by International Brangus Breeders Association Executive Vice President Darrell Wilkes, Ph.D. The International Brangus Breeders Association (IBBA) has been running an advertisement proclaiming that today’s Brangus are, “Not your granddad’s Brangus.” Most breeders can tell simply by looking that the cattle have changed quite significantly over the past couple decades. As Yogi Bear famously said, “You can see a lot just by observing.” Broadly speaking, Brangus breeders have moderated the frame, added base width, added body capacity, increased muscle expression, deepened the flank, tightened the sheath and, in general, made the cattle look more appealing to the majority of observers. While the visible changes are fairly obvious, there are some invisible changes that have occurred in the population that are very important. It is interesting to “look under the hide” at the changes in Brangus.
Today’s Brangus beef fits a white tablecloth menu
Today’s Brangus are high-grading cattle. This statement surprises some people, but it is true and there’s a reason for it. Brangus breeders utilize ultrasound to a high degree to estimate carcass traits on yearling bulls and heifers. This information feeds into IBBA’s cutting-edge genetic evaluation which computes the breed’s EPDs. What may surprise many is that the average value for percent intramuscular fat (IMF) now exceeds 4 percent. What does that mean? IMF is an indicator of marbling, which is the primary determinant of USDA quality grade (Select, Choice, Prime). Meat scientists report that 4 percent IMF generally places an animal in the Choice quality grade. This would be impressive if the animals being ultrasounded were steers and heifers on a high concentrate ration in a feedlot. But these are yearling bulls being fed a grow ration – and they have high levels of natural testosterone which works in favor of muscling and against deposition of IMF (marbling). The Brangus data also includes yearling heifers which are developed on grass or forage-based rations and they STILL have enough IMF to grade Choice. And they only have a quarter inch of backfat on average when they are ultrasounded. One has to speculate, what percent IMF would be present if these same cattle would have been on a high concentrate ration in a feedlot for 160 or more days and delivered to a packer with .50 to .60 inches of backfat? The number would easily rise to 5.5 to 6.5 percent IMF which places them in the middle of the Choice grade. It is no 44 California Cattleman September 2020
wonder then, that we see the data or hear of results of pens of Brangus steers or heifers grading more than 90 percent Choice, with 20 to 40 percent making Certified Angus Beef, and up to or exceeding 10 percent Prime. This is entirely consistent with the genetic trend in Brangus for marbling. It’s not a fluke. “I can remember back when a Brangus broke a 3 percent IMF scan, we were doing handstands! Today, Brangus are scanning IMF’s better than the top end Angus cattle. Better overall, in fact, because of the Brangus cattle’s high yields. For a balance of yield and quality grade, you just can’t beat a Brangus,” says ultrasound technician, Donnie Robertson. Your granddad’s Brangus did not marble like this – or very few of them did. The beef industry across the board has increased the percentage of cattle that grade Choice or higher. The average is now on top of 80 percent Choice, compared to 60 to 65 percent Choice less than a decade ago. Brangus breeders take pride in doing their part to improve the quality of U.S. beef. This is due to genetic change. Marbling is heritable. If one has access to state-of-the-art genetic evaluation (i.e. computation of EPDs), along with access to good genomic tests (DNA tests) which enhance EPD accuracy, and if breeders place emphasis on marbling in their selection, you can move the curve – which is exactly what Brangus seedstock breeders have done. The chart above compares the actual IMF averages with the EPDs for IMF over the past 19 years. Clearly, the actual IMF increase is steeper than the EPD line, but this is expected. EPDs tend to be conservative. Moreover, the EPD is only half of the actual genetic level of the animals because an EPD is an estimate of the effect that a random sample of 50 percent of an animal’s genes will have on his/her progeny. The key point is that Brangus breeders are moving the average higher and have been doing so for 20 years or longer. Very importantly, the average has reached the point where Brangus genetics are clearly making a positive contribution to the grading profile of the higher-quality beef industry of today.
How about muscling?
Granddad’s Brangus had a reputation for being a bit flat-muscled. Current data on Brangus make it clear that this is an outdated perception. Today’s Brangus cattle have muscling that places them above average in the U.S. cattle population. Ultrasound is used to estimate the size of the rib eye
