Children Raised on Farms Develop Better Immune Systems

Finally tonight, half of us are sneezing and wheezing from colds and flu and the other half seem just fine, immune. Well, it turns out there is a lot of research showing the best medicine for modern... See More

Finally tonight, half of us are sneezing and wheezing from colds and flu and the other half seem just fine, immune. Well, it turns out there is a lot of research showing the best medicine for modern health could be as close as the barn. Abc's sharyn alfonsi has been digging into the proof. ♪ Reporter: The mcdonald family had a farm. And on that farm they have not one, not two, but nine children. Eight boys, one brave girl, each the picture of health. Why do you think your kids are so healthy? Good genes. Reporter: Good genes help, but it turns out so do the chickens and even those slobbering pigs. It might seem counter-intuitive to a country obsessed with ant anti-bacterial lotion, but those animals could be one of the reasons these kids are so healthy. Do your parents ever say to you, don't touch that, it's dirty? Yeah. Only if it's really dirty. Reporter: One study found families on farms are almost half as likely to have asthma and nearly four times less likely to have hay fever. Researchers say animals help kids grow antibodies to fight infections better. I got up close and personal with rosie. How much milk do you go through with nine kids? Probably two gallons a day. Reporter: Two gallons a day? Well, you better get another cow. But you don't need a pet cow. Exposure to a family cat means a baby will have 6% fewer colds, coughs, ear infections. Babies raised around dogs will have 31% fewer infections. Researchers believe pets may help children's immune systems mature faster. ♪ AND ON THE FARM, the McDonald's make their own music, too. Improving memory, immunity and even muscle tone. Keeping the family and their health in perfect harmony. ♪ sharyn alfonsi, abc news, romulus, new york.