Strategic Culling Methods

– Jeff Workman, OSU Graduate Research Associate, HCRD and Stephen Boyles, OSU Extension Beef Specialist

What are the reasons or criteria used by a producer to determine those cows that should be culled? The ultimate goal of a cow-calf producer is to have cows that wean live calves once a year. Therefore, a cow must breed relatively early in the breeding season; deliver a live calf; rebreed in an appropriate amount of time; and wean a live calf. Those cows that fail to meet this basic goal are very good cull candidates. Other criteria used should be based on economically important traits. Those traits that make a cow lower quality and of less value should be eliminated.

Guidelines for Culling include: open/loss of calves, late calvers, genetics/herd performance records, old cows, and physical quality checks including eyes, mouths, feet & legs, udders, body condition, disposition, and pregnancy.

Open/loss of calves: Open cows and cows that lose their calves should be considered for culling. The objective is to have the highest percentage of calf crop weaned as economically possible. Open cows cause the greatest reduction to the percentage of calf crop weaned. On the average, a cow that does not breed one time will lose 15 to 20 percent of her lifetime production potential. It will take the net return from two to three productive cows to pay for the maintenance of the open cow. Some managers may choose to give an exceptional open cow another chance if she is very young because of the cost of a replacement. Calf losses at birth also reduce the weaning percentage. These losses can be from a variety of reasons; however, the most common would be dystocia or calving difficulty. Dystocia usually results from the abnormal presentation of the calf and high birth weights. Pelvic measurements of the heifers can also determine potential calving problems. Calf losses sometimes occur between birth and weaning. This may or may not be the fault of the cow. A cow with poor milk production raises an undernourished calf that is more susceptible to disease and death. Calf losses during gestation result in a cow aborting her calf before pregnancy.

Factors that contribute to a reduction in calf crop percentage weaned of cows exposed
Open cows: 16.6%
Calf losses at birth: 6.4%
Calf losses, birth to weaning: 4.1%
Calf losses during gestation: 2.4%
Net calf crop weaned: 70.5%

Late calvers: A producer may choose to use late calvers as cull cows. The cows that calve during the third, fourth, or later calving cycles are identified. The option of moving these cows to a fall calving herd is an alternative. This should only be done with younger cows that do not have an obvious reason for being late calvers. Some reasons for being a late calver may not be the fault of the cow such as an inadequate nutrition program during her heifer development stage. Another reason is breeding heifers at the same time as the cowherd instead of doing the recommended practice of breeding them two to three weeks prior to the rest of the cowherd. Late calvers are more likely to be ready for breeding during the hotter times of the following summer. Heat stressed bulls will have decreased fertility at the time the late calving cows are starting to cycle. For example, a cow that calves on March 15 was bred approximately on June 5. A cow that misses a breeding cycle or two and calved on April 25 had to get bred by a bull on July 15.

Genetics/Herd Performance Records: Keeping quality, accurate records is extremely important in determining which cows may need to be culled. Calf performance can only be measured by keeping records. Record keeping as simple as recording birth dates and weaning weights can be very beneficial. This allows the producer to see what cows may have the best genetics for growth by examining records from all of her progeny. Genetics for good milk production are also very important. The cow should produce enough milk to wean a calf that will reach the weight goal desired. Producers must remember that culling is a better tool for eliminating dysfunctional cows than for building genetic improvement. The vast majority of the genetic capability of a cowherd comes from the last three bulls that were used. However, records of genetic progress can still be valuable in making culling decisions.

Other data that is very helpful in making culling decisions involves the calves at slaughter. The yearling weights, feed efficiency, and carcass data would be very valuable, however, in most cases the producer is unable to acquire this information. This data is very helpful in eliminating cows that lack the genetics for performance and valuable carcass traits. There are some programs available that allow the producer to acquire this data. Using carcass information to make culling decisions may become much more critical as the industry moves towards a value-based marketing system.

Older Cows: Age of cow is another factor to consider in making culling decisions. According to the USDA National Animal Monitoring System 42% of cattle are culled because of age or bad teeth. This was by far the most common reason that they identified. An Australian publication by Roderick Grieve tells producers to cull cows that are older than 10 years because the cows are less productive due to physiological aging and they contribute to the lengthening of the generation interval. A shortened generation interval is advantageous in making genetic progress. However, one should be cautious in setting age limits on ‘commercial’ cows because of the high cost of producing or acquiring replacement heifers. The average cow has paid for herself at 6 years of age; therefore, additional years of production are very valuable. It is good practice to keep cows that continue to produce a live weaned calf and keep themselves in adequate shape. Older cows may decline in production after 11 years. The decision to cull old cows should be made by using careful consideration.

Physical quality checks: Each cow should be examined and evaluated at least once a year to identify possible reasons for culling. The National Cattlemen’s Beef Association identifies seven quality control points to evaluate.

