range of such technologies in order to prevent epidemic spread of disease in flocks and herds, which are particularly at risk when farmed under intense conditions (BBC, 2001). Even the therapeutic use of antibiotics to treat animals that have bacterial infections or are in danger of becoming infected seems not in itself to be controversial, except when antibiotics of medical importance to humans are employed.
The U.S. Food and Drug Administration (FDA) approved antibiotics as feed additives for farm animals in 1951. Their use since has been extended to fish farming, particularly with the global spread and dramatic increase of aquaculture in tanks and pond-like structures where antibiotics are used for prevention and control of disease rather than to enhance growth (NRC, 1999). The treated animals are found to grow more quickly and utilize feed more efficiently than animals on regular feed. At least 19 million pounds of antibiotics are used annually for subtherapeutic purposes in animal agriculture, and generally are added to feed and water (NRC, 1999). Some of these compounds, used on livestock, including penicillin, tetracycline, and fluoroquinolone used on livestock, also are prescribed to treat human illnesses, and the practice has been shown in a few instances to contribute to antibiotic resistance of human pathogens (Chiu et al., 2002; Molbak et al., 1999). It now is generally accepted in the scientific and medical communities that antibiotic resistance can be exacerbated by the widespread improper use of antibiotics. What remains controversial is whether agriculture contributes sufficiently to the problems associated with resistant pathogens to justify a complete curtailment of their use as growth promoters (DANMAP, 2000; Stephenson, 2002). A recent report from the National Research Council (NRC, 1999) failed to find a definitive link between the agricultural use of antibiotics in animal feed drinking water and antibiotic resistance of human pathogens. The report states, “The use of drugs in the food production industry is not without some problems and concerns, but does not appear to constitute an immediate public health concern.” Since that report was released, additional information, raising further concerns, has been released (Fey, 2000; Gorbach, 2001). Consequently, the practice remains under intense scrutiny and is opposed by some scientific and medical organizations.
Artificial insemination (AI), and the later, associated use of frozen semen, sire testing and sire selection are all part of a combinatorial approach to improve the genetic quality of farmed species. AI, when first introduced into agriculture,