Proper development, accurate estrus detection and early breeding help maximize heifer productivity

CALDWELL, Idaho — Getting heifers developed, inseminated early and confirmed pregnant plays a significant role in the lifetime productivity of beef and dairy cows.

“Replacement heifers are an investment in the future of beef and dairy operations,” said Joe Dalton, professor and Extension specialist in dairy cattle reproduction at the University of Idaho. “It takes two years to raise a heifer before she starts generating returns.”

Achieving a successful pregnancy from first service breeding, especially when practicing artificial insemination, has the most potential to realize the greatest return on investment for their development.

“There is a difference between an animal that calves at 23 months versus 29 months of age,” Dalton said. “The longer it takes to get a heifer bred, the more it increases management costs and lowers their lifetime potential.”

Why Age Matters

Age at first calving directly impacts the productivity and longevity of beef and dairy replacement heifers. With current calf values, early calving heifers offer greater profit potential for beef and dairy producers.

“Earlier first calving in beef herds brings greater longevity and more lifetime weaned pounds,” Dalton said.

Ideally, beef heifers are selected from cows that calve early in the breeding season so they have more time to develop and can then be bred on first service to calve at the start of their first calving season.

“Heifers that calve early tend to keep calving early and produce more weaned pounds,” Dalton said. “Late-calving heifers rarely catch up or pay off on their $1,500 to $2,500 development costs.”

Most dairy farms don’t have the same seasonality as beef herds, since calving occurs year-round to keep a steady stream of cows in milk, but the same thinking holds true.

“The goal for dairies is to develop heifers that are approximately 22 to 24 months of age at calving,” Dalton said. “The data shows that dairy heifers calving in that age range have more longevity and produce more lifetime milk than older heifers at first calving, which can help sooner recoup development costs that can exceed $2,500.”

Set Up For Reproductive Success

For heifers to conceive on first service and stay productive, it begins with good management practices early in life.

“It all starts when the heifer is born,” Dalton said. “And that sounds like a cliché, but it’s not, because that heifer will carry all of her life experiences with her.”

Beef and dairy heifers require high-quality colostrum after birth to support their immune systems. Then health must be maintained through vaccinations, deworming and timely treatment of illnesses.

Ensure nutrition supports growth to at least 55% of mature weight by breeding at 13 to 15 months of age.

“With nutrition, heifers need to stay in appropriate condition to have the best reproductive outcomes,” the dairy specialist said. “Fertility is lower when they are under- or over-conditioned. It needs to be just right.”

Dalton recommends that dairies have heifers at a body condition score of 2.75 to 3.25 on a 5-point scale. Beef operations should have heifers at a 5 to 6 BCS on a 9-point scale.

“Having heifers at those benchmarks is really beneficial for overall fertility,” Dalton said.

Breed Heifers On Time

Once heifers are developed to their target size goals, it’s time to begin a breeding program. There are some variances in AI breeding protocols between mature cows and heifers.

“The difference is that while heifers respond to synchronization protocols the same as cows, there’s a little bit of variation in heifers in the number of follicular waves,” Dalton said.

A vital component of a breeding protocol to ensure success is to utilize estrus detection through tools, such as an Estrotect Breeding Indicator, to accurately gauge estrus intensity.

“Determining when estrus intensity is at its highest is incredibly important to fertility because the pieces of the puzzle are all where they should be when it comes to hormones and the reproductive tract being ready for insemination,” Dalton said.

“Data has revealed that high estrus intensity leads to increased pregnancy and decreased pregnancy loss for cattle.”

Estrus detection aids, such as breeding indicator patches, help monitor estrus activity and provide a quick visual indication when heifers reach high estrus intensity.

“Accurate estrus detection tells us a heifer is ready to breed,” Dalton said. “Synchronization protocols can combine estrus detection and AI or timed-AI for better pregnancy rates.”

Heifer-specific protocols have been developed by the Dairy Cattle Reproduction Council and the Beef Reproduction Task Force that can be accessed on their websites for specific details.

A cattle reproductive specialist can also help identify which protocol will work best to breed heifers.

“By implementing quality management protocols, you’re better controlling the investment in developing heifers so they can become productive members of the herd,” Dalton said.

“For both beef and dairy producers, earlier age at first calving results in lower costs and higher lifetime productivity.”