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Efficiency testing completed by Midland Bull Test provides producers with economic information

by Wyoming Livestock Roundup

Midland Bull Test places a strong emphasis on sorting the most economically efficient and reproductively sound bulls to the top. As feed costs are often the largest expense in raising cattle, it is important to raise cattle that utilize feed in an efficient manner.  

Efficiency, according to Midland Bull Test, is an independent trait with no correlation to other traits such as fertility, milkability, performance, frame size, body condition and more. Because of this, producers have the ability to select for highly efficient bulls without negatively impacting other traits.  

Additionally, residual feed intake (RFI) which is a measure of efficiency, is a highly heritable production trait, and there is reported to be a 90 percent correlation between the efficiency of a tested bull and the performance of his daughters.  

Being able to identify individual animals with greater feed efficiency and propagating those genetics is how producers could make improvements in the forage and feed efficiency of cattle throughout the country, notes Montana State University Extension Beef Specialist John Paterson.  

Midland Bull Test utilizes RFI and average daily gain (ADG) as indicators of efficiency.  

RFI and ADG 

RFI, according to Paterson, is a calculation of realized feed utilization which concurrently measures differences in metabolic efficiency. The concept of this technology is to measure the amount of feed consumed by an animal for maintenance as well as growth. 

Paterson uses an example of an animal expected to consume 22 pounds of feed daily, however, through data collection we find the animal only consumes 18 pounds of feed per day.  

“This means the four pound reduction in intake is actually a negative RFI value,” he says. “However, one animal consuming 18 pounds of feed per day with another is consuming 26 pounds of feed per day to produce an equal amount of gain is a concern.”  

The answer for producers is easy – the bull consuming less feed to perform just as well as his counterparts will be more sought after.  

To avoid focusing on just one trait, Midland Bull Test utilizes ADG as an additional indicator of efficiency.  

“I think we get into trouble when we look at only a single trait, such as reduced feed intake,” Paterson states. “We want to use those EPDs for birthweight, weaning weight, feedyard performance and carcass characteristics together.”  

He continues, “Let’s use residual feed intakes and this residual feed conversion as one more tool for selecting efficient cattle that still have desired traits we want on the ranch. We need to be measuring traits crucial to the rancher’s profitability.” 

Genetic merit 

Midland Bull Test has the capacity to test 600 bulls on each 70-day test period or 1,000 head per Midland Bull Test cycle. This ability to test a large number of bulls for efficiency and performance traits gives way for advanced cattle genetics.  

According to Midland Bull Test, the key is to identify more efficient cattle. However, feed conversion ratios are highly correlated to increased growth rates, increased total feed intake and increased mature body size. This all translates into an increase in maintenance requirements and when the focus is placed on performance traits, total system efficiency is lost.  

Although, Paterson shares, selection decisions made on the basis of RFI measured post-weaning translate almost immediately into genetic improvement in efficiency in the cowherd.  

“Producers can now select cow families and heifer development practices to improve feed conversion on the ranch,” he says.  

Midland Bull Test comments, “While there is no magic equation to create the perfect animal, RFI offers an opportunity to breed more efficient cattle with the same level of performance to either sell cattle profitably at weaning, maintain the cattle through the feedlot, develop replacement heifers with minimal feed inputs or even increase the carrying capacity of our producers’ most valuable asset – their land.”  

 Information in this article was sourced from the Midland Bull Test website. For more information, visit 

Averi Hales is the editor of the Wyoming Livestock Roundup. Send comments on this article to 

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