Since animals have been domesticated, they have been very instrumental in providing humans with a myriad of benefits in multiple areas such as agriculture, medicine and industry ( transgenic animals). Today, animals and their products are used for almost everything, from food to clothing to the products we use every day. Some argue that animals should not be used as much as they are used; however the use of domesticated animals pushed humans from a nomadic species to a more civilized people. The domestication of animals was a keynote of the beginning of agriculture as a whole, which led to industrialization and progress as humans. Pets play a prominent role in our society today and in the future. Domestic animals, such as livestock and poultry, are significant in the daily lives of people around the world. In developing countries, they play a key role as labor for farmers for whom purchasing an expensive tractor or sprayer is not financially viable (The Importance of Livestock). From a nutritional point of view, “animal-based foods can provide a variety of micronutrients that are difficult to obtain in adequate quantities from plant-based foods alone” (Allen and Murphy 3932S). Therefore, animals represent a “link” in nutrient cycles because they are able to eat plants and provide us not only with some plant nutrients, which we would normally not be able to take advantage of on our own, but they also give us their own animal nutrients (The importance of livestock). Animal-based foods also provide higher levels of micronutrients at lower consumption than plant-based foods (Allen and Murphy 3933S). Animals also return some nutrients to the soil through defecation or d...... middle of paper ......Application studies in human patients." Neurology 69.24 (2007): S28-32. Web."The Importance of Livestock." CGIAR News. Consultative Group on International Agricultural Research, 1997. Web. 11 March 2014. Kato, Tasuku, Hisao Kuroda, and Hideo Nakasone. “Characteristics of Nutrient Runoff from an Agricultural Watershed with Intensive Livestock Production.” Journal of Hydrology 368.1-4 (2009): Web.Murphy, Suzanne P. and Lindsay H. Allen. “Nutritional Importance of Animal-Derived Foods.” Redwan, El-Rashdy M. “Animal-Derived Pharmaceutical Proteins.” Journal of Immunoassay and Immunochemistry 30.3 (2009): 262-90 Web.Roberts, Beth “Animals in Industry.” Web. “Transgenic Animals: Their Benefits to Human Welfare.”. 2014.