Skip to main content

Importance of Pregnancy Detection During a Dry Year

Originally written by Taylor Grussing, former SDSU Extension Cow/Calf Field Specialist.

While moisture has made a comeback in some areas of the Upper Midwest affected by drought this summer, overall we are still below normal rainfall for the year. With weaning wrapping up, pregnant cows should be identified and turned back out to pasture or crop residue. By removing open or even late cows from the herd, valuable feed resources are saved for next year if drought conditions continue.

Some operations greatly reduced herd size earlier this summer to compensate for limited feed resources expected at harvest. At this point, the last thing producers want to do is sell more cows, open or not. Average cow cost in South Dakota is near $650 annually, or about $1.78 per day. Each day cows are open, their expenses are adding up with no calf returns to be received in 2018.

Why Conduct Pregnancy Tests?

Now, practices such as pregnancy checking cost money ($3 - $8 per head), but don’t forget to consider the value this one practice can have on other areas of the cow/calf operation. The overall cost of preg testing the herd is still likely less than it will cost to feed an open cow throughout the winter. Take advantage of the labor available on pregnancy check day to also complete a few more tasks that will make winter go smoother and help compensate for the vet bill.

  • Pregnancy check early to determine AI or early bull bred cows from late bred cows, identify twins, and plan facilities and labor for the calving season.
  • Sort cows into groups to meet nutritional needs. Young heifers and older cows may need to be separated from the rest of the herd to provide more nutrients vs. overfeeding the entire herd to increase energy to a few thinner cows.
  • Tag cows by calving date so it is easier to identify which cows will calve first come calving season (green = February, yellow = March, red = April, etc.)
  • Check conformation of cows and make note of bad feet, legs, teeth, lumps, body condition score, etc. Use this data to create cow groups that may need to be sold, or have more TLC this winter (Example: take this group to the close pasture with a corral vs. trailing them to pasture 5 miles away with no corral).
  • Begin winter parasite control and scour vaccine administration.
  • Weight cows if possible! Knowing average weight of cows in the herd can help with designing rations and calculating feed inventory for the winter.
  • Compare calf weaning weight to cow weight. If cows are not weaning enough of their body weight, should certain cows be culled?
  • Pounds weaned per female exposed is calculated by taking total pounds of weaned calves divided by total cows that were exposed during the breeding season. This value is a key indicator of successful operations as it takes into account weaning weight and reproductive rates. If this number is low, first determine if it is due to poor reproductive rates (breeding, calving) or if is due to genetics or days of age.
  • Set marketing plan for open, late bred, poor-doers and cows culled for other reasons (attitude, feet, udder, etc.) Determine if the current market is profitable or if cows should be fed until prices go higher.

The Bottom Line

A colder than normal winter is projected, leaving cow/calf producers to prepare the cowherd for yet another weather extreme. Pregnancy testing cows and completing some of the above steps can help save winter feed, prepare for calving and place more emphasis on fertility in the cowherd. Discuss your pregnancy results with your herd veterinarian and/or a cow/calf field specialists to see how this year’s weather or drought may have impacted herd reproductive rates.