Researcher studies ways to help cows bear more calves

By Argen Duncan: PNT Senior Writer

An animal scientist’s research is exploring ways to save dairy farmers thousands of dollars a year by helping prevent miscarriages in cows.

Eastern New Mexico University Assistant Professor Darron L. Smith said research suggests a “significant number” of dairy cattle pregnancies — 17 percent to 20 percent — are lost from the 35th to the 45th day of gestation.

Smith’s research has shown that increased insulin levels due to starchy food raise the amounts of progesterone, a hormone necessary for maintaining pregnancy, in cattle. He hopes to find a way to increase those insulin levels without decreasing milk production.

Dairy farmers want every cow to have a calf every year to maintain her milk production.

Smith estimated that cows around Portales must usually be bred two or three times before they have a lasting pregnancy.

Breeding a cow brings expenses from labor, supplies for artificial insemination and possibly hormone treatments. One tube of semen costs an average of $50 and hormone treatments are about $12 per cow, Smith said.

“It’s hundreds and hundreds of dollars,” he said.

Also, Smith said for each day beyond the 100th day after a cow had a calf, dairies see a $3-4 daily loss each day for a cow thatisn’t pregnant.

Alan Anderson of Anderson Dairy said abortions in his herd are a concern, but not enough to make buying a progesterone-increasing product a top management priority. Higher progesterone levels wouldn’t help prevent all miscarriages, particularly those caused by twins or disease, Anderson said.

Smith is studying how progesterone levels respond to other hormones.

Working with other scientists, he previously proved that sugars from starchy feed like grain spike cattle insulin levels — insulin inhibits the creation of enzymes that remove progesterone.

Simply, less enzymes equals more progesterone, equals a better chance of healthy deliveries.

Now, Smith and undergraduate students are examining whether a hormone identical to insulin from the liver will have the same effect on progesterone. They have been working with liver cell cultures in a lab, but Smith is applying for a grant to work on a dairy as well.

The key is spiking the insulin without decreasing milk production,