Dr. Temple Grandin 

FORT COLLINS, Colo. – Almost every day I get either an email or a phone call that another grocery chain or restaurant company is switching to cage-free housing for laying hens. A large scientific study in commercial hen houses clearly showed that the most welfare-friendly alternative for large-scale commercial layer flocks was an enriched colony cage. This system provides amenities that accommodate the behavioral needs of the birds. The major features are:

1) higher ceiling to allow hens to walk normally;

2) a secluded nest box;                       

3) perch; and

4) scratch pads

This study compared conventional cages, enriched colony cages, and cage free. It was led by Joy Mench, professor of animal science and vice chair of the animal science department at the Univ. of California - Davis. The results showed that the enriched colony cages had similar production to standard battery cages. The cage-free system had problems with dirty eggs, poorer air quality, and increased bird mortality. The results of this study were clearly in favor of the enriched colony cages. Sound science recommended this system to improve bird welfare in large-scale operations.

A Need for Innovation

In my work I have worn many hats. My scientist hat is upset because the results of sound science are not being followed. However, my business hat is saying, we have new marching orders and the problems in cage-free housing must be solved in an economical manner. Eggs are a necessity and prices must be kept low because 25 percent of the US population is low income.

Recently I visited a cage-free house, which may have a solution for the dirty egg problem. It is now in the process of being patented. Air quality will be the biggest issue because providing hens with litter to scratch in, contributes to dusty air. One simple solution is to simply eliminate the litter. This will provide a high-density cage-free system with clean air. Unfortunately, it does not satisfy the behavioral need for a scratching surface and material for dust bathing.

I have visited a cage-free system that has no litter and where the air quality was good. One retailer I talked to had also visited one of these systems and really liked it. In this system, the hens have freedom to move and there are also secluded nest boxes where a hen can lay her egg behind a plastic curtain. This satisfies a highly motivated behavioral need to hide when laying eggs. Would this litter-free system satisfy the retailers and consumers? I predict that litter for scratching will still be required.

When I visited a poultry equipment show recently, I was amazed at the ingenuity of the equipment suppliers. They had created many novel new designs. Now they will need to innovate further and figure out how to keep the air clean and provide litter. One simple method would be to add a litter room to one of the already successful cage-free systems that houses birds on plastic grating. To keep the air clean, this room would have a separate ventilation system so the dust would not enter the main part of the house. This sounds expensive but there are economical ways to do it. As I write this article I have already made a few sketches. New marching orders have been received. We must figure out how to make an economical cage-free system that provides litter with clean air, clean eggs and lower bird mortality.