Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)


Animal Science


Researchers, for several years, have tried various methods of retarding the onset of egg production in chickens. Some reports have shown that a delay in sexual maturity is beneficial. When comparing restricted pullets to unrestricted control groups, these reports reveal economic advantages of restriction in that restricted pullets have lower total feed costs, improved egg size, improved total egg production and a lower percentage of mortality during the production cycle. Other research has accomplished restriction with no resulting advantages. These discrepancies may be due, in part, to inaccurate means by which the results of restriction have been measured. Confinement rearing of replacement stock offers a greater chance for altering the growing environment than was possible when pullets were reared outdoors under range conditions. A review is made of several methods of retarding sexual maturity in chickens. Studies were conducted using iodine in the form of potassium iodide and chlormadinone acetate. Resulting data were analyzed to test the effectiveness of these compounds in suppressing sexual maturity when fed to egg-type pullets.

Library of Congress Subject Headings

Poultry -- Feeding and feeds
Poultry -- Breeding



Number of Pages



South Dakota State University