Exports of U.S. livestock and poultry products are important both to farmers and to the U.S. economy. In 2009, U.S. livestock and poultry exports were valued at more than $10 billion, accounting for about 12% of total global meat trade (estimated at nearly $87 billion in 2009). In recent years, however, some countries have considered or implemented changes to their agricultural and trade policies that could potentially affect U.S. livestock and poultry exports. One such change pertains to the use of antimicrobial drugs in animal production systems. Some U.S. trading partners and competitors, such as the European Union (EU), New Zealand, and South Korea, have implemented restrictions on the importation of livestock and poultry products grown with antimicrobial drugs. In the United States, legislation has been introduced that seeks to restrict the use of certain antimicrobial drugs for subtherapeutic or nontherapeutic purposes in food-producing animals. In the 112 th Congress, H.R. 965 and S. 1211 (Preservation of Antibiotics for Medical Treatment Act of 2011, PAMTA) seek to restrict the use of certain antimicrobial drugs for subtherapeutic or nontherapeutic purposes in food-producing animals. Most U.S. livestock and poultry producers are opposed to such restrictions because of concerns about animal welfare and food safety, as well as concerns about possible increases in production costs, among other reasons. This report is organized into three parts. First, it provides an overview of U.S. export markets for livestock and poultry products, and highlights key U.S. foreign trading partners. Second, it discusses policies in selected foreign markets that may restrict or limit the use of antimicrobial drugs in food animal production, including imports of animal products grown with these drugs. Third, it discusses some implications of these policies for U.S. livestock and poultry exports to selected foreign markets. Antimicrobials are used in food animal production as therapeutics (i.e., treatments), prophylactics (i.e., preventatives), and growth promoters. The U.S. Department of Agriculture (USDA) reports that antimicrobial use in the U.S. livestock and poultry sectors is a common practice. Available data suggest that antimicrobials are used in most phases of swine and poultry production and that usage has been increasing. Approximately 25%-30% of small cattle feedlot operations and about 60%-70% of larger feedlots use or are exposed to antimicrobials, most frequently through in-feed additives at feedlot operations. In December 2010, the U.S. Food and Drug Administration (FDA) reported sales and distribution of all approved uses of all dosage forms (e.g., injectable, oral, medicated feed) of the identified classes of actively marketed drugs in food-producing animals for 2009. These data have been widely cited as indicating that animal agriculture accounts for a large share of total use. Some industry groups, however, claim that FDA's estimate is overstated because, among other things, it includes ionophores, even though they claim that these drugs are not used in human medicine. When antimicrobials are used for therapeutic and prophylactic purposes, they help treat and prevent disease in exposed animals. When used at low levels in animal diets and feed for subtherapeutic (essentially nonmedical) purposes, antimicrobials help improve animal growth rates and feed efficiency, and also help reduce mortality and morbidity and may improve reproductive performance. Some studies show that higher growth rates from subtherapeutic antimicrobials have positively influenced producer incomes and resulted in higher per-animal net returns. Some studies suggest that large-scale confined animal operations are particularly dependent on the use of antimicrobial drugs in production. Growing scientific evidence shows, however, that certain bacteria are becoming increasingly resistant to these drugs, and that antimicrobial resistance may be transferred from animals to humans through the consumption or handling of meat that contains resistant bacteria. Public health experts also attribute such resistance to a number of other causes, such as overuse of antimicrobial drugs by medical professionals and their patients. Internationally, the issue of antimicrobial use in animal production and concerns about antimicrobial resistance continue to be actively reviewed by the World Health Organization (WHO) and the Food and Agriculture Organization (FAO) of the United Nations, as well as the World Organization for Animal Health (OIE). The United States is participating with other member countries in a Codex Alimentarius Commission Ad Hoc Intergovernmental Task Force on Antimicrobial Resistance aimed at helping to develop guidelines to assess human health risks associated with the presence of antimicrobial-resistant agents transmitted through food and feed. WHO first published global principles for the containment of antimicrobial resistance in food-producing animals in 2000. In the United States, legislation has been introduced in the last three Congresses seeking the phased elimination of