Aviagen Group, the largest producer of breeding chickens, has found that tweaking the genes of its mainstay rooster has rendered the crowing male chickens less fertile. That genetic fallout is set to hit Americans right where it hurts -- in the wallet. The Aviagen roosters, no longer quite cock of the walk, produce about 25% of chickens raised for food in the U.S. Heightened prices of beef and pork have already made demand for chicken soar this barbecue season. But the increasing impotency of the roosters exacerbates an already short supply of breeding chickens, the result of a 2011 boost in feed prices, and consumers will see more expensive broilers. Investors, though, can cash in on two stocks in particular, Tyson Foods and Sanderson Farms.