In recent years, livestock production systems, especially those common in intensive swine farming has been utilizing zinc oxide (ZnO) and copper sulfate (CuSO4) as growth promoters (Salyer et al., 2004).
In recent years, livestock production systems, especiallythose common in intensive swine farming has beenutilizing zinc oxide (ZnO) and copper sulfate (CuSO4)as growth promoters (Salyer et al., 2004).