Genomic selection in United States dairy cattle

Area of Science:

• Animal Genetics
• Quantitative Genetics
• Dairy Science

Background:

• The U.S. dairy cattle genomic selection program has significantly accelerated genetic gain.
• The rate of genetic gain has doubled since 2010, with average annual net merit increases of $85.
• The number of available genotypes has rapidly increased, exceeding 6.5 million by 2022.

Purpose of the Study:

• To summarize the advancements and impact of the U.S. dairy cattle genomic selection program.
• To highlight the expansion of evaluated traits and the incorporation of new methodologies.
• To underscore the collaborative efforts driving progress in dairy cattle breeding.

Main Methods:

• Utilizing genomic data from millions of dairy cattle for genetic evaluations.
• Expanding evaluations to over 50 traits, including feed efficiency, livability, and health.
• Implementing haplotype matching for pedigree augmentation and recessive condition discovery.
• Developing blended evaluations for crossbred animals based on breed composition.

Main Results:

• Doubled the rate of genetic gain in U.S. dairy cattle, with average annual net merit increasing from $40 to $85.
• Expanded evaluations to include new traits like feed efficiency and various health indicators.
• Successfully extended evaluations to crossbred animals using a blended approach.
• Identified causative variants for 27 recessive conditions, improving accuracy through gene testing and genotyping.

Conclusions:

• The genomic selection program has dramatically improved genetic gain and economic value in dairy cattle.
• Continued advancements in genomic technologies and trait evaluation are crucial for future breeding success.
• Close collaboration between industry and research is essential for the program's ongoing effectiveness.