Processing of fall weaned calves and pregnancy determination will soon be here, and management of open cows is critical to the financial bottom line of a cow/calf operation. It is estimated that 15 to 20% of a cow/calf enterprise revenue comes from cull cows. Determining open cow(s) early allows producers to select the best strategies that targets the highest potential revenue.

The first question is often why should I pregnancy test? Dr. George Perry highlighted the expenses to run an open cow through the winter months with no calf for revenue. In his example maintaining cows (bred or open) during the winter costs approximately $1.30 per day. This would result in roughly $270 per cow for wintering costs. For a herd of 100 cows where 7 are left open it results in $1,890 left on the table. His article points out the importance of pregnancy determination to reduce costs.

Heather Gessner addressed the strategy of feeding cull cows for weight gain prior to selling them. The seasonal cull cow price pattern is lowest at weaning time (October, November and December) and highest from March through August. Instead of selling cull cows during the lowest price period, adding weight and marketing them at a higher price can be profitable depending on the costs associated with feeding them. The question becomes is the cost of gain less than the additional revenue at the end of the feeding period? Gessner’s iGrow article walks you through the math.

Re-Breeding Open Cows

This iGrow article will focus on re-breeding open cows before taking them to the sale barn. Bred cows “normally” bring more money than cull cows. These newly bred cows would target fall-calving cowherds. The number of fall calving herds appear to be increasing in South Dakota.

Within South Dakota there is a regulation that “no non-virgin and non-pregnant female cattle may be imported, loaned, leased, nor acquired for breeding purposes in South Dakota.” The complete regulation can be found at South Dakota Animal Industry Board. Re-breeding your cows before taking them to market could add value.

If higher than normal open rates occur make sure you work with your veterinarian to determine the potential cause. Breeding-long season pregnancy rates are usually in the range of 94 to 98%. Pregnancy rate is calculated by total number pregnant during the breeding season/number of females exposed to breeding (expressed as a percent). “Normal” pregnancy rates are influenced by several factors such as 1) length of breeding season, 2) body condition score of cows, 3) bull to cow ratios, and 4) health status of bull(s) as well as other factors. So remember to compare pregnancy rate only within your own herd.

Questions to Consider

When determining if re-breeding open cows is the right option for your operation, there are a few questions to consider. Are bulls available for a second breeding season? Using bulls for a second breeding season is often accomplished when producers have both a spring- and fall-calving herd. What is the cost of retaining these open cows through a second breeding season? Using the $1.30 cost per day, should include most expenses such as feed, labor, interest, and utilities. What is the potential income from the bred cow?

Remember not all open cows would fit this program, evaluate each cow to determine if it should remain in any producer’s program. Cull cows often include more than open cows such as those with one or more of the following issues: 1) poor performance, 2) bad udder, 3) temperament, 4) bad eyes, 5) age, 6) structural soundness and 7) health concerns.

A simple cost analysis of this system would be bred cow value minus open cow value. If the difference is higher than the cost of breeding/feeding/etc., it is a profitable system. However, if the difference is lower this may not be the year to utilize this management system. Retaining cows for 90 days at $1.30 per day, would require the bred cow value to be $117 higher than the open cow. If you retained the open cows for rebreeding for 120 days the difference would need to be $156. This calculation did not include the cost for bull use.

Re-breeding open cows will change the value compared to open cows, however, each producer needs to determine if this change is positive.