Development Of Artificial Insemination Research Articles

An Overview of Artificial Insemination: A Journey from Past to Present

Artificial insemination (AI) has a rich history spanning centuries, beginning with early experiments in plant and animal reproduction. This article traces the development of AI from its earliest recorded instances in 1322 A.D. to modern-day advancements. Notable pioneers such as Spallanzani, Hunter, and Ivanoff contributed significantly to the evolution of AI techniques. The introduction of AI across various animal species, including cattle, horses, sheep, goats, pigs, and poultry, revolutionized breeding practices worldwide. Key milestones include the development of semen extenders, the invention of artificial vaginas for semen collection, and the advent of cryopreservation techniques. Moreover, advancements in sperm quality assessment and estrous synchronization further enhanced AI efficiency. The introduction of sexed semen technology has provided a means to control offspring gender, offering new avenues for genetic selection. Overall, AI has played a crucial role in improving livestock genetics, disease control, and reproductive efficiency, making significant contributions to agricultural productivity and sustainability.

Microbial composition of goat buck's ejaculates is modified by the process of preparing and storing refrigerated semen doses

Ejaculates present their own microbiota, and a link between ejaculates' microbiota and sperm quality and fertility exists. With the development of artificial insemination in animal breeding, ejaculates must be manipulated by diluting them with extenders and storing them at temperatures below body temperature. The effects that these processes have on the original semen microbiota have never been studied. This study explores the effects of the protocol for preparing refrigerated goat buck semen doses and storing on seminal microbiota. Semen from six adult goat bucks of the Murciano-Granadina breed (24 ejaculates) was used, cooled to 4 °C in a skimmed milk-based extender, and stored at this temperature for 24 h. Samples were taken in different steps: in the raw ejaculates (ejaculates), after dilution with the refrigeration extender (diluted), immediately after reaching 4 °C (chilled 0 h) and the samples refrigerated at 4 °C and stored at this temperature for 24 h (chilled 24 h). Sperm quality (motility and integrity of plasma and acrosomal membrane, and mitochondrial functionality) was also evaluated. Bacterial 16S rRNA sequencing was used to study the seminal microbiota. Our results indicated that both refrigeration and storage at 4 °C negatively affected sperm quality parameters. Preparing semen doses and their subsequent conservation caused a significant change in the bacterial community structure. Raw ejaculates showed a lower Pielou's evenness index than the other samples (diluted, chilled 0 h and chilled 24 h). Ejaculates also had a lower Shannon's diversity index (3.44) than the diluted semen (4.17) and the semen chilled for 24 h (4.43). Regarding beta diversity, significant differences were detected between ejaculates and the other treatments. Differences were also found in unweighted UniFrac distances between the semen chilled for 0 h and that chilled for 24 h. At the genus level, marked effects of preparing doses and their subsequent conservation were also evident: 199 genera that were absent in ejaculates were found in the semen chilled and stored for 24 h; 177 genera that were present in ejaculates disappeared after 24-h refrigeration. In conclusion, the extender and protocol for preparing refrigerated goat buck semen doses considerably modify microbial ejaculate composition.

Cinquante années d’amélioration génétique du porc en France : bilan et perspectives

Cette synthèse fait le point sur les principales évolutions de l’amélioration génétique du porc en France depuis la loi sur l’élevage de 1966. Elle évoque rapidement les 20 premières années, qui ont fait l’objet d’une synthèse en 1986, puis décrit plus en détail les évolutions ultérieures. Les objectifs de sélection, initialement limités aux caractères de production, se sont complexifiés avec la prise en compte de la qualité de la viande, puis de la prolificité et enfin des aptitudes maternelles des truies. La mise en place d’une évaluation génétique utilisant la méthodologie du « BLUP - modèle animal » au milieu des années 1990 et le développement de l’insémination artificielle ont profondément changé le travail des sélectionneurs. Une nouvelle évolution majeure, la sélection génomique, a récemment été mise en place. La sélection a conduit à des améliorations importantes des performances pour les principaux caractères de l’objectif de sélection depuis 1970 : plus de 200 g de gain moyen quotidien, plus de 0,5 point d’indice de consommation, plus de 12 points de taux de viande maigre dans la carcasse, jusqu’à près de six porcelets nés vifs par portée supplémentaires. Ces évolutions favorables ont réduit l’empreinte environnementale de la production, mais ont également eu des effets défavorables : une augmentation la mortalité des porcelets avant sevrage et une plus grande hétérogénéité des performances. Les enjeux pour l’avenir en termes d’objectifs d’amélioration génétique (prise en compte de caractères liés au bien-être, à la robustesse et à l’adaptation…), de méthodes et d’outils sont ensuite discutés.