nontherapeutic use in animals of "critical antimicrobial animal drugs" such as penicillin, tetracycline, macrolide, lincosamide, streptogramin, aminoglycoside, and sulfonamide, or other drugs that are used in humans to treat or prevent disease or infection. In the 112 th Congress, H.R. 965 and S. 1211 (Preservation of Antibiotics for Medical Treatment Act of 2011, PAMTA) seek to restrict the use of certain antimicrobial drugs for subtherapeutic or nontherapeutic purposes in food-producing animals. Some federal agency officials have indicated support for restricting the nontherapeutic use of antimicrobials. Other possible policy options that might limit the use of these drugs for growth promotion include assessing user fees, imposing targeted bans, or limiting new antimicrobials for human use only, among other options. See CRS Report R40739, Antibiotic Use in Agriculture: Background and Legislation , for background information on other recent actions on this issue in the United States. An understanding of the available information on country restrictions is often complicated by a divergence of policy objectives. Three aspects of antimicrobial use are regulated by U.S. authorities, and may also be regulated by most U.S. trading partners. More specifically, policies on antimicrobials may include restrictions on: 1. The use of certain antimicrobial drugs in producing livestock and poultry for meat consumption. As reported by FDA, scientific studies demonstrate a relationship between the use of antimicrobials in food-producing animals, antibiotic resistance in humans, and adverse health consequences. Studies also demonstrate that antimicrobial resistance among feedborne bacteria may cause prolonged duration of illness, and increased rates of bacteremia, hospitalization, and death. In the United States, FDA regulates these drugs and approves conditions of their use. 2. Residues of antimicrobial drugs remaining in meat tissues, which may exceed allowable standards, tolerance levels, or maximum residue levels. In some cases, even trace amounts of these drugs in meat and poultry products may pose a public health hazard for consumers who are allergic, or for some drugs that have been shown to cause other severe illnesses in some consumers. This problem is different from the problem of antimicrobial resistance in foodborne pathogens that may be transmitted through the meat and poultry products. In the United States, FDA sets tolerances or allowance limits in meat, and USDA's Food Safety and Inspection Service (FSIS) samples the products to assure compliance. 3. The use of certain antimicrobial washes and pathogen reduction treatments (PRTs) for treating meat during packing and processing of food products. These processes typically involve products that are used to treat animal carcasses by meat packers and processors, not drugs that are used in live animals. In the United States, products used in these processes are regulated by FSIS. This report focuses on available information on country restrictions regarding the first topic, namely, the use of certain antibiotics in feed for growth promotion (subtherapeutic or nontherapeutic) purposes in food-producing animals. World trade in livestock and poultry products totaled nearly $87 billion in 2009, with the United States accounting for 12% ($10.4 billion) of all global trade ( Table 1 ). Within product categories, in 2009, the United States supplied 31% ($3.8 billion) of all world trade in fresh, chilled and frozen poultry products; about 18% ($2.6 billion) of all fresh, chilled and frozen beef products; and 17% ($3.2 billion) of fresh, chilled and frozen pork products. The United States also supplied about 4% ($0.6 billion) of all world trade in processed livestock and poultry products. These statistics are based on country compilations of total reported imports, as reported in the Global Trade Atlas, and do not always comport with other country statistics, such as reported U.S. export data compiled by the U.S. Census Bureau. Following is an overview of U.S. export markets for beef, pork, and poultry products, highlighting key U.S. foreign trading partners and recent market shares for these importing countries. U.S. beef exports have been highly variable since 2000, primarily because of a significant decline in 2003-2004 due to concerns about U.S. cases of mad cow disease, among other trade issues. By 2008, U.S. beef exports had recovered somewhat and totaled nearly $3 billion worldwide, according to official U.S. export data ( Table 2 ). By volume, exports account for about 7% of total annual U.S. beef production. Fresh, chilled, and frozen beef accounts for the bulk of U.S. annual exports, comprising more than 90% of the total value of beef exports. Mexico and Canada are the leading importers of U.S. beef, receiving about two-thirds of annual U.S. exports ( Table 2 ). Several Southeast Asian countries also are among the leading international markets for U.S. beef, including Japan, Korea, Taiwan, and Hong Kong, accounting for about 30% of all exports in 2008. Exports to the European Union (EU) nations total about 3% annually.