Written by: Matt Woolfolk, ASA Director of Performance Programs

Hopefully, by the time this issue reaches your inbox, you have seen the changes to our selection index offering implemented in Digital Beef. If it’s your prerogative, you’ve taken the time to study how the changes to the $Feedlot formula are reflected in your herd, as well as the addition of the Cow Productivity Index (CPI). As the new index on the page, there’s undoubtedly questions about how it works. This article will walk through some of that aiming to give you a better understanding of CPI.

Let’s start with the breeding objective that defines CPI and, thus, the traits that get included in the model. This index mirrors the production scenario in which Shorthorn genetics are going to be most often utilized in the commercial sector: to produce own replacement heifers and steers that are a payday for their producer as feeder calves. As seedstock producers, we have been told over and over that the commercial cattleman wants cattle that don’t cause them problems, most recently by panel members Brian McCulloh, Dale Stith, and Jim Akers at Summer Symposium. Either that mantra is truly so important that it must be repeated, or we aren’t doing a very good job of it, so they must keep telling us. The goal of CPI is to help identify those genetics that we might classify as less apt to cause problems: calve on their own, raise a good calf to the weaning pen, keep doing it year after year without getting bigger cows than a rancher might want.

With that in mind, the traits that fit this index according to the economic model are described below:

Calving Ease Direct (CED) – It’s no secret that the first key to having a profitable calf is getting it into this world safe and alive. The CED EPD is a prioritized part of CPI for that reason. We don’t want calving issues, and neither do our customers.

Weaning Weight (WW) – The end marketing point utilized in the building of CPI is selling calves by the pound as weaned feeders. Obviously, that makes weaning growth genetics a significant component of CPI.

Yearling Weight (YW) – The YW EPD is included in CPI as the indicator trait of mature cow size and is weighted negatively in the index. While a genetic tool for cow weight is in the works at IGS (our genetic evaluation service provider), it is not available for use in our evaluations yet. Genetic studies have shown the correlation between yearling weight and mature weight to range from 75 to 85%. Of note, our BMI formulation has been put together in this same way since its inception, with YW being a negatively weighted part of that index as an indicator for moderating mature cow size as well.

Milk – Cows need to be able to produce enough milk to raise a healthy calf. While our hardest EPD to track, MILK is an important EPD in maternal selection. Too little MILK can leave you disappointed in your cows’ production. We also know that too much MILK can be an issue if you do not have the environmental resources to support heavier milking cows. The MILK EPD is included in a positive weighting in CPI.

Calving Ease Maternal (CEM) – If the goal is producing daughters that can go to work as productive cows, then they need to be able to have their first calf with no troubles. With that in mind, CEM is a part of CPI, albeit the least emphasized of the incorporated traits.

Stayability (STAY) – Longevity is a key to profitability for a cow. The longer she produces, the better chance she becomes a moneymaker for you. STAY is our genetic measure of the likelihood of staying in production longer, meaning a higher STAY EPD is predicting a higher chance of hanging around the herd. The STAY EPD is a significant component to CPI’s formulation.

Several times, I have been asked about why specific traits were not included in CPI or weren’t weighted differently. I reference a chat I had with Dr. Troy Rowan as he performed a third-party analysis of CPI where we talked about a “desired gains” index: putting things into an index to make the outcome what we want it to be, without it necessarily fitting the economic models geneticists use to build the index. Instead, Dr. Rowan advocates for selecting for specific EPDs that might not fit into the index alongside of index selection to make genetic progress. If you want to improve marbling or ribeye or any trait with an EPD while still looking at CPI, you can certainly do that by studying that data in conjunction with the CPI index.

A presentation from Dr. Matt Spangler of University of Nebraska during this summer’s BIF Symposium analyzed this topic well, and I encourage you to look it up on www.beefimprovement.org if you are one of those folks who is lucky enough to have free time. His topic was discussing the challenges of selection indexes for producers who don’t market cattle on a carcass quality grid (many indexes utilize this as an endpoint in the index models). In his presentation, Spangler laid out two scenarios and created indexes for them, with the objective in both of keeping replacement females: a “sell steers at weaning index” with EPD selection thresholds for carcass traits (EPDs not included in the index), and a “sell steers on the grid” index with no extra selection pressure for carcass (carcass EPDs were included in index).

