April 27, 2010

Big pens might cause death of chicken in poultry farm

As more states move to ban restrictive livestock cages, the campaign to free egg-laying hens from cramped cages and transfer them to pens that are more humane could unintentionally cause deaths among those birds.

Researchers say decades of breeding to make the white leghorn hens that lay most of the nation's eggs more productive have also boosted the birds' territorial instincts, making them prone to pecking attacks so fierce they're often called "cannibalism."

Scientists and egg producers warn that deadly skirmishes that start with feather-plucking and turn into bloody frenzies when a bird's pecking breaks a flockmate's skin will increase if those same aggressive hens are moved from small cages with 5-10 birds to open pens that can hold dozens.

Animal rights groups want those pens to replace the small "battery cages" because hens are so confined they can't even spread their wings.

Seven states have passed laws that will eventually ban or limit different types of livestock cages. Two of those states, California and Michigan, have passed laws that will eventually ban battery cages for chickens, as has the European Union.

Breeders working over several decades chose the most productive birds to reproduce, resulting in white leghorns that each year can lay 300-320 of the large bright-white eggs most popular with Americans.