Behind the static, 560-lb. weaning weights
by Justin Sexten, Ph.D.
It looks like weaning weights have gone pretty much nowhere for 15 years. That’s according to a summary of North Dakota State University’s Cow Herd Appraisal of Performance Software (CHAPS) that presents genetic progress as functionally static since 2003. I couldn’t miss that summary, well-publicized and pointed out by just about every contact and source I know.
Static being a relative term—there were fluctuations in the data—weaning weight hovered around 560 pounds (lb.), weaning age was 193 days and average daily gain was 2.5 lb. Seeing the flat trends, author Kris Ringwall suggests genetic progress in the commercial cow-calf sector is “mature.”
The topic came up during a “Bull-Pen Session” at the Range Beef Cow Symposium in Cheyenne, Wyo., in December, where the discussion suggested the beef industry has gone astray, utilizing growth genetics while failing to increase weaning weight but driving cow size up.
Well, some of that rings true. A rise in cow mature weight is evidenced by the increasing yearling weight EPD (expected progeny difference) in all major breeds. But combine that with a steady increase in fed-cattle carcass weights for more than 15 years and the idea that weaning weight remains static seems to defy logic.
CHAPS is not alone in documenting the static trend. David Lalman at Oklahoma State University summarized several data sets across the country with similar results at Cattlemen’s College last year.
How do weights at one sector level off while growing steadily at another? Genotype and environment combine to produce a phenotype. Across the beef industry, genotypic growth potential has certainly grown, as all segments demanded. Virtually no one aims to go backward, in genetics or any other production technologies.
But how many cow-calf producers aspire to participate in any other segment? To the extent that number remains static, weaning weights appear static.Genetic progress aside, two aspects of this “static” equation remain constant in most operations that govern this progress.
The environment for those genetics limit their expression at the commercial cow-calf level, lush environments less so than herds restricted by that governor. Keep in mind environment is no physical location; differences in your pasture or range management offer differing nutrients; abundant and restricted supplies can exist across a fence.
Lalman has shown data where each extra pound of weaning weight requires 27 lb. more dry matter for the cow to make sufficient milk to increase weight gain. That causes some to suggest we should reduce growth potential in all cattle to accommodate the ranch environment, the least-common nutrient denominator. However, challenges arise when we realize the required efficiencies for greater gain in the nutrient-rich environments further down the supply chain.
That’s where the second aspect of the equation is often ignored. The CHAPS summary notes that these static and historical weights are matched with a historically static marketing program. It’s a program where least and greatest growth potential are typically sold to the next user rather than retained to capitalize on genetic investment.
Imagine the growth you could capture at the ranch level if the same 27 lb. of dry matter the cow needs to increase weaning weight were fed to calves after weaning. Even at a poor 9-to-1 feed conversion, you could triple the calf gain compared to feeding it through the cow. Backgrounding calves at the ranch rather than selling your genetic potential at weaning offers not only improvements in nutrient-use efficiency but marketing options of retained ownership or selling weaned, preconditioned calves.
Backgrounding enterprises may not fit every ranching operation, but cattle selected for limited growth don’t fit in any post-weaning feeding operation. And when you don’t retain ownership, you MUST sell to one of those.
As heifers are kept back and sires are purchased this year, look for those that continue to match the ranch environment while offering the next owner upside potential. The tools available to make such decisions have never been more available.
And if you want to understand how important upside potential beyond the ranch can be, try setting up an new enterprise where you are the next owner. ###