Studies of assisted reproductive technology in the 19th and 20th centuries

Artificial breeding technology has been an important subject of research from the very beginning of medicine and veterinary sciences. Several main directions should be distinguished within these methods: artificial insemination (including cryogenic semen preservation technology), transplantation (embryo transfer) and embryo culture in vitro. The first experiments in this field date back to the late 18th century, when Lazarro Spallanzani performed such experiments on animals. The late 19th and the early 20th centuries saw the development of artificial insemination, which became a routine procedure, significantly facilitating breeding. The first successful experiments in embryo transplantation were also carried out in 1890. The high potential of this method was recognized related to the intensification of breeding for specific individual traits without limitations imposed by breeding physiology. These procedures were limited for a long time to scientific experiments and were not introduced into medical practice until the early 1970s. Embryo culture in vitro was a separate problem and an even greater challenge for researchers. Significant experimental research in this field started only in 1949 and has been continued ever since. In the 1990s, the biotechnology of in vitro embryo culture was improved to the point of becoming one of the most promising fields of veterinary and zootechnical sciences.

A 100-Year Review: Reproductive technologies in dairy science

Reproductive technology revolutionized dairy production during the past century. Artificial insemination was first successfully applied to cattle in the early 1900s. The next major developments involved semen extenders, invention of the electroejaculator, progeny testing, addition of antibiotics to semen during the 1930s and 1940s, and the major discovery of sperm cryopreservation with glycerol in 1949. The 1950s and 1960s were particularly productive with the development of protocols for the superovulation of cattle with both pregnant mare serum gonadotrophin/equine chorionic gonadotrophin and FSH, the first successful bovine embryo transfer, the discovery of sperm capacitation, the birth of rabbits after in vitro fertilization, and the development of insulated liquid nitrogen tanks. Improved semen extenders and the replacement of glass ampules with plastic semen straws followed. Some of the most noteworthy developments in the 1970s included the initial successes with in vitro culture of embryos, calves born after chromosomal sexing as embryos, embryo splitting resulting in the birth of twins, and development of computer-assisted semen analysis. The 1980s brought flow cytometric separation of X- and Y-bearing sperm, in vitro fertilization leading to the birth of live calves, clones produced by nuclear transfer from embryonic cells, and ovum pick-up via ultrasound-guided follicular aspiration. The 20th century ended with the birth of calves produced from AI with sexed semen, sheep and cattle clones produced by nuclear transfer from adult somatic cell nuclei, and the birth of transgenic cloned calves. The 21st century has seen the introduction of perhaps the most powerful biotechnology since the development of artificial insemination and cryopreservation. Quick, inexpensive genomic analysis via the use of single nucleotide polymorphism genotyping chips is revolutionizing the cattle breeding industry. Now, with the introduction of genome editing technology, the changes are becoming almost too rapid to fully digest.

Estimating the binding ability of collared peccary (Pecari tajacu Linnaeus, 1758) sperm using heterologous substrates

In collared peccaries, the development of artificial insemination (AI) is scarce, requiring search for alternative methods for the evaluation of sperm fertilizing ability. Thus, the aims of this study were to estimate the binding capability of collared peccaries sperm, using swine oocytes and the egg perivitelline membrane, and to evaluate the prognostic value of sperm parameters on the in vitro interactions among sperm and heterologous substrates. Eleven ejaculates were collected by eletroejaculation and evaluated for viability and morphology by light microscopy, for functionality by hypo-osmotic swelling test, for plasma membrane integrity by epifluorescence microscopy, and for sperm motility by computerized analysis. Subsequently, for analysis of the in vitro interactions, sperm samples were cultured in an incubation medium with swine oocytes and egg perivitelline membrane for 18 h and 20 min, respectively, at 38.5 °C and humidified atmosphere. The sperm-oocyte interaction rate was 100% with sperm penetrating 19.8+ 5.5% of oocytes. The average values of bound sperm and penetrated sperm per oocyte were 39.4 + 4.6 and 2.5 + 0.7, respectively. Already for perivitelline membrane binding assay, all samples presented sperm bound (100%) with average of 140.6 ± 19.4 bound sperm (range 33.9–308.7). Moreover, positive correlations were observed for the number of sperm bound to swine oocytes and osmotic response (r = 68.5%; P = 0.02), membrane integrity (r = 65.1%; P = 0.03), and straightness (r = 66.5%; (P = 0.03), as weel as for the number of sperm bound to egg perivitelline membrane and sperm viability (r = 74.0%; P = 0.01), total motility (r = 63.6%; P = 0.04), and linearity (r = 70.5%; P = 0.02). Finally, a negative correlation among slow (r = −80.5%; P = 0.01) and static (r = −84.3%; P = 0.01) sperm with the egg perivitelline membrane was observed. In conclusion, swine oocytes and perivitelline membrane can be used as indicators for the functional evaluation of the binding capability of sperm derived from collared peccaries. These tests could be incorporated into the routine of semen technologies.

