By Glenn Selk, Oklahoma State University Extension Animal Scientist
Cull cows represent approximately 20% of the gross income of any commercial cow operation. Cull beef cows represent 10% of the beef that is consumed in the United States. Therefore, ranchers should make certain that cow culling is done properly and profitably. Selling cull cows when they will return the most income to the rancher requires knowledge about cull cow health and body condition. Proper cow culling will reduce the chance that a cow carcass is condemned at the packing plant and becomes a money drain for the entire beef industry.
Is she good for another year? At cow culling time, producers often face some tough decisions. Optimum culling of the herd seems to require a sharp crystal ball that could see into the future. Will she keep enough body condition through the winter to rebreed next year? How old is the cow? Is her mouth sound so that she can harvest forage and be nutritionally strong enough to reproduce and raise a big calf? At what age do cows usually start to become less productive?
There is great variability in the longevity of beef cows. Data from large ranches in Florida would indicate that cows are consistent in the rebreeding performance through about 8 years of age. A small decline was noted as cows aged from 8 to 10 years of age. However the most consistent decline in reproductive performance was noted after cows were 10 years of age. A steeper decline in reproductive performance was found as they became 12 years of age. In other words, start to watch for reasons to cull a cow at about age 8. By the time she is 10, look at her very closely and consider culling; as she reaches her 12th year, plan to cull her before she gets health problems or in very poor body condition.
Other reasons to cull cows:
Examine the eye health of the cows. One of the important causes of condemned beef carcasses is still “cancer-eye” cows. Although producers are doing a much better job in recent years of culling cows before “cancer-eye” takes its toll, every cow manager should watch the cows closely for potentially dangerous eye tumors. Watch for small pinkish growths on the upper, lower, or corner eye lids. Also notice growths on the eyeball in the region where the dark of the eye meets with the “white” of the eyeball. Small growths in any of these areas are very likely to become cancerous lesions if left unchecked.
Likewise be aware of cows with heavy wart infestations around the eye socket. Many of these become cancerous over time. Culling these cows while the growth is still small, will allow the cow carcass to be utilized normally. If however, cancer engulfs the eyeball and gets into the lymph nodes around the head, the entire carcass will likely be condemned as not fit for human consumption.
Check the feet and legs. Beef cows must travel over pastures and fields to consume forages and reach water tanks and ponds. Cows with bad stifle joints, severe foot rot infections, or arthritic joints may be subject to substantial carcass trimming when they reach the packing plant. They will be poor producers if allowed to stay on the ranch while severely lame. They may lose body condition, weigh less, and be discounted at the livestock market by the packer buyers. Culling them soon after their injury will help reduce the loss of sale price that may be suffered later. If the cow has been treated for infection, be certain to market the cow AFTER the required withdrawal time of the medicine used to treat her infection.
Bad udders should be culled. One criteria that should be examined to cull cows is udder quality. Beef cattle producers are not as likely to think about udder health and shape as are dairy producers, but this attribute affects cow productivity and should be considered. OSU studied the effect that bad udders had on cow productivity. They found that cows with one or two dry quarters had calves with severely reduced weaning weights (50 – 60 pounds) compared to cows with no dry quarters. Plus, cows with bad udders tend to pass that trait along to daughters that may be kept as replacement heifers.
Two key types of “bad” udders to cull include: the large funnel-shaped teats and weak udder suspension. The large funnel-shaped teats may be indicative of a previous case of mastitis and cause the quarter to be incapable of producing milk. In addition, large teats may be difficult for the newborn calf to get it’s mouth around and receive nourishment and colostrum very early in life. As some cows age, the ligament that separates the two sides of the udder becomes weakened and allows the entire udder to hang very near to the ground. Again it becomes difficult for the newborn calf to find a teat when the udder hangs too close to the ground. Select against these faults and over time your cow herd will improve its udder health.
Cull cows when in moderate body condition. Send older cows to market before they become too thin. Generally, severely emaciated cattle have lightly muscled carcasses with extremely small ribeyes and poor red-meat yield. This greatly lessens the salvage value of such animals. Just as importantly, emaciated cattle are most often those which “go down” in transit, as they lack sufficient energy to remain standing for long periods of time. Severe bruising, excessive carcass trim, increased condemnations, and even death are the net results of emaciation. Very thin cows have a low dressing percentage (weight of the carcass divided by the live weight).
Because of these factors, cow buyers will pay less per pound for very thin, shelly, cull cows. In addition, thin cows will weigh less. As you combine these two factors (weight and price per pound), thin cull cows return many fewer dollars at sale time than if the cow was sold when in moderate body condition. If they are already too thin, a short (45 to 60 days) time in a drylot with a high quality feed will put condition back on the cows very efficiently. There is no need to put excess flesh or fat on cows. They become less efficient at converting feed to bodyweight after about 60 days and the market will not pay for excessive fatness on cows.
Cull any really wild cattle. They are hard on you, and your equipment, and they raise wild calves. Wild calves are poor performers in the feedlot and are more prone to producing dark cutting carcasses as they reach the packing plant. “Dark cutters” are discounted severely when priced on the rail.
Cull open cows. Why feed a cow all winter that will not have a calf next spring? Call your veterinarian, schedule a time for pregnancy checking and find which cows have not bred back. Cull them while they are in good body condition after summer pasture and before you spend $200 or more on the winter feed bill.