Use of Antibiotics in Livestock and Human Health Concerns

Abstract

Animal feed additives have for many years constituted the largest and most controversial category of antimicrobial use. The primary concerns addressed have been the generation of antibiotic resistance in animal bacterial and the influence of such resistance on human health. Studies designed to shed light on the controversy generally have yielded information leading to ambiguous conclusions. A 1989 report from the National Academy of Sciences was the latest of a long collection of assessments that have been meant to provide expert guidance to regulatory authorities on this matter. The FDA has been trying for some time to determine whether a regulatory decision on existing products is warranted. After several decades of research directed at this question, most qualified study groups have reported a paucity of appropriate information necessary to judge the reality of a public health risk.

Growth and Development of Tetracycline-Resistant Chlamydia suis

“…The emergence of Tet r strains isolated from livestock raises the issue of antibiotic use in animal feeds (26). Chlortetracycline was the first feed additive, introduced in 1950, and has seen widespread use over the past 50 years (13). Sulfa drugs were also widely used as feed additives during the 1970s and early 1980s.…”

“…Livestock infections are most commonly treated with TET. In addition, livestock feed has been supplemented with TET for the past 50 years to ward off infections and promote growth (13). However, the introduction of antibiotics into animal feeds has encouraged the selection of resistant organisms (31).…”

Enterohemorrhagic Escherichia coli

“…Hay feeding has been shown to reduce colonization of E. coli O157:H7 and decrease prevalence from 52% to 18%, but this effect has not been consistently observed by other researchers (Callaway and DiezGonzalez, 2002). An estimated 50-70% of antibiotics used in the United States are given to farm animals (Gustafson, 1991) for three main reasons: (1) prophylactically, to prevent disease in flocks and herds; (2) to treat sick livestock; and (3) to improve digestion and utilization of feed, often resulting to improved weight gain (Sulakvelidze and Barrow, 2005). The use of antibiotics in livestock has become a major source of concern due to the possibility of contributing declining efficacy of antibiotics used to treat bacterial infections to humans .…”

Pesquisa de lasalocida y monensina en leche cruda de vacas lecheras suplementadas con estos ionóforos

“…Los aspectos involucrados al respecto son la generación de resistencia a antibióticos en bacterias de animales y la influencia que puede generar sobre la salud pública de las personas (Gustafson 1991). La industria de la leche ha utilizado por años ionóforos como aditivos en dosis que promueven una mejor eficiencia en la producción (Duffield y Bagg 2000).…”