Visit Your Breed Association Website for Maternal Breed Indexes
By: Kris Ringwall, Beef Specialist, NDSU Extension Service
Hidden treasures for beef producers are the various breed association websites, which are the doorway to better understanding the performance of the cattle available within each breed.
One fairly new addition to sire summaries is a selection index, available from several breed associations. The selection index allows a producer to select bulls based on multiple traits through a single expected progeny difference (EPD) value. The selection index EPD value can meet maternal cow-calf selection or terminal beef production objectives. Today, I highlight the maternal indexes.
The bull registration numbers are the keys that open the door to lots of information and provide a simple approach to review these available selection indexes within a breed. These indexes help group various traits, establish a relative importance for each trait and present the answer as a single EPD value for a particular bull for that particular trait.
The North Dakota State University Extension Service publication “Understanding Expected Progeny Differences for Genetic Improvement in Commercial Beef Herds” (https://www.ag.ndsu.edu/pubs/ansci/beef/as1770.pdf) explains how a selection index is formed for a set of traits that have production importance within the beef cattle industry. The index should correlate with herd production or financial goals and combine performance records with economic weights, then generate a selection index value.
As noted in the publication, in the cattle industry, these generally are reported as dollar values to indicate the amount of profit or savings the producer could expect when utilizing that index. The indexes are utilized the same way as performance EPD traits and do allow for a more streamlined approach to the utilization of multiple traits.
As with all EPD values, without producer goals and objectives, consistent and repeated selection criteria will not be achieved. Producers need to research the various indexes available and make sure the selection end point matches their herd goal. Once that decision is made, then consistently following through in the years to come can accomplish the desired end point.
This sounds complicated, but indexes do work. If a producer is looking for maternal influence within the herd, here are some examples (as noted in the publication):
• The American Hereford Association Baldy Maternal Index (BMI$) is an index to maximize profit for commercial cow-calf producers who use Hereford bulls in rotational crossbreeding programs on Angus-based cows.
• The American Gelbvieh Association $Cow (AGA $Cow) is an index of value expressed in dollars for a replacement female relative to other animals in the herd. AGA $Cow includes stayability, reproductive efficiency, milk, calving ease, moderate mature weight, calf gain, feedlot feed efficiency and carcass value.
• The American Angus Association Weaned Calf Value ($W), an index value expressed in dollars per head, is the expected average difference in future progeny performance for preweaning merit. The $W index includes revenue and cost adjustments associated with differences in birth weight, weaning direct growth, maternal milk and mature cow size.
• The American Angus Association also provides a Cow Energy Value ($EN). This is an interesting maternal index that, according to the American Angus website, assess differences in cow energy requirements, expressed in dollars per cow per year, as an expected dollar savings difference in future daughters of sires. The index assesses the impact of energy intake needed for lactation, along with the difference in mature cow size.
• The American Red Angus Association of America HerdBuilder index (HB) is an index using Red Angus bulls mated to cows and heifers, with replacement heifers retained from within the herd and all remaining progeny sold on a quality-based carcass grid. By using the HerdBuilder index, producers can increase the sustainability of the cow herd and, ultimately, their operation.
• The American Simmental Association All-Purpose Index (API) is an index that evaluates sires for use on the entire cow herd (bred to Angus first-calf heifers and mature cows), with the portion of their daughters required to maintain herd size retained and the remaining heifers and steers put on feed and sold on grade and yield.
Let me repeat: Indexes are great tools, provided the producer has a long-term objective and bulls are selected to meet that objective through time. Study the various indexes available. They are a potential key for beef cattle selection.