Embryo transfer technology (ETT) in cattle and buffalo in India: A review

Abstract

ETT is one of the most important reproductive biotechnologies where male and female genetic material could be utilized for the faster improvement of livestock. This review has explored the status of application of ETT in India for the improvement of cattle and buffalo. Birth of calves after in vivolin vitro embryo production and transfer to the surrogate mother, is the successful outcome of careful and meticulous execution of various interdependent steps. Important works performed in lndia for the success of each step of ETT to ultimately improve embryo/calf production have been discussed. Recovery of mean 3.9 and 2.8 VE and 38 and 27% conception (using non-freezable embryos) in cattle and buffalo, respectively, in the year 1995-96, in our country indicates that there had been considerable improvement in MOET technology in a short span of less than a decade. These results and application of this technology in India had demonstrated that this technology can be used commercially for the production of breeding stock of dairy animals. In view of acute shortage of breeding bulls and elite animals, especially of Indian breeds, this technology has more relevance to our country. There is need to set up regional stations for faster multiplication of these elite animals to produce bulls required for that region aid their genetic evaluation through sibling testing (ONBS), before they can be used for wider dissemination of germ plasm using AI. The technique of ovum pick-up and in vitro embryo production is far more efficient and economic; however, there is need to do extensive research in vitro maturation, fertilization and culture of oocytes/embryos to improve efficiency of in vitro embryo production (IVEP) and in turn calf production. In any case, to keep pace with the development of emerging biotechnologies such as somatic cell cloning, transgenic livestock production, stem cell technology etc. and the inherent revolutionary benefits of these technologies to mankind, it is necessary to acquire competence in the IVEP.