He added that the pardons would be popular among the gathered news media because “after all, turkeys are closely related to vultures.” Then he paused, seeming to review a speech he was seeing for the first time as he delivered it.

“I don’t know if I like that line,” he said, “but there is a little truth to it.”

Either way, Mr. Trump seemed to welcome the diversion of a campy event on this most cozy American holiday. As with his predecessors, he offered a few sentences of traditional Thanksgiving gratitude.

“As we gather this week with loved ones across our beautiful land, we give thanks to God for the many gifts he has bestowed upon us,” the president said, after singling out a trio of Republican lawmakers, including Representative Mark Meadows of North Carolina, for special praise. “Today, we also come together to honor the beautiful, feathered friend — the noble turkey. Now, that’s a beauty.”

The annual White House event dates to 1947, when President Harry S. Truman was officially presented with a Thanksgiving turkey. President John F. Kennedy was the first to spare the designated bird rather than ingesting it, as his predecessors did. “We’ll just let this one grow,” Mr. Kennedy said of the lucky fowl, photographed with a “Good Eating, Mr. President!” sign around its neck.

President Ronald Reagan was the first to use the word “pardon,” then President George Bush formalized it and a tradition was born.

This year’s pageant came a day after another animal-themed amusement: Monday’s Rose Garden visit from Conan the hero dog, who was injured in a raid last month while chasing down the Islamic State mastermind Abu Bakr al-Baghdadi in Syria. Mr. Trump, who is the first president since 1897 not to have a dog in the White House, left the petting of Conan to Vice President Mike Pence throughout the ceremony.

On Tuesday, when it came time for the actual turkey pardon, Mr. Trump rose to the occasion.

“Butter, let’s talk to you for a second because I’m going to do something that you’re going to be very happy about,” the president said. “Butter, I wish you a lot of luck. I hereby grant you a full and complete pardon. Full and complete.” Bread, the alternate, was also saved.