Identifier

etd-11102004-140641

Degree

Doctor of Philosophy (PhD)

Department

Animal Science (Animal, Dairy, and Poultry Sciences)

Document Type

Dissertation

Abstract

Calving rates are significantly reduced following in vitro production of embryos. Thus, if a technique could be developed that would increase calving rates by as little as one viable offspring, significant research advances could be made. Therefore, in a series of experiments, the efficiency and quality of culturing IVP bovine embryos in the amnion of a domestic chicken egg was tested. In Experiment I, by culturing IVP bovine embryos in the chick amnion (day 4 to 7 of incubation) it was discovered that there was no significant difference in blastocyst rates compared with controls. In Experiment II, it was shown that nuclear transfer bovine embryos cultured in the chick amnion reached the blastocyst stage at rates equal to controls and were capable of producing pregnancies following transplantation into recipient females. In a subsequent experiment, a method of naturally improving the chick embryo co-culture (CEC) system was explored by treating the developing chick embryo with prostaglandin E2 (PGE2) or prostaglandin F (PGF). It was determined that treatment with PGE2 increased angiogenesis within the developing chicken egg, while treatment with PGF decreased angiogenesis. When bovine embryos were cultured in PGE2-treated chicks, developmental rates were not increased. In Experiment IV, chick amniotic fluid (CAF) was evaluated as a media supplement to the control culture system. Although replacing fetal bovine serum (FBS) with CAF resulted in significantly fewer blastocysts on day 7 of culture, there were no significant differences in the number of grade 1 embryos between the two treatments. This finding was important because it demonstrated an ability to culture IVP bovine embryos in the absence of FBS, a medium component that has been implicated in numerous fetal and calf abnormalities. Another experiment was designed to develop a method of culturing cells derived from the chick embryo and surrounding amniotic membrane for later use as a co-culture system for bovine IVP embryos. In the final experiment, using a novel method to detect apoptotic cells, it was determined that CEC did not alter the number of apoptotic cells in the embryo when compared with in vivo-derived or in vitro-cultured bovine embryos.

Date

2004

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Robert Godke

Share

COinS