Taco Bell announced this week that by the end of next year, they will be serving only cage free eggs in their breakfast menu items. This sounds like an excuse to raise prices, since cage free eggs command a premium price. Both McDonalds and Burger King have announced longer term plans to achieve this same goal. As we will see, this is basically a marketing decision.
While many people believe that cage free housing results in better animal welfare, actual scientific studies show this isn’t true. As we described earlier, there has been some significant research on this topic, by researchers from UC Davis, Michigan State, Iowa State and the USDA. They set up 3 housing trials: conventional cages (CC), expanded cages (EC) and cage free aviaries (AV), and carried out 3 parallel studies using one flock divided into 3 parts. They then repeated the entire experiment the next year with a new flock. The experiments and data collection took about 3 years, and resulted in eight papers in the journal Poultry Science. You can read the summary of the results here.
The designs of the three systems are shown in the housing system paper. The aviary system is a large new barn. “Hens were distributed in 6 colony rows with each row divided by wire mesh screens into 10 pens along the building length. Hens had access to 10.19 cm (4.01 in) of feeder space, 15.24 cm (6 in) of perch space, and 86.32 cm2 (13.38 in2) of nest space area.”
In general, the conventionally caged birds did the best in the experiment and the cage free aviaries the worst. The aviary birds cost about $1.85 more per pullet, and showed 5% lower productivity. The aviary hens had higher mortality (13.3%) compared to 4.8% in the conventional caged system. Aviary productivity fell to 10% below the conventional cages by the end of the cycle.
On the other hand, the hens in the aviary were found to have stronger bones and thus less broken bones than the CC and EC hens, and showed more hen-like behaviors. AV and EC hens cost a great deal more than CC hens did, AV was worse for worker health and safety, and AV was worse for emissions, and EC the best for ammonia emissions.
So, it depends on what measurements are important to you, but the higher mortality of AV hens and lower worker health and safety are certainly negative indicators. You can find an interactive chart of the results here.
Our conclusion is that for animal welfare, the conventional cage systems are actually better despite popular impressions to the contrary.
We were going to illustrate this article with photos of the Taco Bell breakfast items, but there is no nearby Taco Bell (within 20 miles) that serves breakfast. However, the reviews of these items have not been very good.
Food Science Institute 