In the past half-century, great progress has been made in the reproductive management of farm animals, both mammals and birds. The present text aims to provide information on developments that have occurred over the years and to indicate areas in which reproductive technologies may usefully be employed, whether in commerce or research. Of the countless thousands of scientific publications dealing with reproductive technologies, only a small number are provided in the main text (essentially confined to reports appearing in the years 2000–2004). Tables dealing with landmark events in the development of the various technologies and pointing to those associated with them are provided in the various chapters. Those who wish to delve deeper into the subject matter can consult various of the texts mentioned in Appendix A. For a look at work at the research level and to find most of the papers dealt with in the text, Appendix B contains a list of journals that can be found in a good university library.
In the context of reproductive technologies emerging since the Second World War, the 1940s and 1950s saw the widespread establishment of artificial insemination and the introduction of frozen semen in cattle breeding; the end of the century saw the first moves to commercialize semen sexing technology. In the early 1960s, as well as being an ingredient in the human contraceptive pill, progestogens were shown to be highly effective when administered by the intravaginal route, leading to commercially acceptable techniques for the control of the oestrous cycle and breeding season in sheep and goats. In the late 1960s came a revolution in the measurement of hormones in body fluids with the introduction of the exquisitely sensitive radioimmunoassay (RIA) techniques, which provided a new approach to early pregnancy diagnosis; emerging around the same time were early forms of ultrasonics, which could also be employed in the detection of pregnancy.
The 1970s were to see embryo transfer and the freezing of embryos in cattle becoming commercial realities and their incorporation into increasingly effective breeding improvement programmes. With the availability of prostaglandins (PGs) and gonadotrophinreleasing hormone (GnRH), that decade also witnessed new possibilities for oestrus control in cattle and horses.The first steps towards mammalian cloning were taken in the mid-1980s and a few years later came the ability to produce cattle embryos in the laboratory in large numbers and at low cost. The 1990s were to witness the dramatic emergence of somatic cell cloning with the birth of Dolly the sheep, opening the way to new possibilities for the production of transgenic farm animals. It is perhaps worthy of a mention that there is an Irish connection, talking about recombinant DNA technology and its application in the production of transgenic animals.
In the context of reproductive technologies emerging since the Second World War, the 1940s and 1950s saw the widespread establishment of artificial insemination and the introduction of frozen semen in cattle breeding; the end of the century saw the first moves to commercialize semen sexing technology. In the early 1960s, as well as being an ingredient in the human contraceptive pill, progestogens were shown to be highly effective when administered by the intravaginal route, leading to commercially acceptable techniques for the control of the oestrous cycle and breeding season in sheep and goats. In the late 1960s came a revolution in the measurement of hormones in body fluids with the introduction of the exquisitely sensitive radioimmunoassay (RIA) techniques, which provided a new approach to early pregnancy diagnosis; emerging around the same time were early forms of ultrasonics, which could also be employed in the detection of pregnancy.
The 1970s were to see embryo transfer and the freezing of embryos in cattle becoming commercial realities and their incorporation into increasingly effective breeding improvement programmes. With the availability of prostaglandins (PGs) and gonadotrophinreleasing hormone (GnRH), that decade also witnessed new possibilities for oestrus control in cattle and horses.The first steps towards mammalian cloning were taken in the mid-1980s and a few years later came the ability to produce cattle embryos in the laboratory in large numbers and at low cost. The 1990s were to witness the dramatic emergence of somatic cell cloning with the birth of Dolly the sheep, opening the way to new possibilities for the production of transgenic farm animals. It is perhaps worthy of a mention that there is an Irish connection, talking about recombinant DNA technology and its application in the production of transgenic animals.
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