NUTRIENT REQUIREMENTS FOR CANADIAN YORKSHIRE SWINE: I. A STUDY OF THE U.S. N.R.C. (1953) STANDARDS

Abstract

A co-operative nutrition project involving eight institutions across Canada was undertaken in order to test some of the swine feeding standards in the 1953 revision of "Nutrient Requirements for Swine". Four stations (University of British Columbia, University of Alberta, University of Manitoba, and the Experimental Farm, Nappan, N.S.) conducted swine feeding trials. Four rations were fed at each station: A—a centrally formulated barley ration based on the N.R.C. requirements for protein, Ca, P, vitamins A and D; B—a formula chosen by the co-operator; C—a ration based on the standards but employing barley plus oats as the basal grains, all ingredients being from local supplies; D—similar to ration C, but with barley plus wheat as the basal grains.All feeds were analysed for crude protein, crude fibre, ether extract, ash, energy, Ca, P, weight/quart, riboflavin, niacin, choline and pantothenic acid. Carcasses were graded according to commercial grades and scored in detail according to Canadian Advanced Registry standards.Approximately normal gains and feed efficiencies were obtained during the growing period (40–110 lb.) despite riboflavin, T.D.N. and pantothenic acid levels below the standards. Similar results occurred in the finishing period (110–200 lb.) but carcass quality proved to be unsatisfactory. It is suggested that the gains during the finishing period represented too much fattening in relation to skeletal and muscle development.