UNNATURAL | BROILER VS. EGG LAYER
Broiler chickens may develop several health issues as a result of selective breeding. Broiler chickens are bred to be very large to produce the most meat per animal. The large chickens cannot stand because their bodies grow too quickly for their legs. Therefore, they may become lame or suffer from broken legs.
Broiler chickens are also prone to heart attacks for the same reason, as the heart cannot support blood flow to the large body of the chicken. Another issue with selective breeding is the larger chickens have a more aggressive appetite. The broilers are feed restricted and this leads to behavioral issues in chronically hungry birds.
Broiler chickens may often get joint disorders because their legs cannot bear the heavy bodies. A Swedish study by SLU Skara (Swedish farming university) revealed that only 1/3 of studied broiler chickens that were about to be slaughtered were healthy.