Sanderson Farms Inc., one of the biggest U.S. chicken producers, is blaming the recent player-protest controversy in the National Football League for slower sales of chicken wings, the game-time favorite.

Wing prices had a banner year for much of 2017, boosting profits at processors like Sanderson. But spot prices slumped in each of the last three months and are now 14 percent lower than a year earlier, according to one U.S. government measure. Amid the NFL dispute, it’s unclear where prices are headed from here, Joe F. Sanderson Jr., chief executive officer of Sanderson, said Thursday on a conference call to discuss earnings call.

“The only thing puzzling me right now is wings,” he said. “We’ve been talking to our wing customers and they’re the ones that are telling us that they’re seeing less traffic in their stores. They attribute that to the NFL.”

Food sellers have differing views on how much impact player protests during the national anthem at NFL games have had on revenue. While Papa John’s International Inc. last month blamed the NFL’s handling of the controversy for hammering pizza sales, Wingstop Inc. said it hadn’t seen any impact from waning football viewership.

Sanderson shares fell 12 percent to $146.83 at 1:37 p.m. in New York, on pace for the worst slump since December 2008. The company posted lower-than-expected earnings per share in the fourth quarter as chicken prices weakened from rising production and hurricane-related disruptions.