1. Eyes: Cancer eye or Bovine Oscular Neoplasia is a cancerous growth that may appear somewhere on the eye. The rate of growth of this cancer may vary greatly. It is extremely important that detection is made early. Effective treatment can be used through surgery or hot and cold treatment if detection is made soon enough. Cancer eye is detected by observing a small plaque on one of the eyelids or a wart growing out of the eye itself in the later stages. As cancer eye progresses it may enter the animal’s system causing condemnation of the carcass after slaughter. Early detection and culling may save the carcass, thus allowing the producer to receive the full salvage value of the cow. The 1994 National Non-Fed Beef Quality Audit identified cancer eye as the most common reason for condemned carcasses. This disease cost the producer $2.85 per cow per year in the U.S.

2. Mouths: The mouth should be examined to determine the quality of the teeth. A cow should have eight incisor teeth on the bottom of her mouth. Missing teeth or worn teeth causes the cow to be less efficient at grazing and pulling hay from a tightly wrapped bale. The cow must be able to eat enough to produce milk and wean a calf while maintaining adequate condition. Cows with worn teeth, a condition known as necking, in adequate condition may continue to produce for several more years. Cattle with broken or missing teeth that are unable to maintain their condition are good cull candidates.

3. Feet and Legs: Lameness is a serious problem for cattle producers. A cow should have a structurally correct leg with no defects or swollen, infected joints. The lack of mobility causes difficulty in foraging and getting rebred. The producer must be aware of the potential of a lame cow to become a liability. Non-ambulatory cattle have very little value. It is no longer acceptable to take those cattle to the sale barn; therefore, they will have to be euthanized with a total loss of any income.

4. Udders: Udder soundness is a very important aspect to consider when making culling decisions. A good quality udder has good udder suspension with evenly spaced, refined teats that point straight down. Pendulous udders and large funnel shaped teats make cows good cull candidates. Mastitis is also a problem to the beef cow-calf producer. Research shows that mastitis results in significantly lower weaning weights. Dry quarters can also be a problem especially in older cows. A study found that cows with one or two dry quarters had calves with weaning weights that were 50 to 60 pounds lighter than those with no dry quarters.

5. Body Condition: Body condition is a good factor to use in order to select those cows that should be culled. Cows that are too thin may have difficulty surviving the winter. They may also have problems with re-breeding. Thin cows that do calve may have difficulty maintaining their health and producing enough milk to wean a calf. Cows that are too fat also have a greater incidence of reproductive problems. To aid producers in evaluating body condition a body condition score (BCS) has been developed. The scores range from 1 (emaciated) through 9 (very fat or obese). Producers want cattle that have a BCS of 5 to 7. These cattle are moderate to very good in their condition. Those cattle outside of the BCS range of 5 to 7 are candidates for culling. However, those cattle in the BCS range of 5 to 7 are also the most desirable to the non-fed packers and are more valuable when marketed as culls. A study at the University of Arkansas by J. K. Apple found that cows with a BCS of 6 were the most ideal for harvest and the most economical to the producer and the non-fed packers. Producers face a tough decision when those cull cows are outside of the 5 to 7 range. They may elect to hold and feed those thin cattle in order to increase their value.

6. Disposition: Cattle with poor dispositions can cause a variety of problems for the producer and those working with the cattle. It is very obvious that cattle with poor dispositions are more difficult to work with and cause a safety problem for themselves and those in the area. Disposition also affects the performance and carcass characteristics of an animal. Research has shown that cattle with poorer temperament have lower average daily gains and calmer animals have higher average daily gains. The cattle that are berserk are most likely to have the highest incidence of dark cutters. Carcasses considered as dark cutters will be discounted approximately $35 per hundred weight. Crazy cows may produce crazy calves that have reduced feedlot performance and a greater incidence of dark cutting. Culling cows based on disposition is a good practice considering the safety issues and the poor economic impact of excitable cattle.

7. Pregnancy: It is good management to pregnancy check cows every year. This allows the producer to cull earlier rather than having the expense of wintering an open cow. There is also a potential problem with Brucellosis when keeping open cows. An additional good practice is to check the breeding soundness of the bulls to be used in the herd.

In conclusion, culling is the decision of the producer. There are guidelines and suggestions such as these to follow. The guidelines lay out criteria to examine in order to make sound culling decisions. There can be many other reasons for culling identified by the producer. Some experts suggest culling any cow that stands out as being significantly different. This allows the herd to be more consistent and allows the producer to avoid extremes when marketing their calves. Health problems and injuries can lead to culling. Prolapses are a reason to consider culling. There are vaginal and uterine prolapses. The vaginal prolapse can be repaired allowing the cow to breed and calve again; however, the problem has a genetic component. A vaginal prolapse is a good reason to cull. Uterine prolapses occur around calving time. They can be caused by a difficult birth. If repaired correctly, uterine prolapses are less of a risk to occur again.