Factores ambientales que influyen en el éxito de la inseminación artificial en la raza ovina Rasa Aragonesa

El éxito de la inseminación artificial (IA) en ganado ovino se basa en los valores obtenidos de fecundidad, fertilidad, y prolificidad. El objetivo de este trabajo es valorar la importancia práctica sobre dicho éxito de diversos factores ambientales, ajenos al proceso de recogida y preparación del semen propiamente dicho: identidad del macho, ganadería, mes de la inseminación, temperatura ambiental, circunstancias ambientales, realización o no de flushing, manejo durante la inseminación, desarrollo de la inseminación, técnico inseminador, centro de recogida de semen, año, día tras el parto. Se han analizado datos de los últimos 10 años correspondientes a 5935 lotes, con un total de 58 602 ovejas Rasa Aragonesa, procedentes de 172 explotaciones. Se han detectado numerosos factores con efectos significativos (p<0,010) sobre el éxito de IA (macho, mes IA; temperatura ambiental, flushing, desarrollo de Ia IA y ganadería), pero, en general, cada uno de ellos explica por separado una pequeña parte de la variación en el éxito de la IA. Alcanzar los mejores resultados posibles en los protocolos de IA ovina requiere el control de dichos factores ambientales durante la inseminación; una buena formación y experiencia del inseminador y una total coordinación de la actuación de técnicos y ganaderos son imprescindibles.

Wombat reproduction (Marsupialia; Vombatidae): an update and future directions for the development of artificial breeding technology

This review provides an update on what is currently known about wombat reproductive biology and reports on attempts made to manipulate and/or enhance wombat reproduction as part of the development of artificial reproductive technology (ART) in this taxon. Over the last decade, the logistical difficulties associated with monitoring a nocturnal and semi-fossorial species have largely been overcome, enabling new features of wombat physiology and behaviour to be elucidated. Despite this progress, captive propagation rates are still poor and there are areas of wombat reproductive biology that still require attention, e.g. further characterisation of the oestrous cycle and oestrus. Numerous advances in the use of ART have also been recently developed in the Vombatidae but despite this research, practical methods of manipulating wombat reproduction for the purposes of obtaining research material or for artificial breeding are not yet available. Improvement of the propagation, genetic diversity and management of wombat populations requires a thorough understanding of Vombatidae reproduction. While semen collection and cryopreservation in wombats is fairly straightforward there is currently an inability to detect, induce or synchronise oestrus/ovulation and this is an impeding progress in the development of artificial insemination in this taxon.

WHY DO WE NEED TRANSGENIC ANIMALS?

Genetic modification of animals through cross breeding and selection has probably been practiced since wild animals were first domesticated, but became more intensive beginning ~200 years ago with the creation of defined breeds with specialised phenotypes. This generality applies both to agriculturally important species, such as chickens and cattle, and to companion animals, such as cats and dogs. It also applies to plants. In the 20th century, new technologies designed to improve agricultural productivity, perhaps best illustrated by the development of artificial insemination and sperm cryopreservation for the dairy industry, as well as improved nutrition and veterinary care, all fueled by generous government support of agricultural research, accelerated progress towards providing low-cost, safe, and nutritious food for a burgeoning world population. Progress in some cases has been quite remarkable, especially in milk and meat production. The report by Palmiter, Brinster and colleagues in 1982, that mice harboring a transgene for growth hormone under the control of a metallothionein gene promoter grew faster than control siblings, raised the spectre of using relatively simple, one-step gene insertions, rather than cross-breeding and selection, to improve the production of milk, meat, and fibre, and enhance animal health quickly and directly. Although agronomy and horticulture have been able to benefit greatly from applying genetic modification to plants, there has been only very slow application of transgenesis to animal agriculture and aquaculture. The main goal of my talk will be to illustrate some of the difficulties, both scientific and social, that have been encountered in bringing genetic modification and related technologies, such as cloning, into mainstream agriculture. I shall also discuss the competitive advantage held by rodents over alternative animal models in biomedical sciences but argue that the latter still have an important role to play in this regard. A final topic will be to review the potential value of pluripotent stem cells for introducing genetic change in domestic species and for testing the efficacy and safety of grafts derived from pluripotent stem cells before human clinical trials.

