In animal production systems, the concept of being able to alter the sex ratio and produce offspring of pre-determined sex is attractive and would be advantageous in improving genetic progress and cattle management plans. Production of single sex cattle population requires merging of several key reproductive biotechnologies i.e. oocyte recovery techniques, sperm separation and embryo transfer. Improvements in methods of oocyte recovery from ovaries of slaughtered cattle have been documented (Sharif et al. 1993, Azizah et al. 1998). Oocyte recoveries in pre-pubertal calves using laparoscopic method (Sharif et al. 1997) and laparotomy (Azizah et al. 2001) were carried out. Similarly many aspects on techniques of oocyte recovery from adult cattle donor using ultrasonography method (OPU) were documented (Sharif et al. 1999, Azizah et al. 2000, Sharif et al. 2000). So did, reports of successes of in vitro fertilization (IVF) techniques in Bos indicus crossbred cattle (Sharif et al. 1994) and birth of IVF calves locally (Sharif et al. 1995, 1996). Analysis and separation of bull sperm based on DNA content measurement using flow cytometry technique were also attempted with limited success (Sharif et al. 1998, 2000). These findings were in no way complete and the techniques obtained for all the phases were not optimized. This project is undertaken to further improve these techniques to allow efficient production of sexed semen, embryos and calves to exploit the potential of each sex for specific requirement of the cattle industry.

EXECUTIVE SUMMARY

Project Title:
Development of a biotechnology for the production of single sex cattle population based on in vitro embryo production, sex separation and transfer of bovine embryos

 

Several key areas of the production process of sex pre-selected spermatozoa and embryos such as configuration of the flow cytometer for sperm separation and embryo culture microenvironment will be studied.To achieve the project objectives, research will be conducted in three sub-projects. Each sub-project will undertake to improve each phases of the production system. These sub-projects are as follows. (1) Studies on follicular development of bovine oocyte donor and modification of oocyte recovery methods for optimum oocyte yield. (2) Flow separation of cattle spermatozoa for X- and Y-bearing chromosome with emphasis on alteration of configuration and modification of sampling technique for optimum sperm sorting. (3) Studies on modification of the microenvironment of bovine development in vitro, IVF of sex pre-selected spermatozoa and embryo transfer. It is expected that this project would aid in enhancing the modernization of approaches of cattle breeding delivery system. It would also provide development of human resources with new specializations and establishment of techniques for the production of single sex cattle population.

Period of the project : 3 Years (2001 - 2004)

Achievements

Progress/Achievements for year one

- Nill