ASGGN Country Representative


Tad Sonstegard       

Tad's research focuses on development of genomic tools to characterize the structure and function of the bovine genome, and the application of these tools using novel statistical methodology to improve and accelerate genetic improvement of cattle for traits of economic importance. As an outcome, tools and knowledge will be delivered to industry partners that facilitate genome-wide selection for immediate application to genetic improvement. These efforts will be magnified by impact on the genome assemblies of other ruminant species; where the importance of water buffalo, sheep, and goats in providing economic security in underdeveloped countries cannot be overstated.



Development and Application of Technologies for Genetic Improvement in Ruminants, Molecular Biology, Genomics

GRA livestock Research Group Country Contact

Organisation:            USDA

Richard Hegg          

Nancy Cavallaro      

US Beef Feed Efficiency

National Program for Genetic Improvement of Feed Efficiency in Beef Cattle

The National Program for Genetic Improvement of Feed Efficiency in Beef Cattle is a multiyear USDA funded project to develop selection tools and better understanding of feed efficiency in beef production. Because feed intake is a technologically challenging and expensive trait to record on large numbers of animals we expect most of the selection for increased feed efficiency to occur through selection on genetic marker information. Our goal is to identify the genetic markers associated across multiple breeds with feed intake in the beef production system.

This project will utilize genomic DNA tests in combination with feed intake and end product quality information from 8,000 animals representing 8 breeds:
Red Angus

Beyond developing genetic marker tests for use in multiple breeds of cattle, we will also conduct research to help us better understand feed efficiency:

  • Gene expression analysis of various tissues in animals with differences in feed efficiency.
  • Determine microbial population variation associated differences in feed efficiency.
  • Evaluate mitochondrial (cell power houses) differences in animals with differences in feed efficiency.
  • Conduct digestibility trials using animals with differences in feed efficiency.
  • Evaluate forage vs. concentrate level impacts on observed feed efficiency during different production phases (backgrounding and finishing) and also consistency of genetic marker tests across diets.
  • Engage undergraduate students in the research of feed efficiency in beef cattle.

We are also working with selected seed stock producers in multiple breeds to help them understand genetic marker technology and how to utilize it within their selection goals. As marker tests become available for feed intake in their breeds we will work with this group of producers to incorporate selection for feed intake as part of their multiple trait selection strategy.


Dan Loy
Professor of Animal Science
Extension Beef Specialist
Director, Iowa Beef Center

Iowa State University
313 Kildee Hall
Ames, IA 50011

Phone: 515-294-1058
Fax: 515-294-3795

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