Abstract/Summary

Most environmental concerns associated with livestock farms focus on nutrients (nitrogen, phosphorus) that impair the health of aquatic systems or on pathogens that may lead to food- or water-borne disease. In recent years, however, other potential contaminants are becoming of concern. Hormones (oestrogens, androgens, progesterone and various synthetic hormones) contained in livestock manure have generated wide interest because of their endocrine disrupting effects (Lange et al., 2002; Hanselman et al., 2003; Lorenzen et al., 2004). Similarly, the extensive use of antibiotics in animal agriculture and the development of antibiotic-resistant bacteria are cause for increasing concern. Livestock operations are often cited as a reservoir for resistant bacteria and antibiotic resistance genes (Chee-Sanford et al., 2001; Smith et al., 2004; Sawant et al., 2007; McKinney et al., 2010), and antibiotic use has implications for both animal and human health. This chapter will focus on these emerging contaminants in livestock manure.