Microorganisms are naturally present in the digestive systems of animals. Some microbes aid digestion, others can potentially cause disease. Through biotechnology, scientists are trying to ensure animals have the healthiest possible digestive system. Prebiotics is the use of feed compounds to promote the growth of helpful bacteria in the intestine. Both prebiotics and probiotics reduce the strength of disease-causing bacteria.
Hormones are chemicals secreted by the animal's glands.
These chemicals act as switches, which start body processes. Livestock growth hormone helps cows and pigs more efficiently convert feed nutrients to meat or milk. Currently, growth hormone is injected directly into animals. New areas of research involve use of specific amino acids to stimulate the natural release of growth hormone, to improve growth and meat production in cattle. The ability to transfer DNA from one species to another offers the promise of improving livestock metabolism.