Explaining the process of how mammals reproduce is a fairly recent concept, in human history. Back when 90 percent of all living people were farmers or herders, kids figured it from what went on around the barn.

Urbanization led to what came to be called, in the U.S., anyway, as “the birds and the bees” discussion.

Perhaps “thoroughbreds” could be added in there, too, given the vivid explanation of the mysteriously poor performance of Animal Kingdom — Kentucky Derby and Dubai World Cup winner — in the Queen Anne Stakes race at Royal Ascot this week.

In thoughts sent to Thoroughbred Daily News, Barry Irwin, part owner of the 5-year-old stallion, was blunt in describing where he thought Animal Kingdom went wrong, just before and during the race, and graphic without being prurient.

Said Irwin:

“About 25 minutes after walking calmly around the pre-parade ring at Royal Ascot today prior to the Group 1 Queen Anne Stakes, Animal Kingdom suddenly stopped, turning his head left as his nostrils flared while he took in a scent, and dropped his penis and started acting stubborn.

“Alice Clapham, his traveling head lad from America, managed to lead him forward, turn him right and then immediately left into his saddling stall.

“I walked right over to the stall, told (trainer) Graham Motion what I had just seen and observed the veins all over Animal Kingdom’s body pop out, as he became clearly agitated. It was patently obvious to me that he caught a whiff of the scent from the lone filly in the 13-horse Group 1.

[Note. It is interesting that Animal Kingdom seems to have been the only stallion in the race to be affected by the presence of the filly.]

“For the next 10 minutes or so, Animal Kingdom advertised his wares to horsemen and women gathered in the paddock prior to the first race.

“I got sick to my stomach, because I knew exactly what was happening: Animal Kingdom was thinking more about the opposite sex than the task at hand. I could see him transform from a focused competitor to a sex machine.

“It was not a simple matter of Animal Kingdom having unsheathed his sword. The personal member was on display for quite a spell. The horse was gone. I told my assistant Brad Weisbord that I wished I could find a small closet to hide in for the next hour, because what was about to happen was not going to be pretty.

“I personally went up to as many members of Team Valor and Arrowfield Stud as I could find, telling them what I had seen and advising them that I was no longer confident that our horse would perform as hoped.

“So distraught had I became at this circumstance, that I didn’t even bother to go to the front side to watch the race in person. I just stayed in the paddock and watched the race unfold on a monitor. All of the hard work our teams had put forth was about to go down the tubes.

“In the race itself, Animal Kingdom was rank to place for the first time in his career. He raced closer than usual and never settled. He ran like an agitated horse.

“When (jockey) John Velasquez figured it was time to turn the horse loose, the favorite gave him nothing and tamely folded up his tent. He tailed off and was beaten off. On the gallop back to the unsaddling area, Animal Kingdom was full of energy and tried to run off, leading the jockey to believe that his mount was not tired at all.

“Other than the Belmont Stakes, in which he was mugged and exited with an injury that required surgery, Animal Kingdom had never failed to run first or second or fire a big effort.

“Regardless of the circumstances being different in today’s race, Animal Kingdom put forth no sort of effort. So what stopped him? Graham Motion suggested that maybe the horse had run one too many races. Others speculated that too much traveling was to blame.

“I am convinced that Animal Kingdom lost his mojo when his stud career began 20 minutes before he ran in the Queen Anne. As one of our racing partners said, sex in the workplace is never a good idea.”Animal Kingdom earlier in the week had shown signs of being studdish while training in Lambourn. Graham Motion saw it, his wife Anita Motion saw it. But nobody thought it would put an end to his Ascot dream.

“I would do it all over again. I think the horse, under normal circumstances, was well up to the challenge. I hope this non-effort does not discourage others from trying. The enthusiasm generated by Ascot and the media was second to none. I feel sorry for Graham Motion, his staff, trainer David Lanigan, his staff and jockey Ted Durcan, because they put their hearts and souls into this venture.

“OK, big guy, we received the message loud and clear. You win! Enough is enough. Best of luck at Arrowfield Stud.”

Animal Kingdom — perhaps the perfect name for the focus of this story — is being retired from racing to give his full attention to breeding.

Birds and bees … and thoroughbreds.