University of Nebraska-Lincoln
A seedstock producer's goal should be faster genetic progress (breeders equation). But, we need to balance this by the cost of the genetic progress.
Although some of these traits are interesting to us as biologist (what Spangler termed "biological intrigue"), what really matters at the end of the day is improving cattle.
What is the difference between an indicator trait and economically relevant traits? Economically relevant traits are traits that directly impact profit by either influencing revenues or expenses. Indicator traits are traits that are recorded because they allow us to more reliably predict economically relevant traits. An example of this would be calving ease direct and birth weight. No one gets paid for or has costs associated with birth weights. But, birth weight is a great indicator of calving ease, because calving ease can have economic impacts through labor, dead calves, cows that don't rebreed, etc.
Which is the economically relevant trait? Residual feed intake or dry matter intake? Residual feed intake is an indicator to make selection decisions. When you feed cattle, you are charged for the actual feed intake, NOT the residual feed intake. Thus, dry matter intake is the economically relevant trait. See Improving Feed Efficiency: Feed Efficiency Project Releases Decision Support Tool for more information.
What is a selection index? When we use an index we select on aggregate merit. The index is a combination of the individual economically relevant traits into a single value, most frequently expressed as a dollar figure.
“There is no easily accessible, objective way for breeders, particularly breeders in the beef and sheep industries where ownership is diverse and production environments vary a great deal, to use these predictions [EPDs] intelligently.”
- BourdonWhat does this quote mean? Does it means EPDs don't work? Does it mean that beef producers are stupid? No, it means that it is nearly impossible for an individual beef producer to identify how to use the entire set of published EPDs. What EPDs should be emphasized? What are appropriate bounds for EPDs?
Luckily there is a very easy solution, economic selection indexes.
What drives profitability?
Hot carcass weight is the main driver of profitability, accounting for 59.5% of the impact on profit. Dry matter intake is also important at 11%.
There are 24 beef operations from 7 states that are part of the weight trait project. This project has been designed as a demonstration project of genomic selection. Through this project came some of the first observations that genomic predictions (at least in their current form) don't work well across multiple breeds. In other words, genomic predictions designed in Angus don't work well in Hereford or even Red Angus. The weight trait project was expanded at the start of the USDA Beef Feed Efficiency project. As part of the demonstration project, they got semen from bulls used by producers in the Weight Trait Project. They produced progeny out of these bulls and put the progeny through a feed intake trial. This data has then been turned over to the breed associations to use in the development of feed intake genetic predictions.
Please visit www.beefefficiency.org and eBEEF.org for more information.