[1] Three years prior to their approval, scientists were investigating a phenomenon in which chickens that were exposed to bacteria-rich manure displayed signs of better health compared to those that were not.
[2] Further research confirmed that antibiotic use improved chicken health, resulting in increased egg production, lower mortality rates, and reduced illness.
Consequently, farmers shifted from expensive animal proteins to comparatively inexpensive antibiotics and B12, as it enabled chickens to reach market weight faster and at a lower cost.
As of 2016, over 70% of FDA approved antibiotics were utilized in modern, high production poultry farms to prevent, control, and treat disease.
More specifically in 2012, the FDA speculated the most significant public health threat in regard to antimicrobial use in animals is the exposure of antimicrobial-resistant bacteria to humans.
[7] These statements have been challenged by the American meat industry lobbyists, who posit that antibiotics are used responsibly and judiciously in order to ensure effectiveness.
[12] Severity in mortality is coupled when exposed to high risk populations such as immunocompromised and elderly individuals in hospital and nursing home settings.
[13] National Antimicrobial Resistance Monitoring System's (NARMS) Enteric Bacteria program – Established in 1996, and represents a collaboration between the USDA, FDA, and CDC.
Seventeen total states are sampled every 5–6 years per livestock type, with the most recent surveys distributed to broiler farmers in 2006 and 2011.
[21] One obstacle to gathering more comprehensive data on the use of antibiotics in feed is the majority of the poultry industry utilizes vertical integration.
[25] The poultry industry also plays a large part in the United States economy, both in domestic purchasing and through international demand.
[27] Despite scientific evidence suggesting a strong association between antibiotic use in poultry and other livestock, agribusiness lobbies such as The National Chicken Council argue that there is not sufficient evidence to purport that there is a measurable impact to humans and shifts the blame of the problem of antibiotic resistance to overprescribing in the field of medicine.
As a reference, America spends about $101 billion per year for both governmental and biomedical industrial research, which is only 5% of total health expenditures.
For example, the 2013 Delivering Antimicrobial Transparency in Animals (DATA) Act proposed the enactment of policies to acquire more accurate documentation of antibiotic use in growth promotion by farmers, drug manufacturers, and the FDA.
[30] Antimicrobial Stewardship Programs (ASPs) serve as an example of systematic monitoring and analysis of data via interdisciplinary and multi-sectoral collaboration.
[33] As Guidance for Industry #213 has been voluntarily accepted, it will be a violation of the Federal Food, Drug, and Cosmetic Act to use antibiotics in livestock production for non-therapeutic purposes.
However, as there is now a requirement for veterinary oversight and approval for antibiotics use, there is leeway in the interpretation of non-therapeutic purposes dependent on the situation.
For example, per the FDA, "a veterinarian may determine, based on the client's production practices and history, that weaned beef calves arriving at a feedlot in bad weather after a lengthy transport are at risk to develop a bacterial respiratory infection.