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The Beefmaster Pay Weight
www.beefmasters.org
Cattlemens News Heterosis
by Troy Rowan, Assistant Professor and Extension Specialist (Beef Genetics) As producers, we should always be striving to make the most profitable decisions for our herd. While I’m not an economist, I have a pretty good handle on the two pieces that make up profitability: Revenue and costs. When it comes to genetic selection, I think we have historically done a great job of selecting for traits that increase our revenue like having a live calf and weaning weight. However, when it comes to the “cost” traits, especially those that deal with cow efficiency, selection can be less straightforward. Long-lived cows are the cornerstone of a profitable commercial cowherd. Making these efficient, fertile, sound, and productive females is paramount for a commercial herd to be profitable. There are precious few “can’t lose” propositions in the world, especially when it comes to our bottom line in the cattle business. Crossbreeding is one of those actions that a commercial herd simply can’t afford to skip. The advantage that crossbred animals experience from heterosis, or
hybrid vigor, affects all of the traits that we know drive profitability: from weaned calf pounds to cow fertility and longevity. If we’re not taking advantage of crossbreeding and heterosis, we’re leaving dollars on the table! The benefits of crossbreeding are twofold. First, it allows us to take advantage of breed complementarity. This means that we can match the strengths of different breeds, stacking favorable traits to get the best of both worlds in our crosses. This might mean crossing a strong maternal Angus/ Hereford female with a leangrowth Charolais or Limousin sire. It could also mean using a Bos indicus-influenced breed on a British-based commercial
cowherd to add some tolerance to heat and/or fescue stress in certain regions of the country. The other major benefit of crossbreeding is heterosis or hybrid vigor. When we breed two animals of the same breed, we’d expect that the offspring’s performance would lie around the average of the two parents. We call this the “midparent” value. Heterosis is the overperformance of crossbred offspring when compared to the average performance of
the two parent lines. When we crossbreed animals, we see boosts in performance across traits. The amount of heterosis that a crossbred animal experiences depends on two things: How different the parental breeds are, and how heritable a particular trait is. The more distantly related two breeds are, the more heterosis we would expect to see from their crossbred offspring.
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