PRODUCERS MUST MAKE OBVIOUS CULLING DECISIONS IN THE SPRING

by: Ted G. Dyer
UGA Extension Animal Scientist


With the annual cost of keeping a commercial cow at or around $400/year, it is critical to identify and cull those open cows as soon as possible. Each day they remain in your herd it costs you more than $1/day. Therefore, several dollars can be saved by using the most basic trait (REPRODUCTION) to make culling decisions determining whether females breed or not. Heifers should calve at two years of age and raise a calf to weaning. Cows should rebreed and calve every 365 days or less under the environment in which they are maintained with a minimum of supplemental feed.

Open cows are the greatest contributor to a low weaning percentage (# calves weaned/ # cows exposed at breeding). On the average, a cow that does not breed one time will lose 15-20 percent of her lifetime production potential. Furthermore, it will take the net return from two or three productive cows to pay for the maintenance of the open cow. Finally, the percent calf crop weaned has an impact on the culling/selection program by altering the number of heifers needed as replacements to maintain a constant herd size. A lower percentage of open cows results in less cows leaving the herd and more heifer calves to select replacements from.

Identify open cows this spring. After the end of the breeding season, examine all cows and heifers for pregnancy. Because heifers should be bred first, they can be examined earlier than cows. Pregnancy checking of heifers can be done by rectal palpation after 35 to 90 days, by ultrasound examination after 30 to 90 days, or by blood analysis after 30 days. A blood test can also determine pregnancy in cows; it should be conducted 30 days post-breeding plus 90 days post-calving to determine pregnancy. Commercial labs are now available to test blood for pregnancy. Keep in mind the blood test can determine pregnancy only. It will not indicate the stage of pregnancy.

For rectal palpations and ultrasound examinations you should use a skilled, experienced individual usually a large-animal veterinarian. Knowledge of the female reproductive tract anatomy and the physiological changes associated with various stages of pregnancy are necessary to become competent at determining pregnancy status.

Summary. Failure to become pregnant accounts for about 75 percent of calf crop reductions. Open cows and heifers should be culled from the herd as soon as possible in the spring or after the breeding season. If a cow is open at weaning time, that means she will not wean another calf for two years. This same period could be used to put a heifer calf into production. Research has shown that heifers that fail to breed the first year and are held over have an average lifetime calf crop of 55 percent, compared to 86 percent for herd mates that become pregnant the first year.

Make your COW HERD more EFFICIENT IDENTIFY AND CULL THOSE OPEN HEIFERS AND COWS EARLY IN THE SEASON.







Google
  Web CattleToday.com

Don't forget to BOOKMARK  
Cattle Today Online!