Ear Tags

Numbered ear tags appear in the ears of a high percentage of cows and calves in southwest Missouri.  They are obviously put there for a reason but some producers may not be using the full potential of those tags for herd management according to Eldon Cole, a livestock specialist with University of Missouri Extension.

“I don’t know of many farmers who take the tags as far as they could to effectively evaluate the individual performance of the cattle in their herd,” said Cole.

Getting individual weights at weaning is the next important step after tagging.

“Not only do a lot of herd owners tag cows and calves, they write down birth dates of calves in pocket-sized books such as the popular Red Book.  From there the data may be entered in a computer,” said Cole.

For a producer to get more information to make breeding and culling decisions, the calf, and maybe even the cow, should be run over a scale

According to Cole, the popular time to do that is at weaning which normally is between 160 and 250 days of age.  Years ago the beef industry adopted the standard weaning age of 205 days to adjust weights to.

“If you know the age of the calf in days and the weaning weight taken between 160 and 250 days, you can more accurately compare the growth of the calves and performance of their dams,” said Cole.

Older calves always look more impressive than the last calf born during a 75 to 90 day calving season.  It is possible though that a bull, heifer or steer born in late October could be a better performer than a herd mate born in mid-August.

“Recently, I adjusted weaning weights on a set of fall-born calves.  The average 205-day weight on the steers was 678 lbs. and the heifers averaged 574 lbs.  I did not adjust for age or dam as they were all mature cows,” said Cole.

The 205-day steer weights varied from 802 lbs. down to 575 lbs.  On the heifer side, the range was 667 down to 470 lbs. Cole says that over the years he has found a 200 lb. spread from best to worst in a sex contemporary group is fairly common.

“I realize cow herd owners do a lot of visual appraisal of their calves and cows when they cull and save replacements.  It’s better to use the ear tag, record the birth date, individually weigh the calves and adjust the weights to a common age along with the visual evaluation.”

Individual weights are the basis for expected progeny differences (EPD) values after they are processed through a breed association’s record program.  Seedstock producers have adopted the EPD technology because they realize it has merit in their breeding programs.

“However, commercial cow-calf producers should consider using a scale and adjusted weights to monitor within herd production.  You will be surprised at the variance in cow productivity,” said Cole.