The evaluation of possible herd sires based on their genetic potential can sometimes be confusing for new bull buyers. One factor a bull buyer can get behind in the buying process is that the next herd sire purchased should hopefully gain more profit in the next calf crop. Yet, when looking at the available selection tools such as EPDs to evaluate herd sires, there are so many choices to choose from. So, which EPD should you look at? And is there more than one EPD to compare sires on?An economic index is a tool used to select on multiple traits at once based on a given breeding objective. Essentially, an index looks at both genetic and economic values as well as the relationships between traits in order to select for profit. This is a much easier way to consider multiple traits at once, while only having one value to compare between sires. Let’s take a look at each of the selection indexes available at RAAA.There are three main selection indexes:
Profitability and Sustainability (ProS): This is an all-purpose index which predicts the economic differences of animals for all segments of the beef supply chain. The breeding scenario for this index is that replacement heifers are retained from within the herd and all other remaining progeny are fed out to be harvested on a quality-based grid. Ultimately, this index would be the combination of the two selection indexes and breeding objectives defined below.
The traits included within this index are Calving Ease, growth traits, Milk (MILK), Mature Weight (MW), Heifer Pregnancy (HPG), Stayability (STAY), Dry Matter Intake (DMI), Average Daily Gain (ADG), and carcass traits (BF, CW, MARB and REA).
HerdBuilder (HB): This is a maternal selection index which predicts the economic differences of animals for traits that are important from conception to weaning. The breeding scenario for this index is that bulls are mated to both heifers and cows, replacement heifers are retained and all other remaining progeny are marketed at weaning.
The traits included within this index are Calving Ease Direct (CED), Calving Ease Maternal (CEM), Weaning Weight (WW), Milk (MILK), Mature Weight (MW), Heifer Pregnancy (HPG) and Stayability (STAY).
GridMaster (GM): This isa terminal selection index which predicts the economic differences of non-replacement animals through the post-weaning part of production. The breeding scenario for this index is that all progeny are fed out to be harvested on a quality-based grid.
The traits included within this index are Dry Matter Intake (DMI), Average Daily Gain (ADG), Carcass Weight (CW), Back Fat (BF), Marbling (MARB), and Ribeye Area (REA).
Furthermore, all of these indexes are expressed in dollars per head born, thus a larger value will be indicative of a larger dollar profit overall. For instance, let’s compare two bulls on the HB index. Bull A has an index value of 78 and Bull B has an index value of 50. If these bulls are bred to a comparable set of females, we would expect Bull A’s progeny, on average, to be $28 more profitable per head born, given that these bulls were utilized in a breeding scenario that encompasses retaining replacement females and selling all other progeny at weaning.
One caveat of utilizing economic selection indexes is making sure that your operation matches the breeding scenario. This is an important factor to ensure that your operation is marketing their animals in a similar fashion, allowing for the profit per head to be realized. However, if there are other aspects of your operation that are hard to ascertain, then choosing the all-encompassing breeding scenario, such as in the ProS index, offers a balanced scenario for any operation.
With the bottom-line always being at the forefront of a producer’s mind, an economic index value can be a valuable asset due to being expressed in units we are all familiar with, dollars. An economic selection index takes the daunting task of multiple EPD comparisons between bulls into just one comparison.
This takes the work out of focusing on multiple EPDs and takes less time to evaluate potential herd sires on. One index, one breeding scenario and more profit per head can be the best asset to your operation! — Lindsay Upperman, Ph.D., director of Breed Improvement
