In more than one state, farmers and egg producers received a statement warning them from using small cages for hens. Although not confirmed yet, the 550 million eggs, which were reported to have been contaminated with salmonella, came from hens that were crammed in a hen house. This hen house was a "battery cages".

The battery cages, according to animal welfare groups, are a wild expression of cruelty against animals, because in these cages the hens do not find proper space to move freely or even to breathe. In addition, most of the time, these cages do not offer high rate of cleanliness, needed for the hens.

As a result, Compass Group, the largest food service provider in the world, are using only cage-free hens, although according to the egg producers, the cage-free hens cost almost twice as the caged hens. The same applies to the eggs as well.

Paul Shapiro, the Senior Director of the End Factory Farming campaign said, "The cage-free movement is not only about providing a humane environment for animals. There is also a strong food-safety component as well".

However, one of the farmers said that the caged hens do not develop any disease, unless a 'tragic' illness spreads. She also added that the diseases are always under control.