Some culling of beef cows occurs in most herds every year. Industry audits generally show that cull cows, bulls and cull dairy cows make up about 20% of the beef available for consumption in the U.S. About half of this group (or 10% of the beef supply) comes from cull beef cows.

Whether culling due to drought or to improve herd productivity, it’s important to understand the values placed on cull cows intended for slaughter, says Glen Selk, Oklahoma State University Extension cattle reproduction specialist.

USDA’s Market News Service reports on four classes of cull cows (not destined to be replacements), divided primarily on fatness. The highest conditioned cull cows are reported as "Breakers.” These are quite fleshy and generally have excellent dressing percentages. Body condition score 7 and above is required to be "Breakers.”

The next class is a more moderate conditioned group of cows called "Boners" or "Boning Utility.” These cows usually fall in the body condition score grades of 5-7. Many well-nourished commercial beef cows would be graded "Boners.”

The last two grades are the "Leans" and "Lights.” These cows are very thin (body condition scores 1-4). In general, these are expected to be lower in dressing percentage than fleshier cows and more easily bruised in transport than cows in better body condition. "Lights" are thin cows that are very small and would have very low hot carcass weights.

Leans and Lights are nearly always lower in price per pound than are the Boners and the Breakers. "Lights" often bring the lowest price per pound because the amount of saleable product is small, even though the overhead costs of slaughtering and processing are about the same as larger, fleshier cows. Also, thin cows are more susceptible to bruising while in transit to market and to the harvest plant. Therefore, more trim loss is likely to occur with thin cull cows than with those in better body condition, Selk says.

Producers who sell cull cows should pay close attention to the market news reports about the price differentials of the cows in these classes, Selk advises. Cull cows that can be fed enough to gain body condition to improve from the Lean class to Boner class can gain weight and gain in value per pound at the same time. Seldom, if ever, does this situation exist elsewhere in the beef business.

Therefore, during the fall and early winter, market your cull cows while still in good enough condition to fall in the Boner grade. If cows are being culled while very thin, consider short term dry lot feeding to take them up in weight and up in grade. This usually can be done in 50-70 days with excellent feed efficiency.

Rarely does it pay to feed enough to move the cows to "Breaker" class. There is very little, if any, price per pound advantage of Breakers over Boners and cows lose feed efficiency if fed to that degree of fatness.

For the cows you do keep in the breeding herd, it’s important to manage them properly during the winter, Selk adds.

First-calf heifers have historically been the toughest females on the ranch to get rebred. They’re being asked to continue to grow, produce milk, repair the reproductive tract, and have enough stored body energy (fat) to return to heat cycles in a short time frame. Two-year-old cows must fill all these energy demands at a time when their mouth is going through the transition from baby teeth to adult teeth.

If these young cows are pastured with the larger, mature cows in the herd, they very likely will be pushed aside when the supplements are being fed in the bunk or on the ground. The result of these adverse conditions for young cows very often is a lack of feed intake and lowered body condition. Of course, lowered body condition in turn results in delayed return to heat cycles and a later calf crop or smaller calf crop the following year.

Long-term data clearly show that the average two-year-old is about 20% smaller than her full-grown herd mates. There is little wonder that the younger cows get pushed away from feed bunks, hay racks, or supplements fed on the ground. The results of the size differences and the need to continue to grow are manifest in the lower body condition scores often noted in the very young cows. In addition, the very old (10 years of age and older) cows are experiencing decline in dental soundness that makes it difficult for them to maintain feed intake and therefore body condition.

If pasture availability will allow, it makes sense to sort very young cows with the very old cows and provide them with a better opportunity to compete for the feed supplies. By doing so, the rancher can improve the re-breeding percentages in the young cows and keep the very old cows from becoming too thin before culling time.
-- Glen Selk, Oklahoma State University Cow-Calf Corner