Impact of Corpus Luteum on in vitro Oocytes Recovery and Quality from Ovaries of Local Breeds of Cattle

Abstract

• In vitro embryo production is critical for accelerating genetic improvement in livestock. Nigerian cattle breeds were not exposed to assisted reproductive technology other than artificial insemination techniques. The efficiency of producing embryos using in vitro technologies rarely exceeds the 40% threshold, indicating that the proportion of oocytes that fail to develop after in vitro fertilization and culture is significant. The aim of this study was to determined oocytes collection and grading. Seventy-five bovine ovaries were collected from Sokoto Modern Abattoir and transported in a thermos container maintained at 37-38^oC and processed in the The ovaries were categorized based on the presence or absence of corpus luteum. The oocytes were recovered using aspiration technique. The oocytes transferred in minimum essential medium (MEM) and were graded using stereomicroscope based on cumulus investment and the nature of the cytoplasm into four grades: (I-IV). Greater numbers of oocytes were aspirated from ovaries without corpus luteum (CL- ovaries) 156 cumulus oocytes complex than those with corpus luteum (CL+ ovaries) (60 COCs). The CL- ovaries contributed higher normal oocytes (Grades I and II) than that of CL+ ovaries. It is highly recommended that ovaries without corpus luteum should be utilized for in vitro oocytes recovery and possible embryo production.