Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Poultry Science


The protein requirement of the laying hen encompasses a problem of great importance to the nutritionist. With the discovery of amino acids, which are commonly referred to as "the building blocks of protein," it was soon evident that the fowl had a requirement primarily for amino acids, not protein. It has been difficult to establish the exact amino acid requirements of each species and age group. To overcome this difficulty, feed formulae for laying hens as well as other groups of fowl have been designed to provide a surplus of protein and thus amino acids from a wide variety of sources. In general, this practice has met with success. Today, however, we are faced with economic restraints which compel the feed manufacturer to exclude all unnecessary ingredients from rations. In view of the high cost of protein supplementation, it has been deemed necessary to restrict protein levels to the bare minimum essential for the most efficient production. If protein supplements can be fortified with amino acids from a synthetic source to balance the amino acid content of the feed to the amino acid requirement of the hen, it may be possible to reduce the cost of egg production. Soybean meal, the most commonly used protein supplement in laying hen diets, is ·deficient in the amino acid methionine. These experiments were undertaken to compare a typical corn-soy type diet which was considered adequate in both protein and methionine to a similar corn-soy type diet which was lower in protein but supplemented with synthetic methionine.

Library of Congress Subject Headings

Poultry -- Feeding and feeds

South Dakota State University Theses



Number of Pages



South Dakota State University