As published in a study for Poultry Science three different chicken strains were compared from 1957, 1978, and a commercial Ross 308 strains (2005) at the University of Alberta. Each of the chicken strains was fed the same feed under the same conditions, and their respective weights were measured at 56 days of age. Part of their conclusion was that: "From 1957 to 2005, broiler growth increased by over 400%," which means that over the last fifty years, the poultry producers have figured out how to through genetic modification increase the size of their chickens over 400%, which is simply stunning, through selective breeding and genetic genius. To the consumer of chicken, this means that the price of chicken is cheaper, in fact significantly cheaper than what it would be if this unprecedented growth had not occurred, and for the producer of poultry this means significantly less money spent on chickens per the yield of chicken meat and a more efficient utilization of space for the farming of chickens themselves.
The poultry industry is big business so that commercially bred poultry for mass production are virtually in all cases not free-range chickens but bred instead inside long, low, and dark sheds which are filled with chickens and more chickens that have difficulty in even walking due to lack of space and the disparity of the weight of their breast meat and overall body to their legs. Under these conditions the main concern for poultry producers is not the comfort of the chickens themselves, but the constant assurance that there is no imminent danger of a contagious chicken-borne disease that would decimate the population of the chickens, consequently most poultry producers make it a routine practice to add antibiotics to their animal feed so as to assure themselves of the continual good health of their product.
For poultry producers antibiotics are that "perfect storm" of correct animal feed because not only does the antibiotic control or reduce infectious diseases to the birds themselves, it also produces increased weight gain for chickens, so that this type of dual benefit seems like a gift from the gods. However, like anything that is routinely used to fight or to stave off diseases, bacteria itself will develop over time resistance to these antibiotics, to which when inadvertently transferred over to humans, endangers the safety of human beings because of their resistance to typical antibiotic drugs which could result in extensive hospitalization or even death.
Not too surprisingly, poultry producers are reluctant to correct or to change the very things that have allowed them to make massive profits over the years as well as providing to consumers a product that is both cost-efficient and extremely popular. Consequently, the only hope of making meaningful change when it comes down to antibiotics in our poultry feed is transparency along with specific rules and regulations passed by the FDA that would apply equally to all. However, pharmaceutical companies and large agribusinesses along with the respective logistical chain organizations that are utilized to provide us with cheap poultry have a vested interest in keeping things the way that they currently are, but this type of short-sighted thinking does a grand disservice to the public at large and puts ultimately human life and health at risk under the banner that the lust for money rules all.