Operating a closed farm that raises its own heifers and uses only artificial insemination, Nathan Brearley of Portland, Mich., thought his dairy cows would be safe from the bird flu that is showing up on dairies across the country.

“I was very, very surprised that we got it because we’re not moving cows around. We’re not moving cows in here. I truck my own cattle … ,” he said.

The dairy also has technology that monitors the cows’ body temperature, activity and rumination.

“So I did figure that if we got it, I would know right away and we would be able to treat the cows that got sick quickly, efficiently and get them through it,” he said during a video conference call hosted by the Center for Dairy Excellence.

He was surprised by the widespread effect on his cattle. It resembled toxic mastitis in how fast it hit and how sick the cows got.

High temperatures

“They feel like crap. Their temperature goes extremely high,” he said.

The average temperature of the sick cows was 5.1 degrees above normal, and even higher in outliers.

“Rumen function is even more negatively affected and long-term negatively affected,” he said.

The dairy milks 500 head and had to cull about 5% because the cows didn’t respond to treatment.

“We just couldn’t get them through, and rumens wouldn’t bounce back,” he said.

The protocol was aspirin twice a day, a rumen-therapy bolus to try to keep rumen population up and help with hydration and a shot of vitamin B for at least three days.

Dehydration

Usually after the first three days, the cows got so dehydrated the crew had to start pumping them with water. The cows were too sick to get up and didn’t want to drink. Water intake went from 40 gallons a day on a high-producing cow to 5 gallons.

At the peak the farm was treating 250 to 300 cows.

“My whole crew probably only slept four hours a night because you’re taking care of that many sick cows,” he said.

His Holsteins usually produce 95 to 100 pounds of milk a day. Milk production in the sick cows dropped to 75 pounds. It was a slow drop and a slower recovery.

“So there was six weeks where we were down significantly in milk production,” he said.

Abortion

Milk production was at 99 pounds per cow at the end of April when bird flu hit and it hasn’t fully recovered.

“They were in that mid-lactation range, and they’re just not able to recover back to where they were,” he said.

Reproduction was also challenged.

“Right off the bat with those high temps, we were aborting calves. I had a half a dozen that were 150-day pregnant or more that spit out calves. And then quite a few other ones that were shorter term,” he said.

In addition there was about a six-week stretch where pregnancy checks were not nearly as good as they were before the flu hit. The cows didn’t show good heats for about a month afterward, and then they weren’t conceiving as well either.

“So there’s definitely some ripple effect that I think is still showing up,” he said.

Bird flu affected at least half of Nathan Brearley’s 500 dairy cows, with initial losses estimated at $100,000.

In hindsight, we would have done a couple of things differently in treating them, including:

• Push more water and maybe some electrolytes to the cows he thought were sick.

• Be better prepared with electric or gas motor pumps to get water into the cows.