The results of his trial were that the index that marketed cattle on the grid pointed him in the right direction for maternally oriented cattle but referred to it as “sub-optimal”. His test was better able to identify them via his sell at weaning index with selection pressures on carcass traits to. With my curiosity now peaked, I applied some of his tactics to our test population of sires for CPI. The chart to the right shows the average CPI for the top 50 bulls that also meet an EPD selection threshold. So, the top left value in the chart would be the average CPI of the top 50 CPI bulls in our test group that also are average or better for their MARB EPD. The top right box makes a stricter selection, cutting the MARB candidates to the top 25%. The same process is carried out for the other 3 EPDs on the table.

As expected, the more intense we make our selection criteria, we potentially sacrifice genetic merit as valued by the index. However, if we are willing to give up a little to apply that selection pressure on other traits, bulls that excel for CPI, carcass, and/or growth are out there to use.

There’s a lot to unpack any time that a new selection tool is introduced, and CPI is no different. Educating yourself on the available tools will always be important. Knowledge is power, and with knowledge of the tools that best suit your operation, your power to breed and improve Shorthorn cattle increases.

written by Matt Woolfolk, ASA Director of Performance Programs

“When the winds of change blow, some people build walls. Others build windmills.” -Chinese proverb

The winds of change are blowing in the realm of Shorthorn genetic evaluation. Our selection index lineup has remained constant for over a decade. Anyone who has paid attention to the beef cattle industry knows that there has been massive change in all segments over that timeframe. Our genetic offerings will do the same. These updates are the most significant changes to our genetic evaluation since the implementation of weekly runs and single-step calculation methods from IGS in 2018. This isn’t a decision that was made hastily or taken lightly. Rather, the staff has been in the works on this process for close to three years. When this project began, I had zero kids and less gray hair! One of our 2022 Strategic Plan Core Strategies states that we will “Invest in research and development to enable breed improvement.” These decisions were made with that core premise in mind, to enable improvement of Shorthorn genetics.

A staff-led evaluation of our current index offerings and other tools used in the industry led to initial trials of building new selection tools and attempts to modify current ones. After working through this for about a year, a proposal was taken to the board for the creation of a new index and modifications to an index already in the lineup. We all felt it would be beneficial to get breeder feedback in a test period, so late 2023 a trial run was done with a dozen herds with breeders providing feedback to help us improve the product. I think it is important to note that only staff, our consulting geneticists, and DigitalBeef support staff have ever seen the index formulas. NO BREEDER OR BOARD MEMBER has ever seen the index formulas. That misinformation is out there and is 100% incorrect.

As we entered 2024, breeder feedback was compiled and carefully considered as we moved into another round of modifications. I can’t say that all feedback was reflected in this round, because in some instances we got opposite opinions on matters, making it impossible to include both. In the spring, we wanted to bring in an expert from industry to dissect and offer insights to improve our near finished product. Enter Dr. Troy Rowan from the University of Tennessee to get an outside set of eyes on our work and give valuable feedback that brought us to the final product after a couple more rounds of slight changes. That final version is what we are excited to publish for the first time in the genetic evaluation run that will be released the week of August 19.

For those of you that may not know, our indexes (and all others in the seedstock industry) are created using computer models and programs to simulate breeding cattle with certain objectives. All these indexes are built using parameters to define the breeding goals and economic considerations to mirror the current state of the industry. There is commonality between all our indexes: utilizing Shorthorn genetics on British-based cattle in a crossbreeding system is the primary breeding objectives. From there, the differences come into effect as we select cattle that for different marketing and production purposes.

Now that the background is established, let’s look at what is different in our selection index landscape. One index ($Calving Ease) will see no changes moving forward.

Watch for a Part 2: A Further Evaluation of Cow Productivity Index in the September Shorthorn Country and online next week! 

Charles Rosson of Quaker Hill Farms discusses Shorthorn carcass quality.

Charles Rosson of Quaker Hill Farms explains ShorthornPlus Popularity.

Georgia native Josh White has lived and breathed the beef industry his entire life. Described as “cattle crazy” by his family, Josh now leads efforts at the National Cattlemen’s Beef Association’s as Senior Executive Director of Producer Education and Sustainability, overseeing programs like the Beef Quality Assurance program. Learn more as he outlines the many opportunities for producers to learn about connecting with beef consumers — a skill needed for the survivability of the industry.

To view all the podcasts visit YouTube and search ShorthornASA or on shorthorn.org under News > Shorthorn Bull Pen Podcast