PINE BLUFF, Ark.—The intense heat of the past week is taking its toll on the flocks of some Southeast Arkansas poultry farmers, costing them hundreds of birds a day.

“Some of these farmers are running their fans and cooling cells non-stop but are still losing a lot of birds,” said Stephen Stone, a University of Arkansas agricultural extension agent in Lincoln County.

Eddie Beard of Lincoln County said he lost 100 chickens from a house of 45-day-old birds on Wednesday, and 350-400 altogether from eight houses total.

“From about six or seven in the morning until about 10 or 11 at night, I’ve been running fans non-stop in the houses,” Beard said. “During the summer we usually use two to two and a half times more electricity than normal.”

Losing chickens to heat is not a new problem for poultry farmers. But Stone said the recent practice of growing larger birds has compounded the problem. As a chicken grows larger, it is less able to handle high temperatures, he said.

Even a slight difference in the weight of a chicken can have a significant impact on its ability to endure heat. Stone said that, of two farmers Stone spoke to last week, one collected 200 dead birds from a house in one day and the other, whose chickens were only a couple of weeks younger, collected only 40.

The heat is also making it hard for the chickens to put on the additional weight that the poultry companies want, Stone said. The birds have less appetite on extremely hot days, he said.

“Each farmer is on a different production schedule, so the farmers who are just getting baby chickens aren’t having this problem,” Stone said.

According to Stone, one poultry farmer tried a different way of cooling off his chicken houses—he laid sprinkler hose on the roof, and turned on the water.

“He said it helped but he still couldn’t get the temperature where it needs to be,” Stone said.