On individual told me he never purchases organic food because he believes non-organic food is safer. Virtually no one dies of pesticides, but the absence of pesticides allows the growth of other microbials that makes food less safe. The latter part of that sentence may not be exactly right, but it was something like that.
A conversation I can better attest to regarded the welfare of laying hens. We typically think of organic eggs coming from happier chickens, as the organic standards have several welfare requirements, such as access to some free-range. Yet, one of the world's foremost authority on hen welfare told me he/she would never purchase organic eggs because he/she believes it to possess low welfare for the birds. I asked him/her to elaborate.
The major welfare problem with organic eggs is the low provision of health care. Organic producers cannot use synthetic amino acids, and this causes the hens to experience nutritional deficiencies, especially on small farms who possess a less sophisticated understanding of nutrition. Second, the large group sizes results in an enormous amount of inter-bird injury. Third, antibiotics are prohibited under organic standards. A hen who is sick and deserving of antibiotics would have to be pulled from the flock to receive the antibiotics, and her eggs sold on the traditional market at a much lower price. Faced with these incentives, farmers allow chickens to either die or experience sickness close to death before they provide the hens with the antibiotics they need.
Consequently, while layers may have more space under an organic system, they experience much greater mortality rates. What good is more space to a layer if she dies?
There are variations of egg production between the cage and organic system. I consulted individuals at the conference to better understand the mortality rages among these systems, and here is what I found.
Egg System Mortality Rate (% hens that die between pullets and being deemed spent)
Cage 3-5%
Enriched Cage 2%
Barn / Aviary 6-8%
Free-Range* 14%
Organic 20-28%
*free-range system here refers to an outdoor system with minimal barn / shelter provision
Comment added by Bailey on 2/13/09...
I recently talked with a very large organic egg producer and he suggested these numbers
Egg System Mortality Rate (% hens that die between pullets and being deemed spent)
Cage 2-3%
Barn / Aviary 6-8%
Organic 10-12%
Cage 2-3%
Barn / Aviary 6-8%
Organic 10-12%