Excessive use of antibiotics in livestock can lead to:

The correct answer is: All of the above.

Excessive use of antibiotics in livestock can lead to antimicrobial resistance, food safety concerns, and environmental contamination.

• Antimicrobial resistance is the ability of a microorganism to withstand the effects of medication that once could successfully treat the microbe. When bacteria become resistant to antibiotics, they are more difficult to treat, and can cause more serious infections.
• Food safety concerns arise when bacteria that are resistant to antibiotics are present in food. These bacteria can cause food poisoning in humans, and can be difficult to treat.
• Environmental contamination can occur when antibiotics are used in livestock production. Antibiotics can be excreted in animal waste, and can contaminate soil and water. This can lead to the development of antibiotic-resistant bacteria in the environment.

It is important to use antibiotics judiciously in livestock production to prevent the development of antimicrobial resistance. Antibiotics should only be used when necessary, and should be used for the shortest possible duration.