Document Type

Thesis - Open Access

Award Date


Degree Name

Doctor of Philosophy (PhD)

Department / School

Animal Science


Low protein diets were formulated for experiments with laying hens and turkey poults. The diets were supplemented with equal amounts of protein and different feedstuffs while maintaining equal calculated levels of selected amino acids. Single trails were also reported for factorially applied amino acid supplements to turkey starter and cage-layer diets. The three-year studies indicated that a typical corn-soy layer diet diluted with glucose monohydrate to 9.4 percent protein was deficient in methionine, lysine and tryptophan. Attempts to further improve the rate of egg production by additional supplements of arginine, isoleucine, valine, or diammonium citrate were not successful. The low protein diet for layers was then supplemented with3 or 6 percentage equivalents for protein from common feedstuffs in an effort to improve egg production from approximately 55 percent, on a hen-day basis, to 65 percent or better for 10 months of production. It was apparent that the 9.4 percent protein layer diet was deficient in a substance which could be supplied by several feedstuffs. Supplements of three percentage equivalents of protein from yellow corn, spring wheat, barley, soybean meal, soybean protein and fish meal, soybean protein and fish meal elicited a response in production. Supplements of 6 percentage equivalents of protein from soybean meal, soybean protein or a mixture consisting of a 40:60 ratio of protein from corn and soybean meal did not further improve production. Supplements of 3 percentage equivalents of protein from hydrolyzed feather meal, oats, meat and bone scraps, or milo or of nf-180 did not stimulate marked improvement over that obtained from the 9.4 percent protein amino acid supplemented basal diet. Studies were also made with turkey poults fed low protein starter diets supplemented with amino acids to 40, 60, or 80 percent of the feeding standard proposed by Dunkelgod et al. (1961). Growth rates of poults fed to four weeks of age on 20 percent protein diets were slower for poults fed diets containing 13 percent protein equivalents from hydrolyzed blood meal, corn gluten or meat and bone scraps than were growth rates of poults fed diets with soybean mean, safflower meal or fish meal as the supplementing the diet with amino acids to 60 percent of the standard. Further supplements to 80 percent of the standard did not affect growth rates. Studies were also made with turkey poults which involved factorial application of treatments. The 20 percent protein diet was supplemented with amino acids to 100 percent of the amount calculated for the 28 percent protein corn-soy control diet. The results of the factorial expressed as effects means of body weight indicated that the effects indicate that methionine, lysine, and tryptophan were deficient in the 20 percent protein corn-soy starter diet. Further indications of a deficiency of valine and detrimental effect of excess isoleucine were observed. A similar type of study was made with a 9.4 percent protein diet for caged layers. Supplements of methionine, lysine, valine and inositol were used. The results indicated that variation between groups was not consistently correlated with time or with the four factors in the test. The effect means of hen-day egg production may not have been an adequate measure of response to dietary supplements in this limited study. Free amino acid levels in serum from turkey poults and electrophoretic patterns of egg protein and plasma protein on polyacrylamide gel were found to be poor indicators of the nutritional adequacy of the diets used in this study. Free amino acid levels were not consistent among birds treated alike. Serum protein electrophoretic patterns were essentially the same for all hens and poults regardless of the diet being fed.

Library of Congress Subject Headings

Poultry -- Feeding and feeds

Amino acids in animal nutition



Number of Pages



South Dakota State University