Online Extra: Table: Tale of Two Cows

Organic and conventional cows have one thing in common: They produce milk
  Conventional Cow Organic Cow
Name An ID number Daisy, Peaches, etc.
Average Life Span 4 to 5 years 10+ years
Average Daily Milk Output 54 pounds 43+ pounds*
Primary Diet Silage, hay, and commercial feed that can include corn, barley, fishmeal, potato waste Grass from pastureland and hay, with some organic feed
Additives/Medicines Bioengineered growth hormones, antibiotics Occasional vitamins and herbs
Living Quarters Dairy "feed lots" or barns, sometimes in stalls where they are machine milked Spacious barns or stalls, lots of outdoor time
Breeding Artificial insemination Mating with bulls
*Organic output can be 20% less, in part because farmers often don't push the animals as hard
Source: U.S. Agriculture Dept., BusinessWeek
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