A Compassion Over Killing Report:
Animal Suffering in the Egg Industry
Reproductive Problems
Uterine
prolapsea condition causing the uterus to be pushed
outside of the hen's bodyis frequently seen in caged
hens, since, without a nest, the birds are exposed after egg
laying.(12) Dr. Susan Clubb
urges a ban on battery cages, claiming that because the birds
are bred to lay larger eggs in greater quantities, they are
more susceptible to uterine prolapse.(13)
Laying hens today lay an average of 240 to 250 eggs per year,
many more than the roughly 25 eggs their ancestors, Red Junglefowl,
lay in a year.(14) Selective
breeding for more productive hens has also led to the expression
of "genetic factors which increase death losses."(15)
In addition to laying larger eggs, the hens are also stressed
by the use of artificial lighting to prolong laying hours.
The hens' uterus cannot withstand the constant exercise of
egg-laying, exacerbated by the above factors, and uterine
prolapse often results.(16)