Antibiotics are sprayed onto fruit trees and other food-bearing plants to control disease. In addition, antibiotics are added to feed stocks to prevent disease and improve the growth rate among food-producing animals. Scientists have discovered a link between agricultural use of antibiotics, particularly in animal feed, and the increase of food-borne infections in humans who consume products derived from these animals. Resistant bacteria present in animals can survive the slaughtering and meat-packaging process. Undercooked meat will harbor these bacteria and when eaten can cause illness in humans. To further complicate the situation, the antibiotics used to treat humans made ill by infections may be similar to those used routinely in animals, rendering the medication less effective.