Artificial insemination in South American camelids and wild equids

An overview of the present status of the use of artificial insemination (AI) in South American camelids and wild equids is offered. Technical aspects of semen collection, dilution and cryopreservation have limited the development and use of AI in camelid and equid species. To-date, efficiency is low but progress has been made and viable offspring have been produced through the use of AI in domestic South American camelids using both fresh and frozen semen. The origin, composition, and function of the viscous component of camelid seminal plasma remain a mystery and an obvious area for future research. A better understanding of the normal constituents of seminal plasma will enable the rational design of semen extenders suitable for camelids. Post-thaw sperm viability is very low, and studies are needed to address questions of optimal freezing and thawing procedures as well as the insemination dose. The basis for differences in reported pregnancy rates with sexed and frozen semen in domestic equids, and the ultimate success of AI in wild equids will require continued research into the “stallion effect”, extenders and cryoprotectants, optimal volume and number of spermatozoa, temperatures during handling, processing an transport, and insemination techniques. In both camelids and equids, research on domestic species under controlled conditions provides and excellent opportunity to develop effective semen handling techniques for application in wild and endangered species of the respective families.

The Ethics and Role of AI with Fresh and Frozen Semen in Dogs

The use of artificial insemination (AI) with fresh semen has resulted in many benefits for the management of dog breeding, but there are disadvantages that can sometimes be overlooked. Furthermore, poorer quality semen arising as a result of cryopreservation necessitates uterine insemination, which raises the potential for surgical insemination. A number of significant ethical concerns have been raised by key stakeholders (such as The Kennel Club and the Royal College of Veterinary Surgeons) about AI per se, but particularly about the use of surgical insemination. This paper discusses the technological development of AI and explores a number of the ethical issues raised by its application to dog breeding. An Ethical Matrix method is used to map the potential ethical issues for key interest groups, namely dogs, breeders, owners, veterinarians and wider society. There are national variations in the way in which institutions have evaluated potential ethical impacts, and this is reflected in the different regulatory frameworks governing the use of AI in dogs. In order to facilitate decision-making and reduce some of the ethical risks associated with this technology, the veterinary research community could take several proactive steps including: (i) clarifying clinical decision-making processes, (ii) enhancing informed choice among clients and (iii) increasing the knowledge-base of potential impacts of AI.

The history of artificial insemination: Selected notes and notables1

Artificial insemination (AI) was the first great biotechnology applied to improve reproduction and genetics of farm animals. It has had an enormous impact worldwide in many species, particularly in dairy cattle. The acceptance of AI technology worldwide provided the impetus for developing other technologies, such as cryopreservation and sexing of sperm, estrous cycle regulation, and embryo harvesting, freezing, culture and transfer, and cloning. New, highly effective methods of sire evaluation were developed. The history of development of AI is reviewed, particularly in dairy cattle, in which the impact on genetic improvement and control of venereal diseases have been greatest. Other

Biochemical characterization and purification of sperm agglutination antigen-1, A human sperm surface antigen implicated in gamete interactions

Reproductive technology revolutionized dairy production during the past century. Artificial insemination was first successfully applied to cattle in the early 1900s. The next major developments involved semen extenders, invention of the electroejaculator, progeny testing, addition of antibiotics to semen during the 1930s and 1940s, and the major discovery of sperm cryopreservation with glycerol in 1949. The 1950s and 1960s were particularly productive with the development of protocols for the superovulation of cattle with both pregnant mare serum gonadotrophin/equine chorionic gonadotrophin and FSH, the first successful bovine embryo transfer, the discovery of sperm capacitation, the birth of rabbits after in vitro fertilization, and the development of insulated liquid nitrogen tanks. Improved semen extenders and the replacement of glass ampules with plastic semen straws followed. Some of the most noteworthy developments in the 1970s included the initial successes with in vitro culture of embryos, calves born after chromosomal sexing as embryos, embryo splitting resulting in the birth of twins, and development of computer-assisted semen analysis. The 1980s brought flow cytometric separation of X- and Y-bearing sperm, in vitro fertilization leading to the birth of live calves, clones produced by nuclear transfer from embryonic cells, and ovum pick-up via ultrasound-guided follicular aspiration. The 20th century ended with the birth of calves produced from AI with sexed semen, sheep and cattle clones produced by nuclear transfer from adult somatic cell nuclei, and the birth of transgenic cloned calves. The 21st century has seen the introduction of perhaps the most powerful biotechnology since the development of artificial insemination and cryopreservation. Quick, inexpensive genomic analysis via the use of single nucleotide polymorphism genotyping chips is revolutionizing the cattle breeding industry. Now, with the introduction of genome editing technology, the changes are becoming almost too rapid to fully digest.

