Title

Optimization of oocyte recovery and embryo production from cows using ultrasound guided ovum pick up and IVF technology

Date of Completion

January 2005

Keywords

Biology, Animal Physiology|Agriculture, Animal Pathology

Degree

Ph.D.

Abstract

In this dissertation, the phenomenon of bovine ovarian follicular dynamics was studied to explore the possibility of stretching the output and usage of female gametes from live cows. Number of progeny produced from a genetically valuable cow is constrained by species specific physiological limitations. Newer approaches to overcome these limitations through retrieving ovarian follicular oocytes for further reproductive biotechnologies, are thus welcome. In the present work, protocols based on the use of gonadotropins and elimination of dominant follicle were developed to optimize the oocyte harvest from live cows. With an eye on industrial application where production of viable embryos or live calves from elite donors in a given time frame is important, a protocol was developed for weekly optimum embryo production from live cows using an OPU-IVF program. Oocytes harvested by OPU technique come from much smaller follicles and following forced maturation under artificial conditions, are unrealistically expected to attain the same degree of maturation as attained by the ovulatory oocyte. Hormonal protocols aimed at inducing partial in vivo maturation of oocytes apparently produced developmentally competent oocytes, thus improving the blastocyst development rates. Reflecting a typical OPU-IVF program, the study also looked at in vitro production of embryos using small number of oocytes. With the OPU-IVF system gaining wider acceptance and being considered as a serious alternative to the traditional MOET system of breeding, it is hoped that the present study would contribute to the understanding and application of this technique. ^