Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)


Animal Science


One of the urgent tasks facing agricultural scientists throughout the world is that of supplying sufficient food of adequate quality to the ever-increasing human population. The problem is not only that of supplying calories but also providing adequate quantity and quality of protein. Ruminant animals have the ability to convert much plant energy, not utilizable or having low availability for man, and nonprotein nitrogen products into body tissues. Ruminant animals, therefore, can have a very important role in providing food for the human population. The most widely used nonprotein nitrogen compounds urea. The process of building amino acids into body protein from nonprotein nitrogen compounds is accomplished through the symbiotic relationship of the rumen microorganisms. The efficiency of urea utilization may be affected by several factors. Among these are level and source of energy, level and source of protein, concentration of minerals, vitamins and perhaps other factors in the diet. Although lower feed costs are generally obtained as a result of substituting nonprotein nitrogen compounds for preformed protein, animal performance has often been lower or inconsistent. This has prompted investigations toward the improvement of urea utilization. Body protein is made of amino acids. By studying amino acid concentrations in the blood, nutritionists have been able to obtain information on dietary deficiencies. Some experiments have shown that the sulfur containing amino acids are the first limiting ones in ruminants receiving diets containing urea. Experimentation has also shown that ruminants through their microorganisms can also utilize inorganic sulfur in the synthesis of sulfur-containing amino acids. Much attention has been devoted to the need for sulfur supplementation and the availability from various sources when feeding diets where nonprotein nitrogen makes up the major portion of the supplemental protein. The objective of this research was to study the effects of calcium sulfate, sodium sulfate and methionine hydroxy analogue calcium in practical ruminant diets. Two feeding trials were conducted with weight gains, feed consumption, feed utilization and carcass data used as measures of performance.

Library of Congress Subject Headings

Lambs -- Feeding and feeds

Urea as feed



Number of Pages



South Dakota State University