Getting EPDs right on show cattle

Originally published in the Western Livestock Journal, Oct 21, 2022

By Dr. Bob Hough

 

There is a common myth that all performance cattle have bad structure and all show cattle have bad EPDs. These beliefs are simply not true on both accounts. For show cattle, it is true that a certain number have lower-than-desired EPDs, but this is generally due to one of two causes. The first is the breeder doesn’t believe in the science of EPDs and therefore ignores them when breeding cattle.

This is a critical mistake, as there are mounds of research that prove they do work. It is also sometimes forgotten that the extra performance a show calf has because of preferential treatment is not heritable. However, the biggest reason EPDs may not reflect a breeder’s cattle is improper data collection.

The most common EPD problem occurs when producers show calves, which forces breeders to pull what are often their best calves out of their contemporary group prior to weaning. This allows producers to give the calves feed and attention to get them ready for an early show. Even worse is when they send the weights of calves being prepared for a show along with the rest of the contemporary group.

This can cause the whole contemporary group to be filtered because its distribution demonstrates nonheritable properties due to incorrect contemporary groupings. If the data is used, the show calves will be grossly overestimated for weight traits. When they have daughters, the weaning weight of their calves will be disproportionate to growth genetics rather than maternal genetics, therefore artificially decreasing the milk EPDs of the dams.

Either way, it is a lose-lose because it will harm the producer either in the short run or the long run when the cattle don’t breed true to their EPDs.

However, you can have your cake and eat it too. An example of one producer doing it right is Kevin Jensen of Jensen Bros. Herefords in Kansas. With new, advanced software to calculate genetic predictions, the use of genomics and complete but strategically timed data collection, Jensen says the EPDs reflect his cattle like never before.

It all starts with data collection, and the key is to get complete and accurate data through weaning on the full contemporary groups. This means taking the birth weights correctly and not just guessing them. Producers that guess birth weights are only fooling themselves. The data in the calculation of EPDs in most breeds is filtered because producer-guessed weights almost never have the normal variation you would see in nature, so they are filtered and don’t go into the EPD calculations. If they are not filtered, your customers will filter you as a supplier when they get big surprises on their calving ease, generally having to pull too many calves or having calves too small and weak.

Jensen weighs all his calves at birth using scales, or in the case of not being able to lift the calves, using hoof tapes. He calves in February and March and collects his weaning weights when he preconditions his calves in August, a month or two before weaning. This way, he has weights on the full contemporary groups that have been managed the same. It also gives him time to give a few calves some better treatment if he decides to show them. In his case, he generally doesn’t creep feed because of the adverse effect on milk production if heifers get too fat. However, creep feeding the whole contemporary group on a fairly low-energy feed like crimped oats is certainly a viable option.

It is extremely important to check with your breed association on what their window is for weaning weight age because if you wean them too young, the data won’t be accepted. If you do wean calves too young and then project the weaning weights out mathematically, you are assuming a linear growth curve from a very young age. That is not the way biology works.

Getting the full, actual birth and weaning weights from legitimate contemporary groups is absolutely critical because with these full contemporary groups, the EPD models can account for selection postweaning. The models assume you will be culling calves after weaning, so it will adjust the better calves’ EPDs to account for the poor calves being culled. It also can account for contemporary groups getting broken up after weaning.

The other thing Jensen said made a huge difference is genomics, particularly with the new single-step EPD models that are now in use. He thinks the EPDs now reflect his cattle accurately. He particularly sees it from co-operators’ calves, which generally have lower base weights in the average of their contemporary groups compared to his home-raised calves. However, the genomics give him the assurance that they have the performance they were bred to have.

Jensen then collects all the postweaning data with the assurance that the data will be properly adjusted for selection because he collected full and legitimate contemporary group weaning weights. He is confident that what he sees with his eyes and what he knows about his cattle will line up with the genetic predictions that the American Hereford Association calculates.

The belief that EPD models aren’t correct for show cattle is simply a fallacy. It takes management and forethought, but EPDs can nail a producer’s cattle correctly, even if they show. First, it takes collecting actual birth and weaning weights on the legitimate contemporary groups. This will mean taking the weaning weights a little earlier than normal and perhaps creep feeding—but not so early that they are out of the window to be accepted by the breed association.

The other thing is to invest in genomics. In an ideal situation, genomics would be collected on all of the healthy calves. This assures their sires and dams’ EPDs are adjusted according to the quality of their calves, making the next generation of calves’ EPDs that much more accurate.

Of course, the EPDs are not going to reflect your cattle when you are guessing weights, incorrectly grouping your calves and not using genomics. If you do this, you are ultimately fooling yourself and your customers. This may allow you to make a splash in the short run, but it will put you out of business in the long run. — Dr. Bob Hough, WLJ correspondent 

 Getting EPDs right on show cattle