EPD Updates
Mature Weight and Cow Energy Requirement EPD Released in Research Format
Expected progeny differences (EPD) for mature weight (MW) and cow energy requirement (CER) have been released by the American Simmental Association (ASA) in a research release format. Mature weight and energy requirements have a direct economic impact through cow salvage value and annual feed costs. These EPD provide breeders with tools to better assess cow productivity and efficiency.
The MW and CER EPD were developed by International Genetic Solutions (IGS). IGS and ASA are committed to the development of genetic tools that aid breeders in making selection decisions on economically and commercially relevant traits.
MW EPD:
The MW EPD is expressed as the difference in pounds of cow body weight at six years of age and a body condition score (BCS) of 5. A higher MW EPD indicates a genetic tendency for heavier daughters at maturity, while a lower MW EPD indicates a genetic tendency for lighter daughters at maturity. For example:
Bull A = 100 MW EPD
Bull B = 50 MW EPD
You would expect daughters from Bull B to weigh 50 pounds less, on average, at age six and BCS 5 compared to daughters from Bull A.
Mature cow weights can be collected at any age after yearling. Entire cow groups should be weighed on the same day and within 45 days of weaning their calf. Members are encouraged to take a BCS at the same time as mature weight collection. Entire cow groups should be scored on the same day, and by the same person, for contemporary grouping.
Members can submit weights and BCS for cows of any age between two and 12. Records on the same cow across multiple years are also accepted.
CER EPD:
The CER EPD is expressed as the yearly difference in pounds of total digestible nutrients (TDN) required for a cow aged six years. A lower CER EPD indicates a genetic tendency for daughters that require less energy to support production, while a higher CER EPD indicates a genetic tendency for daughters that have higher energy demands. For example:
Bull A= 100 CER EPD
Bull B= 50 CER EPD
You would expect daughters from Bull B to require 50 pounds of TDN less per year at age six, on average, compared to daughters from Bull A.
Birth weight, milk, and mature weight EPD are utilized in prediction equations to estimate cow energy requirements representing the primary cow energy expenditures: gestation, lactation, and maintenance.
To view the research release of MW and CER EPD on high-use sires and high-accuracy MW and CER EPD animals, click here. As research EPD, these traits will not yet be evaluated weekly or published on an animal page on Herdbook.org.
As part of their development, these EPD have undergone an extensive validation process. Membership is encouraged to review the research release predictions for MW and CER. Members that have feedback on this evaluation or any questions should contact Dr. Elizabeth Dressler, ASA Geneticist, at edressler@simmgene.com.
ASA Releases DMI and $Gain - Frequently Asked Questions
Frequently Asked Questions
The American Simmental Association has officially released the $Gain economic subindex, as well as the Dry Matter Intake (DMI) Expected Progeny Difference (EPD) in an alpha release format on Herdbook. The purpose of these traits is to help breeders better characterize terminal performance by evaluating genetic differences for feed intake and the profitability potential associated with growth relative to intake.
One of the more recent concerns in the business has been related to feed “efficiency” in feeder cattle. The reason for the quotes around “efficiency” is that in many cases, the tools developed to address feed conversion have been related to biological efficiency rather than economic efficiency, which can sometimes be antagonistic to meaningful improvement. A solution to this is the $Gain economic subindex developed by International Genetic Solutions to more appropriately address selection for improved feedlot performance by optimizing the economic efficiency during the finishing phase. Unlike traditional single-trait selection for dry matter intake (DMI) or residual feed intake (RFI), $Gain balances both the economic component of average daily gain (ADG) and DMI, ensuring that the most profitable animals are identified. The result of $Gain is already factored into both $API and $TI, meaning we already factor the relationship of value of gain to the cost of intake in both indexes.
The $Gain prediction is expressed as the difference in daily profitability of animals in the feedlot based on their combination of DMI and ADG expected progeny differences (EPD). ADG is positively weighted by the value of a pound of gain, and DMI is negatively weighted by the cost of a pound of dry matter.
ASA has received questions since the release of DMI and $Gain:
How are DMI and $Gain factored into $API and $TI?
The relationship of the value of gain against the cost of intake is, and has already been, factored into $API and $TI since their inception. Because of the high genetic correlation between growth and intake, a pseudo-prediction for intake was developed using growth phenotypes and integrated into the indexes in the same structure as the $Gain prediction. This pseudo-prediction for intake does not, however, incorporate actual feed intake records, thus the development and subsequent release of DMI. Development is still underway to migrate the new DMI EPD into the calculation of $API and $TI.
Why are the DMI and $Gain predictions only updated monthly?
Currently, the DMI and $Gain evaluation is performed monthly. Development is still underway to integrate the DMI and $Gain evaluation into the weekly IGS multi-breed genetic evaluation. For this reason and until full integration with IGS, the evaluation is initiated at the start of every month with predictions published shortly after.
What should I consider when factoring DMI into my decision making?
Producers should exercise caution when making genetic selections based solely on DMI reduction. Studies have shown there is a high genetic correlation between DMI and Average Daily Gain (ADG), meaning that sole selection for reduced intake can inadvertently lead to slower-growing, smaller-framed cattle. Selection on biological efficiency does not always equate to profitability, thus the recommendation for considering $Gain in your selection decisions.
If you have more questions about evaluating and utilizing DMI and $Gain please contact the ASA office at 406-587-4531.