaning • Regions associated with growth and development processes and reported QTLs were identified • Two common BTA regions shared by most growth traits increase the possibility of QTL presence in these chromosomes. • Growth-related trait analysis allows detecting reliable specific-region markers and pleiotropic effects In the Colombian Creole cattle breed Blanco Orejinegro (BON), the mechanisms involved in growth trait variation are not well characterized. The aim of this work was to identify genomic regions associated with growth traits variability of Colombian BON cattle. The analyzed information included 439 individuals belonging to 14 herds with genotypes for 107,999 SNPs and genealogical and phenotypic information of deregressed genetic values of BON animals for the following growth traits: birth weight (BW), weaning weight (WW), yearling weight (YW), daily weight gain between birth and weaning (DWG), time to reach 120 kg of live weight (T120), and time to reach 60% of adult weight (T60%). A genome-wide association analysis (GWAS) was performed using the Bayes Cπ method. The association tests showed different signals with effect on the phenotypic variation of growth traits in Colombian BON cattle located within genomic regions with genes and metabolic pathways of crucial biological processes related to growth and development, and associated with at least one QTL previously reported, especially in Bos taurus autosome (BTA)1, BTA2, BTA6, BTA10, and BTA20. Two regions with effect on several growth traits were identified; the first in BTA1 with effect on WW, YW, T120, and T60%, and the second in BTA3 with effect on BW, WW, DWG, and T120, showing a genetic correlation between growth traits. These results will improve our biological and genetic understanding of growth traits in Colombian BON cattle. [ABSTRACT FROM AUTHOR]