title: An historical perspective: the development of methods for assessing nutrient requirements.
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D000829:Animals, Domestic / Q000378:metabolism*; D002417:Cattle; D005060:Europe; D049672:History, 19th Century; D049673:History, 20th Century; D009751:Nutritional Requirements; D014481:United States