Single Dose of ESTRUMATE® Helps Iowa Producer Dramatically Tighten Calving Window

LA MOTTE, Iowa - When Logan Schmerbach sat in on a reproductive management presentation at his local veterinary clinic, he wasn't expecting a single protocol change to reshape his entire calving season. But after hearing Dr. Todd Bilby, cattle technical services specialist for Merck Animal Health, explain how one dose of ESTRUMATE® (cloprostenol injection) could synchronize estrus and move cows up in the breeding cycle, Schmerbach decided to put the idea to the test.

Schmerbach, an engineer by trade and a third‑generation cattleman at home, manages a cow‑calf herd with his father in eastern Iowa. He approaches the farm the same way he approaches engineering: measure, evaluate, improve.

"I'm a firm believer that the most expensive words said on a farm are, 'that's how we've always done it,'" he said.

Bilby's message was straightforward - a single prostaglandin injection could help more cows cycle earlier, tighten the calving window, and ultimately produce heavier, more uniform calves. For Schmerbach, the potential payoff was too compelling to ignore.

"Heavier, more consistent calves are more marketable, which equals more money," he said.

Veterinarian: One Trip Through the Chute Can Pay Off

Dr. Thomas Lapke, D.V.M., of Rolling Hills Veterinary Service in La Motte and Cascade, works closely with the Schmerbach family. He says only a small percentage of his natural‑service clients use estrus synchronization, often due to concerns about labor or facilities.

"The biggest pushback is labor and facilities," Lapke said. "However, one trip through the chute can result in calves being born three to four weeks earlier, which can easily mean a 30‑ to 40‑pound‑heavier calf by fall and a more consistent calf crop."

Lapke often raises the topic during fall herd evaluations.

"If calves are light, we need to know why," he said. "If a calf is born in April but is only 300 pounds in October, that's a cow problem. But if the calf is light because it was born late, synchronization can fix that by tightening the calving window."

A 55‑Day Calving Window - With One Shot

The Schmerbachs turned out five bulls with 99 cows. Five days later, they ran the herd through the chute and administered a 2 mL dose of ESTRUMATE.

"With one night's worth of time and $300 of product and supplies invested, we tightened up our calving window significantly," Schmerbach said.

The results stunned him.

"When our ultrasound technician came in September, we found that 41 of the 99 cows were bred within an 11‑day period," he said. "All but nine cows were in a 55‑day window, and even those nine still fit inside an 80‑day window."

For a natural‑service herd, that level of front‑loaded conception is uncommon - and highly profitable.

Efficiency Gains That Matter

Lapke emphasizes that synchronization is only one piece of reproductive success. Breeding soundness exams, vaccination programs, parasite control, nutrition, and body condition all play critical roles.

But Schmerbach is convinced the single dose of ESTRUMATE made a measurable difference.

"We gave one simple shot and realized a 50‑percent jump in efficiency when it comes to breeding our cows," he said. "I am extremely impressed and will continue to use ESTRUMATE. It was well worth our time to run them through the chute again."

Important Safety Information

Women of childbearing age, asthmatics, and individuals with respiratory conditions should use extreme caution when handling ESTRUMATE®. The product is readily absorbed through the skin and may cause abortion or bronchospasms. Avoid direct contact; wash immediately with soap and water if accidental exposure occurs.

Do not administer ESTRUMATE to pregnant cows if abortion is not desired. Severe localized post‑injection clostridial infections have been reported, including rare fatal cases. Mild side effects may occur at 50–100 times the recommended dose. Consult the full package insert for complete information.