Genome scan for meat quality traits in Nelore beef cattle

Area of Science:

• Animal Genetics
• Food Science
• Quantitative Genetics

Background:

• Meat quality traits significantly impact consumer acceptance and beef demand.
• Evaluating meat tenderness is costly and damages carcasses, limiting traditional selection methods.
• Genetic improvement for meat quality is crucial for the beef industry.

Purpose of the Study:

• To identify quantitative trait loci (QTL) associated with key meat quality traits in Nelore cattle.
• To understand the genetic architecture controlling traits like Warner-Bratzler shear force, color, and water-holding capacity.
• To explore potential differences in genetic control compared to taurine cattle.

Main Methods:

• Genome-wide association studies (GWAS) were performed using Illumina BovineHD BeadChip genotype data.
• Phenotypic data for meat tenderness, fat, muscle area, color, water-holding capacity, cooking loss (CL), and pH were collected.
• Analysis focused on identifying QTL across 536 Nelore cattle.

Main Results:

• Most meat quality traits in Nelore cattle are controlled by numerous QTL with small effects.
• A few large-effect QTL were identified for fat redness (a*), cooking loss (CL), and muscle pH.
• The identified QTL regions and gene pathways differ from those found in taurine cattle.

Conclusions:

• Genetic control of meat quality in Nelore cattle involves many small-effect QTL and some large-effect QTL.
• Genomic regions and pathways associated with meat quality traits in Nelore cattle are distinct from taurine breeds.
• These findings will inform future QTL mapping and the development of genomic selection models for Nelore beef quality.