Comparing the genetic architecture of energy balance predicted by mid-infrared spectrometry, a novel energy deficiency score, and several biomarkers

ABSTRACT: Negative energy balance (NEB) during early lactation is a critical physiological challenge in high-producing dairy cows, affecting both their health and production performance. The objectives of this study were: (1) to compare the genetic architecture of logit-transformed predicted NEB (LPNEB), a logit-transformed novel energy deficiency score (LEDS), 15 biomarkers, and 3 production traits using SNP-based genomic correlation analysis; (2) to extend this study to a chromosomal level to identify specific genomic regions involved in the regulation of energy metabolism; and (3) to compare the independent contributions of 8 traits to the underlying genetic architecture of LPNEB and LEDS. The SNP effects estimated from single-trait models can be used to quickly calculate genomic correlations for 20 traits. The results indicate strong genomic correlations between LPNEB and LEDS, as well as with key metabolic biomarkers, particularly blood nonesterified fatty acids (NEFA), highlighting their importance in energy metabolism. Furthermore, NEFA was a strong independent contributor to both LPNEB and LEDS. Chromosome regions located on BTA19 and BTA25 were identified as potentially associated with NEB. By combining genomic correlation and contribution analyses, this study provides valuable insights into the genetic basis of NEB and related traits in dairy cows.