Advances in Ovine and Caprine Reproduction
Enhancement of reproductive processes under varied environmental and nutritional conditions is the policy of advancement. New advances in biotechnology have provided better breeds of sheep and goats. For sustainable and eco-friendly animal production system, continued use of biotechnology is essential. From embryo transfer, micromanipulations and cloning, we have entered an era of gene selections and their use for specific traits like increased meat and milk production. Of late, endometrium, its secretions, and implantation, sustenance of embryonic tissue and foetal development have been investigated. Endometrium secretions are essential for the development of conceptus. Retinol has played a role in caprine foetal development. The role of caprine epithelial cells in invitro-goat embryo development has also been reported. Various physiological and pharmacological agents help blastocyst development. Embryo culture, embryonic development, early pregnancy associated glycoproteins, vascular endothelial growth factors, oocyte maturation, dominant follicular growth, ovarian structure, growth and development of corpus lutem have been reviewed and wherever possible image illucidation has been incorporated to highlight the significant future areas. Some of the author’s findings on foetal maternal interactions in ovine pregnancy still remain a unique and pioneering work.
The historical perspective of technological advancement in animal reproduction over the years has been reviewed. Out of a host of technologies used during the last centuries, a few were extensively used in improving stocks and herds like artificial insemination, multiple ovulation and embryo transfer. Goats, along with sheep, were among the earliest domestic animals. The reproductive efficiency of these species is higher than other domestic animals such as cattle and horses. Against 70-80% maximum fertility estimates in large domestic animals, fertility rates of 100% have been regular features in sheep and goats. The modern day techniques of hormone induced super-ovulation, synchronizations, embryo culture, invitro fertilization, ovulation detection and embryo manipulations, have culminated into a “Wonder” animal “Dolly”, the sheep, on the 5th of July 1996, which was a landmark in the annals of biotechnology.
Cloning, DNA injections and improvement in productivity through biotechniques, has entered into advanced research and much information on the use of pre-implantation in sheep and goat embryo for production of life saving biologicals is available. It is a positive signal. The production of platelet activating factors and goats producing insulin rich milk is a glimpse of vast expanding biotechnological inventions in ovine and caprine reproduction. The enormous literature on the use of biotechnology in sheep and goats thus needed a review.
This paper aims to sum up various results of the author’s own work on ovulation, detection, folliculogenesis, corpus luteum growth and development, super-ovulation, invitro-fertilization and embryo culture. Some of the preliminary investigations on ultra-sonography, laparoscopy, prenatal and foetal development still hold ground as the only records. An attempt has been made in this paper to present the author’s own findings and discuss them in a global scenario. The reflections of this author’s 30 years of research in ovine and caprine reproduction have extensively been cited in more than 500 citations all over the world.
The author of this paper is Dr. G. M. Wani. He has written and contributed more than 200 papers in research journals and conferences in the field of biotechnologies of small ruminants. To mention just one of them, his scholarly paper Multiple Management System can be found in the Encyclopedia of Dairy Sciences, published by Elsevier Academic Press, UK. Dr. Wani has worked in international institutes of repute, including the Veterinary University of Hanover, Germany; and the Veterinary Research Institute in India. He has a number of national and international awards to his credit, and his biography is included in many leading biographies. At present, Dr. Wani is Director of Extension Education at the University of Agricultural Sciences and Technology, Srinagar, Kashmir, India.
Number of Words: 6,725
Number of Pages: approx. 25