Does Cattle Breed Performance Vary Across Production Systems?

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Written By: Alexa Johnson and Mark Boggess

 

Scientists at the United States Meat Animal Research Center (USMARC), Clay Center, NE, are working to help producers better understand the relationships between beef genetics, local production environments, and local management systems, so they can remain profitable while consistently producing high quality beef.

To meet this goal, Dr. Larry Kuehn, and USDA Agricultural Research Service colleagues at Clay Center, NE, Fort Keogh, MT, Fort Collins, CO, Woodward, OK, and El Reno, OK, are exploring the diverse environmental factors affecting feeder cattle performance across environments and management systems. In a 4-year project initiated in 2019, Dr. Kuehn and colleagues are looking at the relationships and interactions between animal genetics, local production environments, and diverse management systems used to feed and manage the cattle. This project is known as the Beef Grand Challenge (BGC) project.

With approximately 500 head of cattle evaluated annually in this 4-year project and comprehensive data and genetic information being collected, this research promises to provide valuable information to improve producer profitability and sustainability across diverse environments and management strategies.  This project provides an opportunity to determine which breeds are most advantageous under variable management and environmental conditions.

For the BGC, researchers are using a USMARC cow herd known as the Germplasm Evaluation herd. This 4,000 head cow herd mirrors the genetic merit and genetic variation that exists in the larger North American cow herd and includes genetic contributions from the 18 most popular cattle breeds in North America.

Calves are born in the spring and fall and are weaned at USMARC. Spring-born calves are weighed and sorted by genetic makeup into three uniform groups of 120 head. One group is shipped to the Fort Keogh Livestock and Range Research Laboratory near Miles City, MT, where they are managed in a long yearling management program on native rangelands. A second group is shipped to the Grazinglands Research Laboratory near El Reno, OK, where they are also managed in a long yearling program, but are wintered on wheat pastures. The third group stays at USMARC and goes into the feedlot. All cattle are fed to harvest in a conventional feedlot once dry lot backgrounding or yearling grazing period is completed. Rations are standard for their region and steers are fed to a target harvest weight of 1,350-1,380 pounds. The USMARC calf-fed group is harvested by early August, while the other two groups are harvested in October due to slower growth during the backgrounding phase.

This same sorting takes place with the fall-born calves with groups of 45 head. One group is shipped to the Central Plain Experimental Research Location near Nunn, CO, and a second group is shipped to the Southern Plains Range Research Station in Woodward, OK. The calves are managed in a long yearling program on native summer rangelands in Colorado and a variety of summer forage crops in OK while a third group is placed in the feedlot at USMARC until harvest. The stocker calves in OK and CO are fed to harvest in a conventional feedlot with standard rations for the region, and all three groups are harvested at a target weight of 1,350-1,380 pounds.

For the fall and spring groups, comprehensive growth and feed consumption data are collected along with DNA samples and health and well-being information. In addition, rumen samples are collected from each animal to examine changes in the diverse microbial populations in the rumen from group to group. The rumen samples collected across the three production systems in the study may point to opportunities to improve growth or feed efficiency specific to local environmental conditions or management systems.

Animal stress and well-being are other areas of interest to scientists. Because in this study, the research cattle are handled many times to collect weights and rumen samples, researchers are also collecting blood, fecal, and hair samples during each handling session to monitor differences in cortisol levels, which are a measure of animal stress. Using these measures, scientists can assess stress levels across breeds, environments, handling systems, and production systems, with a goal to improve overall animal management. The measured stress levels can be related back to the genetic, environmental, and management effects being evaluated in the project, which should inform better animal handling procedures, and/or management interventions which improve both animal productivity as well as health and well-being.

This project has completed three years of sampling for spring calves so stay tuned for more information!

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