Hen Housing and Bird Welfare

A commercial-scale study of housing alternatives for laying hens is being conducted by the Coalition for Sustainable Egg Supply in the United States. The coalition is studying each housing system closely and evaluating the viability of the many variables of each, including environmental impact, food safety, worker safety, animal health and well-being, and food affordability.

According to the coalition, the research will aid food companies and other organizations in making purchasing decisions that are ethically grounded, scientifically verified and economically viable.

Earlier this year, Dr. Janice Siegford from Michigan State University (MSU) shared some of the preliminary results at the sixth Annual Animal Research Symposium at the University of Guelph.

Siegford and her team are studying hen welfare and behaviour in aviary systems, in co-operation with research teams from the University of California and Iowa State University, evaluating all three systems for environmental quality, human health, food safety and economics. “So we’re really trying to do a whole system analysis so that the data we get out of this can be put into context,” says Siegford.

The need for this research stems from a combination of public pressure and regulatory changes: in some U.S. states, new regulations dictate that laying hens must have room to stand and stretch their wings without touching the cage.

Since conventional cages are no longer an option, producers are left deciding which system is best to transition into. Research has been limited on the subject, and more often than not, focused on conventional systems.

“Do these alternative systems actually improve welfare?” asks Siegford. “We’re giving them these things, but are we giving them in a way that’s meaningful to the hen?”

No matter which factors you consider – economics, welfare or food safety – research shows that no system is perfect. “We haven’t got it perfect yet, for sure,” Siegford says. “With the enriched system, there are a lot of nice features in terms of providing the hens with the different kinds of environmental features that they might like, keeping things like cannibalism to a minimum, keeping disease transmission on a low scale, etc.”

She points out that the enriched system still preserves some of the good aspects of the conventional system; for example, hens still drop eggs into clean nests. Rollout belts are used so that eggs stay clean and there is not as much potential for breakage or egg loss. Droppings are carried away on belts and kept contained, so from an environmental and food safety standpoint, they’re very clean.

“And you still have pretty good feed efficiency and feed conversion,” says Siegford. “One of the issues with hens when you move to some of the other housing systems, is that if you put fewer hens in a building, they’re generating less body heat and then you have to feed them more to increase heat or pump more heat into the building.

“With the enriched systems, you can still have a fairly large number of hens per square foot, so you still avoid some of those problems. If you’ve got hens that are constantly outside of their thermal-neutral zone, then it becomes a welfare issue.”

When it comes to hen welfare, though, the best option for laying hens is dependent on their strain. “If you have hens that are fairly mellow and not likely to pick on each other, then putting them in an aviary system does give them a lot of behavioural freedom. They can make a lot of choices, have a lot of control over how they spend their day, and then they’re not likely to suffer being picked on or pecked at by other hens.”

Unfortunately, though, a lot of the high-producing strains do pick on one another. “You can’t just say that the aviary’s universally better for welfare for all hens because cannibalism is obviously really an ugly problem,” says Siegford.

“Sometimes you give chickens the freedom of choice and they do some pretty awful things to each other.”

Another welfare issue with hens is bone breakage. Regardless of which system you use, bone breakage will always be an issue. The same is true with feather loss, which occurs around their necks from feeding in caged systems. In the non-caged and outdoor free-range systems, feather loss problems are a result of pecking.

As Siegford and her team at MSU reviewed the preliminary data, they were most surprised by the perching behaviour of the hens. Although the aviaries provided perches on all three levels, their usage was not as evenly distributed as the researchers expected.

“When you look at those hens perching at night, even though within each level the perches are six inches above the floor, they still cram into the top level to perch at night,” says Siegford. “You see the most birds up top, an intermediate number of birds in the middle and very few birds on that bottom level.

“So even though we’re providing them in the furnished cages, we still haven’t gotten the perches right yet,” she continues.

Siegford credits producers and manufacturers with being innovative, though. “Most of them are making an effort to provide hens with things like perches, nesting areas, litter potentially for dust bathing, things of that nature, that hens have demonstrated to be strongly motivated to perform or that do substantially improve welfare. But it’s just not that simple.”

IN CONCLUSION

As producers transition from conventional to new alternative systems, it is important to know that considerable liabilities still exist in terms of economic efficiency, hen welfare and biosecurity, and it cannot be assumed that non-cage systems will improve hen welfare to a level that is acceptable to both producers and consumers.

Although enriched systems appear to be the best choice, the jury is still out. While the data has not yet been analyzed, Siegford’s team has finished collecting information from the second flock and its final report should be available sometime in 2014.