Association Perspective
New indexes for commercial users of Angus genetics.
The American Angus Association recently made updates and an addition to its suite of economic selection indexes first released 15 years ago. These indexes, commonly referred to as dollar values ($Values) and established in 2004, were designed to make selection easier for bull buyers by allowing them to select for multiple traits at once based on a specific breeding objective.
Why change now?
The indexes originally created in 2004 and 2005 have served the industry well; however, cattle and management practices have evolved in the last decade and a half. Due to this, the economic models also needed to evolve. Furthermore, several new traits, or expected progeny differences (EPDs), have been added to the indexes to make them more robust. The addition of these traits has been made possible due to the seedstock providers’ commitment to data collection, allowing the creation of additional selection tools that have economic importance.
The updated $B index rewards cattle that can compete on an above-industry-average carcass grid while avoiding Yield Grade (YG) 4 and 5 carcasses and heavyweight discounts.
This effort led to an updated beef value ($B) model, along with updates to its two counterparts, feedlot ($F) and grid value ($G). Plus, an update to the cow energy model ($EN) and an addition to the Association’s suite of selection tools — maternal weaned calf value ($M). $Values encompass the revenue generated from genetically derived outputs and associated costs (expenses) from required inputs.
$Values only have meaning when used in comparing the relative merit or the ranking of two individuals. Each sire listed in the Sire Evaluation Report is comparable to every other sire. The $Values are sensitive to the assumptions for the industry-relevant components used in calculating the indexes. Angus Genetics Inc. (AGI), the American Angus Association® and Certified Angus Beef LLC (CAB), alongside industry-leader CattleFax, work together to update these economic assumptions annually, which are derived from the previous seven-year market trend rolling average. As with EPDs, variation in $Values between animals indicates expected differences in the relative value of progeny if random mating is assumed. Thus, a $Value has meaning only when used in comparison to the $Value of another animal.
Better tools for selection
$M is a new maternal index that focuses on fertility, functionality and fitness traits such as docility, calving-ease maternal and foot scores. This index, expressed in dollars per head, predicts profitability differences from conception to weaning with the underlying breeding objective assuming that commercial producers retain their own replacement females, replacing 20% of the breeding females per year, and sell all male progeny and the rest of the cull females as feeder calves.
$M includes nine traits with a greater emphasis on maternal traits than any of the other tools currently available. Traits in the $M include calving ease direct (CED) and calving ease maternal (CEM), weaning weight (WW), maternal milk (Milk), mature weight (MW), heifer pregnancy (HP), docility (DOC), foot claw set (Claw) and foot angle (Angle) EPDs. This index finds the most profitable cattle when producers receive no economic benefit for traits affecting postweaning performance. It more readily focuses on the cost side of cow-calf production by putting downward pressure on mature cow size, maintaining progeny weaning weights consistent with today’s production standards and creating a favorable response in foot structure traits.
In the end, producers that utilize this index will be able to better select for weaning performance alongside acceptable calving ease and docility without increasing mature cow weight or jeopardizing fertility, all while having emphasis on foot soundness.
$EN, expressed in dollar savings per cow per year, assesses differences in cow energy requirements as an expected dollar savings difference in daughters of sires. The higher the number, the greater cost savings per year. EPDs directly influencing $EN include Milk and MW. Often producers in tougher environments where feed resources are limited use this tool to find individuals that should be easier to maintain normally by being smaller in size with less milk production. This tool can be used in combination with $M to fine-tune the cow herd to tailor those females to a limited feed resource environment.
On the other hand, $B is a terminal index, expressed in dollars per carcass, aiming to predict postweaning profitability differences for feedlot and carcass merit. It assumes all progeny, both males and females, will be sent to the feedlot and sold on a carcass-merit grid. The new $B model more correctly aligns with today’s heavier fed-cattle weights resulting from feeders aiming to capture carcass quality premiums.
One effect of the new model is to slightly lessen the current impact of carcass weight and place a greater emphasis on marbling and yield. Overall, carcass weights will continue to increase under this new model but with a higher premium for increased quality grade. EPDs directly affecting the index include: yearling weight (YW), dry-matter intake (DMI), carcass weight (CW), marbling (Marb), ribeye area (RE) and fat thickness (Fat). Selection on the new $B will result in more profitable feeder cattle when fed through to slaughter in today’s market with payments made on a quality-focused grid. The updated $B index rewards cattle that can compete on an above-industry-average carcass grid while avoiding yield grade (YG) 4 and 5 carcasses and heavyweight discounts.
Angus $Values have been designed and updated to make genetic improvement easier and more effective for commercial producers given their target or goal. It is imperative to understand the breeding objective that is specific for each $Value listed above and use that index accordingly.
For more information about Angus indexes, visit www.angus.org/index.
