AP – As more states move to ban restrictive livestock cages, the campaign to free egg-laying hens from cramped cages and shift them to pens animal rights advocates call more humane could be poised to unintentionally boost 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 five to 10 birds to open pens that can hold dozens.
Animal rights groups want those pens to replace the small "battery cages" they call cruel 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 —
As those bans go into effect and more birds move to open pens, a solution may lie in the work of an influential
The easygoing egg-layers Muir has dubbed "Kinder Gentler Birds" don't need their beaks trimmed and blunted, another industry practice deplored by animal rights groups but which is intended to prevent pecking deaths.
Breeders working over several decades chose the most productive birds to reproduce, resulting in white leghorns that each year can lay 300 to 320 of the large bright-white eggs most popular with Americans. Muir said that approach unintentionally produced birds that also have a heightened self-preservation instinct and desire to literally be at the top of the pecking order.
"If you have a lot of birds that want to be top bird there's going to be fighting," Muir said. "If you leave their beaks intact it's a bloodbath. They will literally kill each other. It's kind of a dominance thing. ... They just peck each other to death."
About 5 percent of hens on factory farms die each year from injury and disease. To reduce fights, they are kept in dim lighting in cages where each bird has an average 67 square inches of space, or two-thirds of a sheet of notebook paper.