Life Sciences Commons^™

Intracellular Lipids In Bos Indicus And Box Taurus Oocytes, Casey Bryant Ballard

LSU Master's Theses

It has been proposed that Bos indicus when compared with Bos taurus embryos are more sensitive to cryopreservation procedures due to higher intracellular lipid content of the embryos. With cyropreservation of Bos indicus embryos increasing for export, it is essential to improve the viability of these cryopreserved embryos. In Experiment I, M-II oocytes from mice, pigs and cows were subjected to two different procedures to evaluate lipid content. The lipid content present in pig oocytes was significantly (P<0.05) higher when compared with mouse and cow oocytes. Pig oocytes had a lower settling point in the sucrose buoyant density gradient and higher Nile Red units, which indicated higher lipids present in the oocytes. In Experiment II, it was determined that M-II oocytes aspirated from superstimulated Brahman donors were significantly higher (P<0.05) in lipid content compared with English breed donors. The lipid content present in Brahman oocytes was higher when compared with English breeds when tested with a sucrose buoyant density gradient and Nile Red staining. In addition, donor females with higher body condition scores were significantly (P<0.05) higher in oocyte lipid content when compared with donor females of lower body condition scores. Furthermore, animal body condition scores, cholesterol and triglyceride levels prior to oocyte aspiration may be indicators of intracellular lipids in the oocytes and embryos. To our knowledge, this is the first report that evaluated intracellular lipid content of M-II oocytes of different beef breed types using a sucrose buoyant density gradient and Nile Red staining.