These short grasses can have roots that extend 1 m (about 3 ft) deep. The height of grass correlates with the amount of rainfall it receives. Grasslands receive about 500 to 900 mm of rain per year compared to deserts, which receive less than 300 mm and tropical forests, which receive more than 2,000 mm. While temperatures are often extreme in some grasslands, the average temperatures are about -20Â°C to 30Â°C.
The use of antimicrobials has been linked to the rise of resistance in every drug and species where it has been studied, including humans and livestock. However, the role of antibiotic use in food animals â in contrast to the use of antibiotics in humans â in the rise of resistant infections in humans is in dispute.
Antibiotics are added to the animal feed or drinking water of cattle, hogs, poultry and other food-producing animals to help them gain weight faster or use less food to gain weight. Because all uses of antimicrobial drugs, in both humans and animals, contribute to the development of antimicrobial resistance, it is important to use these drugs only when medically necessary. Governments around the world consider antimicrobial-resistant bacteria a major threat to public health.