Evaluation of frequency of ultrasonically guided follicle aspiration on bovine ovarian dynamics

Reproductive technology revolutionized dairy production during the past century. Artificial insemination was first successfully applied to cattle in the early 1900s. The next major developments involved semen extenders, invention of the electroejaculator, progeny testing, addition of antibiotics to semen during the 1930s and 1940s, and the major discovery of sperm cryopreservation with glycerol in 1949. The 1950s and 1960s were particularly productive with the development of protocols for the superovulation of cattle with both pregnant mare serum gonadotrophin/equine chorionic gonadotrophin and FSH, the first successful bovine embryo transfer, the discovery of sperm capacitation, the birth of rabbits after in vitro fertilization, and the development of insulated liquid nitrogen tanks. Improved semen extenders and the replacement of glass ampules with plastic semen straws followed. Some of the most noteworthy developments in the 1970s included the initial successes with in vitro culture of embryos, calves born after chromosomal sexing as embryos, embryo splitting resulting in the birth of twins, and development of computer-assisted semen analysis. The 1980s brought flow cytometric separation of X- and Y-bearing sperm, in vitro fertilization leading to the birth of live calves, clones produced by nuclear transfer from embryonic cells, and ovum pick-up via ultrasound-guided follicular aspiration. The 20th century ended with the birth of calves produced from AI with sexed semen, sheep and cattle clones produced by nuclear transfer from adult somatic cell nuclei, and the birth of transgenic cloned calves. The 21st century has seen the introduction of perhaps the most powerful biotechnology since the development of artificial insemination and cryopreservation. Quick, inexpensive genomic analysis via the use of single nucleotide polymorphism genotyping chips is revolutionizing the cattle breeding industry. Now, with the introduction of genome editing technology, the changes are becoming almost too rapid to fully digest.

Future prospectives on animal biotechnology

Abstract Farm animal reproduction is entering the era of embryo engineering ‐ a part of the new biotechnology revolution that has been sweeping the nation during the early 1980s. This comes at a time when the $70 billion livestock industry is hard‐pressed for survival. Not since the commercial development of artificial insemination (AI) techniques in the 1950s has any new technical research development caused such a stir in the livestock community. The genetic impact of artificial insemination (AI) in the cattle industry these last 40 years cannot be questioned. Nearly three‐fourths of the dairy cattle in the United States are now being artificially inseminated. Also, commercial processing of bull semen has been and still is a major agribusiness success story, grossing millions of dollars annually. With the development of embryo transfer (ET) technology in the mid‐1970s, animal reproduction again entered a new age of technical advancement. It appears that AI and embryo methodology are just the beginning o...

The production of monozygotic twins of preselected parentage by micromanipulation of non-surgically collected cow embryos

Reproductive technology revolutionized dairy production during the past century. Artificial insemination was first successfully applied to cattle in the early 1900s. The next major developments involved semen extenders, invention of the electroejaculator, progeny testing, addition of antibiotics to semen during the 1930s and 1940s, and the major discovery of sperm cryopreservation with glycerol in 1949. The 1950s and 1960s were particularly productive with the development of protocols for the superovulation of cattle with both pregnant mare serum gonadotrophin/equine chorionic gonadotrophin and FSH, the first successful bovine embryo transfer, the discovery of sperm capacitation, the birth of rabbits after in vitro fertilization, and the development of insulated liquid nitrogen tanks. Improved semen extenders and the replacement of glass ampules with plastic semen straws followed. Some of the most noteworthy developments in the 1970s included the initial successes with in vitro culture of embryos, calves born after chromosomal sexing as embryos, embryo splitting resulting in the birth of twins, and development of computer-assisted semen analysis. The 1980s brought flow cytometric separation of X- and Y-bearing sperm, in vitro fertilization leading to the birth of live calves, clones produced by nuclear transfer from embryonic cells, and ovum pick-up via ultrasound-guided follicular aspiration. The 20th century ended with the birth of calves produced from AI with sexed semen, sheep and cattle clones produced by nuclear transfer from adult somatic cell nuclei, and the birth of transgenic cloned calves. The 21st century has seen the introduction of perhaps the most powerful biotechnology since the development of artificial insemination and cryopreservation. Quick, inexpensive genomic analysis via the use of single nucleotide polymorphism genotyping chips is revolutionizing the cattle breeding industry. Now, with the introduction of genome editing technology, the changes are becoming almost too rapid to fully digest.

