Owen, B.D.2013-09-042013-09-041967-03March 1967http://hdl.handle.net/10388/5747A fundamental principle recognized in all studies of nutritive requirements was set forth by Haecker in these words as quoted by Maynard and Loosli (40): "In order to determine the actual net nutrients required to produce a given animal product, the composition of the product should be known, as well as the composition and the available nutrients in food which is to be fed for its production, so that the nutrients in the ration might be provided in the proportions needed by the animal. At the present time, feed grain composition data of Canadian origin is seriously lacking, and it is necessary, therefore, to rely on analytical data from elsewhere, mainly the U.S.A. There is evidence available (28, 48, 52) indicating that levels of certain nutrients in Western Canadian grains differ appreciably from those reported by the National Research Council (U.S.). There is evidence also for variations attributable to soil type and climate (28, 43, 66, 52).Thesis