The Development and Application of the Modern Reproductive Technologies to Horse Breeding

Although the horse was probably the first animal to experience and benefit from artificial insemination, it trailed the field somewhat with regard to the application of embryo transfer and other oocyte and embryo-related modern breeding technologies. But with a late run it is now back in mid-field and gaining fast on the other large domestic species in the application of the many technological advances of the past 20 years to sound breeding practice. Improvements in extenders and cryoprotectants have resulted in a veritable upsurge in the transport and insemination of cooled and frozen stallion semen, and parallel improvements in ovulation induction and synchrony, exogenous gonadotrophic stimulation of multiple fertile ovulations and simplified, more efficient methods for non-surgical transfer of embryos to recipient mares, coupled with relaxation of breed society registration restrictions, have together contributed to a similar upsurge in the application of embryo transfer to all breeds and athletic types of horses worldwide, with the continuing and notable exception of the Thoroughbred. Although conventional in vitro fertilization remains something of an unjumped fence in equids, other modern breeding technologies like hysteroscopic low-dose insemination, fluorescence-activated sex sorting of stallion spermatozoa, between-species embryo transfer, embryo freezing and bisection, transvaginal ultrasound-guided oocyte collection, intracytoplasmic sperm injection for fertilization (ICSI), gamete intrafallopian transfer (GIFT) and now nuclear transfer (cloning), have all been applied to equids with encouraging success. Cloning, especially, holds enormous promise for the Sporthorse industry to re-create champion geldings in stallion form for breeding purposes.

From 'public service' to artificial insemination: animal breeding science and reproductive research in early twentieth-century Britain

Artificial insemination (AI) was the first conceptive technology to be widely used in agriculture. Whereas at the beginning of the twentieth century all cows in England and Wales were mated to bulls, by the end of the 1950s 60% conceived through artificial insemination. By then a national network of 'cattle breeding centres' brought AI within the reach of every farmer. In this paper I explore how artificial insemination, which had few supporters in the 1920s and 1930s, was transformed into an 'indispensable' method for reproducing cattle. I discuss the factors that made organised AI possible (but still negotiable and controversial), including changes in cultures of cattle breeding, novel State involvement in bovine reproduction, the rise of new 'animal breeding research' centres at Cambridge, Edinburgh and Reading universities, war preparations and central planning by the Milk Marketing Board (from 1933). I go on to show that the unprecedented focus on bovine reproduction set in motion by the AI centres effectively generated new networks of reproductive research, through these the 'biopower' of the farm was incorporated into the clinic. The example of AI shows that by combining the history of reproductive technology in agriculture and medicine we can give a richer account of modern reproduction.

Reproduction in domestic ruminants during the past 50 yr: discovery to application

The study of reproductive physiology in domestic ruminants has progressed from the whole animal to the molecular level in an amazingly short period of time. The volume of information on this subject is enormous; therefore, we have focused on domestic ruminants, with an emphasis on cattle. To date, artificial insemination (AI) is perhaps the most powerful technique that reproductive physiologists and geneticists have provided the livestock industry for genetic improvement. Early efforts to establish AI as a tool were initiated in Russia around 1899 and since that time major advances in methods of semen collection, evaluation of male fertility, cryopreservation of sperm, sex-sorted semen, and estrous cycle control have occurred. The preceding advances not only led to the widespread use of AI, but also contributed to our fundamental understanding of ovulation control, timing of insemination, gamete biology, and cryopreservation. In regards to anestrus, our understanding of the concept of neuroendocrine control of the pituitary gland and the role of steroid feedback led to the Gonadostat Theory, which proposes that onset of puberty is due to a decrease in the negative feedback of gonadal steroids over time. Subsequent studies in prepuberal and postpartum sheep and cattle established that a short luteal phase frequently precedes the first normal length cycle that is accompanied by estrous expression. This observation led to the common practice of treating prepuberal heifers and anestrous postpartum cows with a short-term progestin treatment (e.g., Controlled Internal Drug Release) to induce normal estrous cycles. In domestic ruminants, fertilization rate is high (85% to 95%); however, significant embryonic mortality before or around the time of maternal recognition of pregnancy (MRP) reduces the pregnancy rate to a single breeding. Significant effort has been directed at determining the time of MRP, the signal for MRP, as well as elucidating the physiological, cellular, and molecular dialogue between the conceptus and uterine environment. Advancements have now led us to the ability to edit the genome to alleviate disease and possibly improve production traits. In summary, major advancements in our understanding of reproductive biology have stemmed from efforts to establish the AI and embryo transfer technique and reduce the negative impact of anestrus and embryonic mortality in domestic ruminants.