Development of artificial insemination in pigs in E.A.A.P. countries

By means of a questionnaire, an attempt was made to get an impression of the development of A.I. in pigs (including its causes) in the E.A.A.P. countries. The questionnaire was sent to 26 countries: 12 returned it, and two other countries answered that they did not use A.I. in pigs (Portugal and Luxemburg). The conclusions which might be drawn from these questionnaires are: 1. (1) During the last few years the use of A.I. in pigs has been expanding very rapidly, although in most countries it is of minor importance in total pig production. 2. (2) A.I. in pigs is developing from a breeding A.I. to a production A.I. 3. (3) “Do-it-Yourself” A.I. in pigs plays a minor role in those countries where A.I. in pigs has been most developed, although the system is expanding now. It probably has to be preceded by a development of the normal inseminator service. 4. (4) In some countries the pregnancy rates of A.I. in pigs are about equal to those of natural mating; there are, however, large differences between the countries. 5. (5) It seems to be important for the development of pig A.I., that it is accepted in the national pig improvement programmes.

What We Need to Know About Conformational and Managemental Traits: The Commercial Dairyman

There have been many systems designed to estimate a site's genetic merit or his ability to transmit desirable genetic traits to his progeny. While animal breeding has often been called an art, it is now considered by most to be a science. The dairyman must know the factors involved in inheritance, he must have the skills to apply them, and he must have patience to await fruition. Science has greatly reduced the risk of failure and the mediocrity that often resulted from earlier breeding practices of breeding the best to the best. Indeed, application of genetics has contributed greatly to achievements and progress in dairy cattle breeding. The rate of genetic progress in the dairy cattle population has increased materially since 1937, the date of the first (USDA-DHIA) United States Department of Agriculture Dairy Herd Improvement Sire Summary. Since the development of artificial insemination and, later, with the increased use of computers, the potential influence of fewer sires has been demonstrated. Major revisions were made in the USDADHIA sire evaluation program in 1962 by the daughter-herdmate comparison. In 1965, a new method for evaluation, calculating, and expressing a site's genetic merit by Predicted Difference and Repeatability was adopted. Most breed associations and artificial insemination (AI) organizations also have the/r own genetic evaluation programs based on production, and a few include type characteristics. All of these systems are serious attempts to estimate a sires ability to transmit genetic traits. While the breed programs are relatively uniform nationally, most of the other programs have a great deal of variation. T~is variation is between regions of the country as well as be-

Progress in the Application of Artificial Insemination in Other Countries

During the last twelve months short tours were made in Denmark, Canada, and the United States and certain impressions were collected, which allied to actual statistics show a picture of the present development of artificial insemination in those countries. The statistics relate mainly to a period ending in 1944, and 1945 figures are not yet available. The absence of a uniform method of collecting and tabulating data in each country makes an accurate comparison rather difficult, but the general trend of progress can nevertheless be determined. It is stressed that it is not easy to confine the subject strictly to progress without at times trespassing on the field reserved for other speakers.

The Organisation and Administration of Artificial Insemination Centres

The scope of this subject is so wide that no attempt will be made to deal with it in detail, but I will treat it in a general way. drawing largely from my experience at the Reading Centre. The technical aspect of artificial insemination has now reached a stage of development where good results are almost a certainty, but more than good results must be achieved if an Artificial Insemination Centre is to be run satisfactorily. It is of great importance that a service be provided at an economic figure, and this can only be done if the administration and organisation of the Centre are on a sound business footing. I intend to confine my remarks to the organisation of the individual Centre, and in case any of the audience are unaware of it, the national development of artificial insemination is controlled by the Minister of Agriculture under the Artificial Insemination (Cattle) (England and Wales) Regulations, 1943, and he has for his guidance the Central Advisory Committee.