Dissertation - Open Access
Doctor of Philosophy (PhD)
Corn is by far the most widely used cereal grain in the United States for poultry feeding. In addition to its high energy content, corn provides adequate amounts of the essential fatty acids for maximum rates of growth and egg production. Palatability and ample xanthophyll and provitamin A contents of fresh corn are some o the other contributing factors for its popularity in livestock feeding. The most serious limitation in the nutritional value of corn as well as other cereal grains lies in the fact that they are low in both quantity and quality of protein. It has been a common practice during the last two decades to supplement corn with soybean oil meal to increase the egg production efficiency for the laying hen. Although this method improves the quality of dietary protein, increasing the total protein content to meet the need of the bird for a few limiting amino acids can be considered uneconomical. It has been substantiated that the efficiency of protein utilization is reduced with increased protein intake. Furthermore, the increasing demand for plant protein supplements to be used directly by humans encourages researchers to reduce the needs for protein or to find an alternative protein source for animal production. Synthetic amino acids have been successfully used experimentally for determination of required levels of essential amino acids for non-ruminant animals. These compounds are potential substitutes for protein supplements to practical diets as well. With the addition of individual amino acids to a low protein diet (made up largely of corn) the pattern of these nutrients can be more closely controlled and thus wastage of excess amino acids minimized. Evidence has been reported showing that genetic variations related to strain differences may affect the amino acid requirements of the laying hen. The extent of differences among strains should be determined so as to feed individual strains according to their needs for more efficient conversion of dietary protein into egg protein. As the dietary protein is reduced to suboptimal levels, both the genetic variations and the balance of amino acids become more critical. The objectives of the studies reported herein were: (1) To compare the responses of various commercial laying strains to commonly known limiting amino acids in 12 and 10% protein diets. (2) To investigate the interrelationships between isoleucine and valine added to the 10% protein diet which is relatively high in leucine. (3) To determine valine requirements for egg production when the 10% protein diet made up largely of corn is used. (4) To study the effects of threonine and arginine supplementation of the 10% corn-soy layer diet. The parameters measured were egg production, egg weight, feed intake and efficiency, shell thickness, Haugh units, body weight change, mortality, plasma free amino acids and amino acid concentrations of egg albumen.
Library of Congress Subject Headings
Poultry -- Feeding and feeds
Amino acids in animal nutrition
South Dakota State University
Kashani, Ali B., "Effects of Strain on Response of Laying Hens to Low Protein Diets and Amino Acid Supplements" (1978). Electronic Theses and Dissertations. 5573.