Establish High Reproduction Standards for Heifers

John F. Grimes, OSU Extension Beef Coordinator

As we move into the month of June, most cow-calf producers are involved in some aspect of the breeding season. Some are winding down their breeding season while others are just getting started. Last year in the Ohio BEEF Cattle letter we discussed the significant merits of keeping a breeding season as short as possible (“The Shorter the Better!”, Issue #735). The shorter calving season can apply to any herd but should absolutely be utilized in the specific production group known as replacement heifers.

Regardless if you are involved in seedstock or commercial cow-calf production, the lifeblood of any cow-calf operation is the replacement heifer. The replacement heifer represents the most commonly used method to add numbers and new genetics to a typical herd. It can be exciting as well as rewarding to add new genetics from proven cows in your herd or from outside purchases in the form of replacement heifers. If the replacement heifer is managed properly, she can be a tremendous asset to any herd. However, we need to maintain strict reproductive standards on these females for them to be positive additions to the herd.

Since we are in the midst of breeding season for most operations, little can be done to change how they have been developed to this point. The producer is dealing with the hand they’ve been dealt. How we manage them now from a reproductive standpoint can have a big impact on the overall reproductive performance of the herd today and for years to come.

A producer should expect excellent reproductive performance (90% + conception rates) from a properly developed heifer. If she is adequate in size (60-65% of mature weight at puberty), been involved in a sound health program, and has been exposed to a fertile bull or bred artificially with high quality semen, there is little reason that she should not become pregnant in a 60 – 90 day breeding season. Pregnancy status should be determined within 60 days after the conclusion of the breeding season through rectal examination, ultrasound, or available blood tests. The cost of a pregnancy examination or test is a very small investment that can save an operation many dollars compared to the costs of maintaining an open female.

It is difficult to make significant progress with reproductive performance through genetics as reproduction is a lowly heritable trait. However, selection pressure can be a very valuable tool in making progress with reproductive efficiency. By removing sub-fertile heifers that do not conceive during the first breeding season and continuing this practice over time, a producer will eventually develop a herd with improved fertility. If they are difficult to breed as yearlings, they will not become easier to get bred as mature cows!

Keeping the breeding season short has obvious advantages for management decisions relating to herd health, nutrition, reproduction, marketing, etc. Consider this significant impact of shortening the breeding season with heifers. Most folks would consider calving season with first-calf heifers a fairly stressful activity. They generally require more time and attention when compared to mature cows. Do you really want to extend the time period of calving out heifers next winter and spring? I don’t believe you do.

Given the current prices seen in today’s cattle markets, culling heifers with poor reproductive performance should not be a difficult decision. Open yearling heifers can be sold as heavy feeder cattle or fed a finishing ration for a short period and sold as market heifers. Open heifers are selling at a premium price compared to historic levels so take advantage of this marketing opportunity.

An experienced cow-calf producer once told me “You can love your wife, you can love your kids, just don’t love your cows!” I believe that is pretty sound advice. Don’t be afraid to cull those reproductively inefficient heifers early in life. It will pay dividends in the years to come.