There's nothing like the fair. Visitors can gorge on deep-fried Oreos, hot beef sundaes and heaps of cotton candy. There are rides, craft displays and, of course, barns full of animals that nonfarmers rarely get to see. Yet there's one day of the fair that's bittersweet and, for some, downright heart-wrenching. Auction day is when many 4-H kids must say goodbye after a year of training, feeding and caring for an animal.Every year there are photos circulating online of crying children on market day. Unlike farmers who often have dozens, if not hundreds, of animals, 4-H children work closely with one or two animals for a year, or even longer if the animal, such as a steer, takes more time to raise.Today there are nearly 6 million participants in the nonprofit 4-H in the United States. The four H's stand for "head, heart, hands and health" and as part of the 4-H pledge, members vow to use these four things for the betterment of "my club, my community, my country and my world."Though these separations between children and animals are hard, they fit with the 4-H slogan, "Learn by doing." Children learn what it actually takes to raise an animal for food and then let it go."There's definitely a relationship," says Marsha Fleeger, a former 4-H'er who grew up on a farm and now covers the organization's events for the Record-Argus, a newspaper in Greenville, Pa. "You spend a lot of time teaching that animal to walk on a halter. There's a difference between the relationship with that animal and one that's part of a herd."While in 4-H, Fleeger showed one cow for eight consecutive years. But she still did not find it that hard to sell. "I can honestly say I looked at it as, and I hate to say this, an opportunity to make some money," Fleeger says. "I wasn't significantly attached."Not everyone does a market project in 4-H — some raise breeding stock or show animals that are more like pets than livestock. There are also 4-H programs that don't involve animals at all — yet for those that do, learning to sell the animal can teach important lessons (and provide some extra cash, too).One of these lessons is "the cycle of life." Jill Wagner, a former 4-H member from Iowa who works in agriculture, says that even when her children were 2 and 3, she tried to emphasize to them that hamburger didn't come from the grocery store, "It came from the cows down the road. Someone took the time to raise and feed and vaccinate and care for that animal so you could have it on your table," Wagner says.You're also learning how to market the animal, explains Heather Shultz, a 4-H extension specialist for livestock programs in Georgia. Not only are children raising the animals and learning the how-tos of vaccinations and record-keeping, 4-H'ers with market animals are also being taught how to add up the costs and weigh them against future profits. That's significant for anyone who hopes to raise animals or keep the family farm running smoothly.Katie Pratt, a corn and soybean farmer from northern Illinois, sold her first market calf when she was 8 years old. "His name was Justin, and he was my best friend. We went to the fair and I got a blue ribbon," she recalls almost wistfully. "When the reality of the fact that he had to go to market hit, it was awful."She says her father still gets teary talking about how hard that day was for his young daughter. But she explains that as a kid whose family's income comes from raising livestock, learning how to care for an animal and then letting it go is important. "I hate to sound crass or blunt, but you get over it," she says.It seems that parents' or 4-H leaders' explanation (or lack of explanation) of what it means to raise a market animal makes the biggest difference for children on market day. "As long as parents take them into it with the understanding that this animal is being sold and not coming home, tears may be shed, but most of them go back to it," Fleeger says. "The rewards are greater than the heartache."Today, parents are more likely to try to shelter their children from the reality of slaughter, says Shultz. "I've seen a shift," she explains. Even with her own children, she recognizes that her automatic response is to shield them. "But I feel by being a transparent parent and explaining everything, it's easier at the end [of the project]."Wagner and her sister grew up raising sheep through 4-H, and despite a few traumatic experiences (Wagner says the first year, their father didn't tell them the animals were meant to go to market until after they were gone), it was a "family effort" and a way for them to spend time together.Now Wagner's children are becoming 4-H age, and while she hopes her daughters will want to show sheep, she won't force them into it. "I remember selling the animals vividly," she says of her own experience. "Of course there was sadness in doing that but it's something I think is good for kids to understand." Maybe it was that sadness that taught her to appreciate where her food comes from and the effort and occasional heartache that goes into caring for any living creature."I see how much my kids, who know where food comes from, waste," Wagner says. "The amount of waste in schools and even in households is really upsetting to me because of the process the animals have to go through. We need to appreciate that an animal had to give its life for this meal to land on your table."Tove K. Danovich is a journalist based in Portland, Ore. Copyright 2017 NPR. To see more, visit http://www.npr.org/.