The work of the Animal Research Station, Cambridge

This paper traces the history of the Animal Research Station, Cambridge from its establishment in 1932 to its closure in 1986. The author worked there for forty years and was Director from 1979. Originally set up as a field station for Cambridge University's School of Agriculture, the Station was expanded after World War II as the Agricultural Research Council's Unit of Animal Reproduction. Beginning with semen and artificial insemination, research at the Station soon embraced superovulation and embryo transfer in farm animals. Many other technologies were also developed here, including IVF in pigs, cloning by nuclear transplantation of early embryonic cells, and the first genetically modified farm animals in Britain. This account recalls the Directors of the Station and their research teams together with details of their pioneering contribution to reproductive biology.

Artificial insemination and eugenics: celibate motherhood, eutelegenesis and germinal choice

This paper traces the history of artificial insemination by selected donors (AID) as a strategy for positive eugenic improvement. While medical artificial insemination has a longer history, its use as a eugenic strategy was first mooted in late nineteenth-century France. It was then developed as 'scientific motherhood' for war widows and those without partners by Marion Louisa Piddington in Australia following the Great War. By the 1930s AID was being more widely used clinically in Britain (and elsewhere) as a medical solution to male infertility for married couples. In 1935 English postal clerk, Herbert Brewer, promoted AID (eutelegenesis) as the socialization of the germ plasm in a eugenic scheme. The next year Hermann Muller, American Drosophila geneticist and eugenicist, presented his plan for human improvement by AID to Stalin. Some twenty years later, Muller, together with Robert Klark Graham, began planning a Foundation for Germinal Choice in California. This was finally opened in 1980 as the first practical experiment in eugenic AID, producing some 215 babies over the twenty years it functioned. While AID appeared to be a means of squaring a eugenic circle by separating paternity from love relationships, and so allowing eugenic improvement without inhibiting individual choice in marriage, it found very little favour with those who might use it, not least because of a couple's desire to have their 'own' children has always seemed stronger than any eugenic aspirations. No state has ever contemplated using AID as a social policy.

The invention of artificial fertilization in the eighteenth and nineteenth century

Artificial insemination and other fertilization techniques are today considered central to the history of reproductive medicine. The medical treatment of infertile couples, however, constitutes just a small part of the whole story of artificial fertilization. Lazzaro Spallanzani (1729-1799) in particular, said to have been the inventor of artificial insemination, did not develop this method for medical purposes. He belonged to a generation of naturalists to whom artificial insemination was part of a heterogeneous series of investigations that were undertaken to explore the natural history of animal generation. Questions concerning conception, the role of the gametes, the definition of species, the production of hybrids or livestock breeding were all included in these investigations. Thus, no one strain of thought, nor single set of ideas or interests, entirely shaped the development of artificial fertilization.

