# Exploring the Genetic Basis of Ketosis: Preliminary GWAS Findings on Beta-Hydroxybutyrate Levels in Holstein Cattle

## TL;DR

This study identifies genetic regions in Holstein cattle linked to ketosis, a metabolic condition affecting dairy cows, using blood measurements of a key ketone body.

## Contribution

The study reports preliminary GWAS findings of SNPs on Chromosome 15 and 5 associated with beta-hydroxybutyrate levels in pre-calving Holstein cows.

## Key findings

- Five significant SNPs on Chromosome 15 and one on Chromosome 5 were associated with beta-hydroxybutyrate levels.
- The SNPs on Chromosome 15 are in a region with genes related to lipid metabolism and energy balance.
- The findings suggest a genetic basis for ketosis susceptibility in Holstein cattle.

## Abstract

Ketosis is a metabolic condition characterized by a shift in energy metabolism, occurring when glucose availability is depleted and fat becomes the alternative primary energy source, resulting in the accumulation of ketone bodies. In dairy cattle, ketosis represents a significant challenge, adversely affecting both animal health and farm productivity. The genetic basis of ketosis in cattle has attracted increasing attention, with genome-wide association studies (GWAS) emerging as a crucial method for identifying relevant genetic factors. This study was aimed at investigating genome-wide regions associated with beta-hydroxybutyrate (BHB) concentrations in Holstein–Friesian cows' blood before calving in the United Kingdom. BHB measurement data from 253 previously genotyped cows were used in the analyses. The results revealed five significant SNPs on Chromosome 15 (BTA15) and one significant SNP on BTA5 (p < 1.60e − 6). Notably, the SNPs on BTA15 clustered within a genomic region enriched with genes implicated in lipid metabolism and energy balance, highlighting its potential role in ketosis susceptibility. These preliminary findings refine the genetic architecture of ketosis and offer new avenues for improving dairy cattle health and welfare through targeted genetic selection programs while highlighting the need for validation in larger and independent populations.