Effect of ovarian cyclic status on in vitro embryo production in cattle.
BACKGROUND
The relationship between cyclic status of cattle ovaries on in vitro embryo development up to the blastocyst stage was investigated.


METHODS
Cattle ovaries were collected immediately after slaughter and divided into three categories based on their cyclic status, which included: 1. the presence of a large follicle (LF), 2. the presence of a corpus luteum (CL) and 3. ovaries without LF or CL (WLCF). Oocytes of these ovaries were obtained and used for in vitro maturation and fertilization. Presumptive zygotes were then cultured up to the blastocyst stage in synthetic oviductal fluid culture medium.


RESULTS
There were no significant differences between cleavage rates of the three groups. The rate of embryos in the compact morula stage for the CL group was 48.2% which was significantly higher than the related rate of the LF group (36.6%), but non-significantly higher than that of the ST group (45.7%). The highest blastocyst rate belonged to the CL group (54.6%) which was significantly greater than the WLCF group (32.9%) and non-significantly higher than the LF group (52.4%). There was no significant difference in blastocyst rates in the CL and LF groups.


CONCLUSIONS
Preselection of oocyte donor ovaries containing a CL or LF can be used as a feasible and non- invasive criterion to obtain the most competent oocytes capable of development to the blastocyst stage.
Department of Animal Science, Faculty of Agriculture, Islamic Azad University, Khorasgan Branch, Isfahan, Iran.
Akbar
A
Pirestani
Department of Reproduction and Development, Reproductive Biomedicine Center, Royan Institute for Animal Biotechnology, ACECR, Isfahan, Iran.
Sayyed Morteza
SM
Hosseini
Department of Reproduction and Development, Reproductive Biomedicine Center, Royan Institute for Animal Biotechnology, ACECR, Isfahan, Iran.
Mahdi
M
Hajian
Department of Animal Science, Marvdasht Branch, Islamic Azad University, Marvdasht, Iran.
Mohsen
M
Forouzanfar
Department of Reproduction and Development, Reproductive Biomedicine Center, Royan Institute for Animal Biotechnology, ACECR, Isfahan, Iran.
Fariba
F
Moulavi
Department of Reproduction and Development, Reproductive Biomedicine Center, Royan Institute for Animal Biotechnology, ACECR, Isfahan, Iran.
Parvaneh
P
Abedi
Department of Genetics, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran.
Hamid
H
Gourabi
Department of Embryology, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran.
Abdolhossein
A
Shahverdi
Department of Reproductive Imaging, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran ; Department of Andrology, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran.
Ahmad Vosough
AV
Taqi Dizaj
Department of Reproduction and Development, Reproductive Biomedicine Center, Royan Institute for Animal Biotechnology, ACECR, Isfahan, Iran.
Mohammad Hossein
MH
Nasr Esfahani
Cattle; Embryo; Estrous Cycle; Ovary