The campaign comes at a promising time for the egg industry, with the nation's protein craze helping fuel sales after decades of eggs being viewed as cholesterol bombs. [...] last month, a government advisory panel helping shape new dietary guidelines said the available evidence shows no significant relationship between heart disease and dietary cholesterol. [...] the egg industry — in which about 175 companies account for 99 percent of the laying hens — is also dealing with new regulations and scrutiny over animal welfare. Paul Shapiro, vice president for farm animal protection at the Human Society of the United States, said the law was interpreted by many at the time of its passage to mean chickens should be cage-free, but that some egg producers have since disputed that position.