John B. Hall, extension animal scientist, beef, says weaning time offers a good opportunity to collect and analyze information for assessing herd reproductive efficiency. Some key numbers to consider, he says, include:

  • Number and percentage of calves weaned: These numbers provide information on overall reproductive status of the herd. Good herds will average a weaning percentage of 83 to 89 percent of all cows that were present at the time of breeding. Better herds will average 90 to 95 percent. Lower weaning percentages indicate either infertility in the breeding herd or high calf loss  —  problems that require further assessment.
  • Age at weaning and distribution of ages: distribution at weaning is an indicator of the “tightness” of the calving season. A long calving season can indicate that too few cows are cycling at the beginning of the breeding season, often due to low body condition at calving or poor nutrition after calving.
  • Average and range of weaning weights of calves: These are indicators of cow milking ability and genetic ability for growth.
  • Percentage of pregnant cows: Good herds should average 88 to 90 percent pregnancy rates with extremely good herds averaging 92 to 95 percent. Open cows suggest nutritional problems, or possibly bull failure
    or disease.
  • Body-condition score of cows: Body-condition scoring cows at weaning allows producers to sort cows into management groups for feeding. Cows need to be in body-condition score 5 to 6 by calving time, Dr. Hall says.