Years of very precise breeding means that modern poultry grow to massive sizes very quickly — sometimes in a matter of weeks. While this results in more meat in less time, it’s also causing a problem: Some birds are so top-heavy that they may not be all that interested in breeding, and there’s now an older breeding population of roosters and hens that are less likely to produce viable eggs.

The thing is, there’s a vast industry that relies on fertile and frisky chickens for breeding are.

Americans have a bottomless hunger for chicken, turning it into everything from taco shells to “fries,” and we also export the meat to other countries. Every month, the U.S. poultry industry needs 750 million new birds to raise and slaughter.

Let’s say that 1% fewer eggs hatch and produce healthy chicks compared to in the past. According to the Wall Street Journal, industry analysts figured out that the poultry industry has lost $121 million in sales because of these chicks that were never hatched.

Solving this problem may not be so simple; the poultry industry hasn’t quite pinned down what is causing the chicken fertility to fall. There are multiple hypotheses, and it could be a combination of factors. Chickens reach six pounds when they’re only seven weeks old, and are twice as big as the breeds that preceded them.

Overfeeding and underfeeding birds both affect their libidos and health, which means that each bird needs very precise nutrition.

“These birds can grow to become big ol’ couch potatoes,” the corporate veterinarian for one big chicken processor told the WSJ.

Chickens don’t have couches or TVs, but when they’re top-heavy and lazy, roosters aren’t very motivated to do their one job. A shortage of chicks could mean higher prices for chicken in the near future, unless experts figure out a way to keep the birds, um, motivated.

Want more consumer news? Visit our parent organization, Consumer Reports, for the latest on scams, recalls, and other consumer issues.