Great expectations--German debates about artificial insemination in humans around 1912

In May 1912, reports on successful attempts at artificial insemination hit the German papers. Over the following months, the topic was taken up in medical lectures, in the debates of medical associations, and in medical journals. The technique--which had not much changed since the days of James Marion Sims--apparently triggered the imagination of scientists, medical doctors, journalists and authors. That artificial insemination met such interest, however, was not primarily due to its medical usefulness or proven success. Given that insemination with donor sperm was out of the question for most doctors and that ideas about the fertile period within the menstrual cycle were erroneous, contemporary attempts at insemination in humans hardly ever worked. Public interest in this topic rather reflects the desires and expectations which contemporaries associated with artificial insemination and with modern, scientific medicine. What appears to be a comparatively straight forward, low-tech operation today was imagined as a way or creating life artificially. Thus the topic was able to mobilise fears and expectations. The debate not only reflected contemporary beliefs about the possibilities and dangers of modern medicine, it also addressed the meaning of reproduction and infertility and the future of gender relations.

Cutting across nature? The history of artificial insemination in pigs in the United Kingdom

Artificial insemination (AI) has a considerable cultural significance in addition to its economic and technical impact. This study is the first to examine the history of its application to pigs, and uses evidence provided directly by both the scientists involved in its development, and some of the farmers who were among the first to use it, in addition to archival and published sources, to show how the scientific studies of the 1950s evolved into a widely available commercial product by the 1980s. It describes the initial scientific work and quantifies the extent to which the technique was used at various points in time, showing that by 1990 nearly one half of UK pig herds were using AI for more than 25% of all services. It traces changes in the techniques employed and argues that these were the result of a multi-dimensional process of contemporaneous change. The various dimensions are identified firstly as authorities, meaning the people and organisations controlling the perception, administration, control, and so on, of the technique; secondly the discourses employed by the authorities; and thirdly the media by which the discourses were disseminated. Finally, it is suggested that this approach might be used more widely to examine the construction of other technologies.

Lazzaro Spallanzani: At the roots of modern biology

The scientific work of Lazzaro Spallanzani is outlined, with emphasis on the elements of originality in his introduction of the experimental method in biology. Particular stress is placed on Spallanzani's contribution to solving the Theoria Generationis, from the problems connected with the spontaneous generation of living creatures to those of natural fertilization and artificial insemination and, finally, those of regeneration. J. Exp. Zool. (Mol. Dev. Evol.) 285:178-196, 1999.

Intrauterine insemination for treatment of male infertility

Intrauterine inseminations (IUI) have been performed since the beginning of this century for treatment of infertility. Despite its widespread use the clinical value of this technique remains unclear. Today, indications for IUI include male factor, cervical factor, immunological and unexplained infertility and infertility due to ejaculatory disorders. IUI is superior to intravaginal (IVI) or intracervical insemination (ICI). Before insemination, semen has to be processed using one of the established sperm preparation techniques. Different techniques seem to be equally effective in preparing a highly concentrated sperm fraction with progressively motile, morphologically normal sperm. Ovarian stimulation further improves pregnancy rates achieved by insemination. Human menopausal gonadotropin (HMG) stimulation seems to be superior to clomiphene citrate stimulation. Among other factors, timing and number of inseminations are crucial when influencing the outcome of IUI treatment.

Reproduction and rationality

Many years ago, the esteemed patriarch of bioethics, Joseph Fletcher, spoke loud and clear in favor of rationality in reproduction. By rationality, he meant not merely limiting population growth, which he certainly favored, but bringing to bear human analytic and creative intelligence on the random and instinctive activities of sexual intercourse and procreation that we share with all mammals. In his 1974 book, The Ethics of Genetic Control: Ending Reproductive Roulette, he foresaw most of the issues that we are facing today. He reflected on artificial insemination, prenatal diagnosis, cloning, eugenics, ectogenesis, ovum transfers, and genetic engineering. He examined these innovations to the extent that he felt that each of them represents a way of exercising rational and responsible control over life and reproduction. The subtitle of his book, “Ending Reproductive Roulette,” proclaims his faith. Dr. Fletcher's dedication to rationality led him to make the astonishing statement, “Man is a maker and the more rationally contrived and deliberate anything is, the more human it is. Therefore, laboratory reproduction is radically human compared to conception by ordinary heterosexual intercourse.”