Dr. Justin Sexten is the Development Director for Certified Angus Beef (CAB)

We’ve seen a declining inventory of beef cows since the 1970s, with a couple of partial recoveries. Now that a fairly steady 20-year decline hit bottom a year ago, we have to wonder how many cows our market and resources can sustain.

CattleFax estimates the beef cow inventory grew from around 29 million at the start of 2014 to 30.7 million head as 2015 came to a close. Depending on consumer responses and producers’ ability to satisfy the growing demand for higher quality, some economists suggest the U.S. could support 33 million cows or more by the end of this decade. It remains to be seen how steady the expansion can be in the face of a near-30% decline in calf prices that could discourage producers from retaining as many replacement heifers.

Those are big-picture concerns, and “big” is a word to examine in the smaller picture of individual cow size as well. Any talk about how big our cowherd can be must include how big our cows have become and why. As the cow inventory began to decline 40 years ago, carcass weight began a steady increase to nearly 300 lb. heavier now. Sometimes that increase was only 5 lb. a year, but sometimes, like last year, it was extreme. The 930-lb. average steer weights seen in October were 30 lb. higher than the previous fall.

The heavier carcass weights came from a favorable cost of gain and – for a long time – higher cattle prices.

Carcass weights are leveling off but history suggests they will merely fall back to the lower average increase. A 40-year trend that rewarded more pounds per animal certainly had an impact on the size of cows on farms and ranches.

Feedyard demand for calves with the growth potential to hit heavier finished targets boosted demand for bulls with more growth genetics. Some producers are left with much larger cows and questions about whether they fit the ranch environment.

Matching the cow to the environment is a complex issue because no two are the same. Some say there are massive regions with similar enough environments for an “average cow.” I will grant that for the biological environment, but management and economics are very different, not only across state lines but across the road.

How each rancher selects, culls, manages and markets their cowherd over time is a critical component of the environment. Matching cows to all those resources first requires a set of goals. To paraphrase Dirty Harry, a cow-calf producer has got to know their limitations.

To begin making selection progress, you must determine what you can change, what you will not change and what you cannot change. Then design a program around those limitations.

Marketing is one of the greatest operational limits because that’s where you have the least experience, and no individual can do much to change market demand. Therefore, make sure you are producing what the market demands: cattle with the genetics to gain and grade.

The most common management limitation is calving difficulty in heifers. The typical shortage of labor means a cow only fits her environment if she calves unassisted. When there is no surviving calf, its market suitability becomes less important.

Many ranchers are willing to modify environment to help cows adapt nutritionally. Strategic supplementation or improved grazing systems can help cows express their genetic potential. An alternative is efficiency selection, using expected progeny differences (EPDs) based on residual gain or a weighted index such as the $EN from the American Angus Association.

Simply reducing mature size may improve efficiency when comparing weaned calf weight per unit of cow weight, but forage consumed is not directly related to body mass. Residual feed intake testing has shown efficiency is not determined by size alone.

The “growing” cowherd will continue to change the market, and how ranchers manage their operations. As this new year begins, spend time considering the opportunities and limitations in your operation that lead to better matching cows to your management, marketing and nutritional environments.