title: Serum copper levels of cattle in El Salvador.
mesh_terms: D000818:Animals; D002417:Cattle / Q000097:blood*; D002418:Cattle Diseases / Q000175:diagnosis; D003124:Colorimetry; D003300:Copper / Q000097:blood* / Q000172:deficiency; D004544:El Salvador; D012621:Seasons
chemical_list: D003300:Copper