Genomic evaluation for wellness traits in US Jersey cattle

Area of Science:

• Animal Genetics and Breeding
• Dairy Cattle Health Management
• Genomic Prediction Models

Background:

• Increasing Jersey cow populations in the U.S. necessitate improved health management strategies.
• Producer-recorded data is crucial for developing accurate genomic predictions for dairy cattle wellness.
• Health disorders pose significant risks to dairy cow and calf well-being and farm productivity.

Purpose of the Study:

• To develop and evaluate genomic predictions for various cow and calf wellness traits in Jersey cattle.
• To assess the feasibility and reliability of using a genomic threshold model for health trait evaluation.
• To provide tools for producers to mitigate health disorder risks in their Jersey herds.

Main Methods:

• Utilized producer-recorded phenotypic data, pedigree, and genotypes from 41,271 Jersey animals.
• Analyzed traits including mastitis, metritis, retained placenta, displaced abomasum, ketosis, lameness, milk fever, respiratory disease, scours, and calf livability.
• Employed a univariate threshold animal model and single-step genomic BLUP for analysis, with imputation for low-density genotypes.

Main Results:

• Heritability estimates for wellness traits ranged from 0.061 (displaced abomasum) to 0.120 (lameness).
• Genomic predicted transmitting abilities showed average reliabilities between 32% (displaced abomasum) and 51% (mastitis, calf livability).
• The genomic threshold model proved feasible for evaluating cow and calf wellness traits.

Conclusions:

• Direct genomic evaluation of cow and calf wellness traits in Jersey cattle is achievable.
• The developed genomic predictions offer moderate reliabilities, comparable to other lowly heritable traits.
• These genomic tools can assist Jersey producers in proactively managing and reducing health disorder risks.