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ARS Home » Research » Publications at this Location » Publication #71896
Title: MINERAL METABOLISM IN AVIAN EMBRYOS

Author
item Richards, Mark
item PACKARD, MARY - COLORADO STATE UNIVERSITY

Submitted to: Poultry Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/18/1996
Publication Date: N/A
Citation: N/A

Interpretive Summary: A variety of minerals are important for the normal growth and development of avian embryos. Without an appropriate supply, the embryo ceases to grow properly and defects develop in virtually all of the major organs of the body. In extreme cases, the embryo dies. Similar outcomes are observed when too much of a particular mineral is given to the developing embryo. Thus, a precisely regulated supply of each required mineral is necessary for successful embryonic development and hatching of the chick. This manuscript summarizes current knowledge about the mineral content of avian eggs and it also explores the strategies employed by the developing avian embryo and its tissues to acquire and assimilate minerals required for its development inside of the egg. The findings reported here have important implications in several areas. Understanding the mineral composition of eggs gives insight into the nutritional value of eggs consumed by humans. Also, the information in this report is useful in understanding the mineral requirements of the laying hen in order to ensure successful production of healthy and normal offspring. Finally, the information in this report offers researchers new ideas about the basic biochemical processes involved mineral metabolism during avian embryonic growth and development.

Technical Abstract: Mineral metabolism in the developing avian embryo starts with the formation of the egg and the mineral deposits contained within it. The site of deposition of each mineral and its chemical form dictate how it will be mobilized and assimilated by the tissues of the embryo. Mobilization and transepithelial transport of egg mineral deposits are mediated by the actions of the extra-embryonic membranes, principally the yolk sac and the chorioallantois. Transport of minerals in blood involves metal-binding, plasma proteins synthesized initially by the yolk sac and later by the liver of the embryo. Once in embryonic circulation, minerals are transported to such tissues as the liver, which serves as a transient storage site for trace minerals, and bone, which is the major site for calcium accumulation in the embryo. Thus, embryonic mineral homeostasis is established through the coordinated actions of the yolk sac, the chorioallantois, embryonic circulation, and tissues of the embryo, the functions of which are subject to developmental regulation.