Genome-Wide Association Study between Single Nucleotide Polymorphisms and Flight Speed in Nellore Cattle

Area of Science:

• Animal Genetics
• Genomics
• Behavioral Science

Background:

• Cattle temperament is crucial for beef cattle profitability, influencing productivity, animal welfare, and safety.
• Temperament is a complex trait influenced by genetics and environment.
• Understanding the genetic basis of temperament is essential for selective breeding.

Purpose of the Study:

• To conduct a genome-wide association study (GWAS) to identify genomic regions associated with cattle temperament.
• To detect potential candidate genes and their biological mechanisms influencing temperament, measured by flight speed (FS).
• To enhance comprehension of the genetic control of temperament in Nellore cattle.

Main Methods:

• A single-step genome-wide association study (ssGBLUP) was employed, integrating phenotypes from genotyped and non-genotyped animals.
• Utilized a high-density Bovine SNP BeadChip with 777,962 markers, reduced to 455,374 after quality control.
• Combined extensive pedigree data (162,645 animals) with genotypic data from 1,384 animals.

Main Results:

• Identified nine significant genomic regions (SNP windows) associated with flight speed (FS) across eight bovine chromosomes.
• Estimated heritability for FS was 0.21 ± 0.02.
• Six candidate genes (NCKAP5, PARK2, ANTXR1, GUCY1A2, CPE, DOCK1) were identified within these regions, with several linked to neurological functions.

Conclusions:

• The study successfully identified nine genomic regions and six candidate genes associated with beef cattle temperament (FS).
• These findings provide valuable insights into the genetic architecture of temperament in Nellore cattle.
• The identified genes and regions can aid in developing strategies for genetic improvement of cattle temperament.