Advances In Reproductive Physiology Research Articles

Optimal Dietary Fiber Intake to Retain a Greater Ovarian Follicle Reserve for Gilts.

Simple SummarySuccessful development of replacement gilts plays a critical role for sustainable swine production, whereas most gilts entering the breeding herd are culled at a young age. Recent advances in reproductive physiology revealed that the ovarian reserve could be considered as an important target of improving reproductive span. Therefore, in the present study, we hypothesized that ovarian follicle development and survival could be enhanced by dietary fiber. Currently there is no appropriate level of dietary fiber intake for growing replacement gilts despite the fact that dietary fiber, rather than starch, protein, or feeding allowance level, could improve the fertility of gilts. Results in the present study demonstrated that ovarian follicle development and survival were sensitive to dietary fiber levels. Our results shed light on the mechanisms underlying the beneficial effects of dietary fiber on the reproduction of sows and provided nutritional insights for enhancing the lifetime fertility of pigs by targeting the ovarian reserve.Ovarian follicle activation and survival were recently found to be controlled by nutrient sensors AMP-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR) and apoptosis related markers Caspase-3, Bax, and Bcl-2, yet their expression as regulated by dietary fiber remained uncertain for gilts. To investigate the effects of dietary fiber levels on ovarian follicle development, and the cellular molecular components related to follicle activation and survival of gilts, 76 gilts with similar bodyweight and age were fed four diets, including a corn-soybean meal based control diet, or other three diets to consume 50%, 75%, and 100% more dietary fiber than the control gilts at different experimental phases. Inulin and cellulose (1:4) were added to the corn-soybean meal basal diet to increase dietary fiber content. The growth traits, and the age, bodyweight, and backfat thickness at puberty were not affected by diets. The number of primordial follicles and total follicles per cubic centimeter of ovarian tissue linearly increased with dietary fiber level at day 30 of the experiment and at the 19th day of the 3rd estrous cycle, without negatively affecting the formation of antral follicle with diameter between 1–3 mm or larger than 3 mm. These changes were associated with altered phosphorylation of mTOR, S6, Extracellular regulated protein kinases 1/2 (ERK1/2) and AMPK, and mRNA expression of Caspase-3, Bax, and Bcl-2 in ovarian tissues. Collectively, this study demonstrated a beneficial effect of dietary fiber on the ovarian follicle reserve in gilts, which provides a basis for enhancing reproduction in the short- or long-term.

Implications of recent advances in reproductive physiology for reproductive management of goats

The control of reproduction in goats is interesting for technical reasons (synchronization of kiddings, adjustment to forage availability or to economy), and for genetic reasons (identification and dissemination of improved genotypes). The use of short-light rhythms leads to markedly increased production of semen per buck and prevents occurrence of a 'resting' season. Recent identification of a bulbourethral lipase in goat spermatozoa opens new perspectives in sperm preservation. Light plus 'short day' treatments also allow induction of out-of-season oestrous cycles and ovulations leading to enhanced fertility. Repeated use of eCG provokes the production of antibodies, delays the timing of ovulation and causes a reduction in fertility after fixed-time artificial insemination. All steps of embryo production, freezing and transfer are now controlled and allow the attainment of satisfactory numbers of kids born per donor female, which are compatible with the development of the technique for exchanging genotypes between countries. In vitro production of embryos allows high development rates to be achieved after in vitro maturation and fertilization of oocytes, and will ensure the production of synchronous populations of one-cell zygotes at the stage required by new biotechnologies.

Precision animal breeding

We accept that we are responsible for the quality of life of animals in our care. We accept that the activities of man affect all the living things with which we share this planet. But we are slow to realize that as a result we have a duty of care for all living things. That duty extends to the breeding of animals for which we are responsible. When animals are bred by man for a purpose, the aim should be to meet certain goals: to improve the precision with which breeding outcomes can be predicted; to avoid the introduction and advance of characteristics deleterious to well-being; and to manage genetic resources and diversity between and within populations as set out in the Convention on Biological Diversity. These goals are summed up in the phrase precision animal breeding. They should apply whether animals are bred as sources of usable products or services for medical or scientific research, for aesthetic or cultural considerations, or as pets. Modern molecular and quantitative genetics and advances in reproductive physiology provide the tools with which these goals can be met.

Current knowledge and future challenges in camelid reproduction

Reproductive biology research on camelids offers some interesting peculiarities and challenges to scientists and animal production specialists. The objective of this paper is to review camelid reproduction, advances in reproductive physiology and reproductive biotechnologies in camelids and discuss some areas for further research. In the female, the focus has been on understanding follicular dynamics. This has allowed development of synchronization and superovulation strategies to support embryo transfer technologies which are now commonly used in camels. Some advances have been achieved in preservation of embryos by vitrification. Fertilization, early embryo development and embryo signaling for maternal recognition of pregnancy are still not fully understood. New information on the interaction of the developing embryo and the endometrium may shed some light on this signaling as well as the mechanism of prevention of luteolysis. The presence of a seminal ovulation-inducing factor (OIF) was confirmed in llamas and alpacas. Chronology of oocytes maturation has been described. In vitro production of embryos has been achieved resulting in successful pregnancies and births in the dromedary. These techniques offer a new tool for the production and study of interspecies/cross-species embryos and their effect on pregnancy. Male reproductive function remains poorly studied. Semen preservation and artificial insemination still present many challenges and are not used in production at the moment. The involvement of climatic and nutritional conditions as well as the role of leptin in the regulation of reproductive function need to be evaluated.

Techniques and hazards of embryo manipulation and induction of parturition.

Abstract Extract Recent advances in reproductive physiology offer ways for exploiting superior, female cattle and for manipulating physiological events such as parturition. The techniques involved in these advances and their associated hazards are the subject of this review.

Lactogenic Hormones, Fetal Nutrition, and Lactation

This is the second of two volumes devoted to Problems of Human Reproduction that focus on recent advances in reproductive physiology. This book is intended to serve as a current review of studies of pituitary prolactin in primates and of the roles of lactogenic hormones (both placental and pituitary) in the nutrition of the fetus and newborn. Although the morphologic and biologic bases and the mechanisms of neural and endocrine control are still incompletely understood, a large body of information has recently become available. The editor has divided the volume into three main sections. The first covers the basic aspects of pituitary and placental lactogenic hormones: their isolation, purification, chemical and biologic characterization, physiologic and pharmacologic functions, and finally the various bioassays and immunoassays used for measurement of these hormones. The second section covers largely placental structure and the effects of chorionic somatomammotropin on laboratory primate and human maternal and

Advances in Reproductive Physiology

Advances in Teratology , vol 2, edited by D. H. M. Woolam, 306 pp, with illus, $16, New York: Logos Press, Academic Press, Inc., 1967. These books continue annual series begun last year. Reproductive physiology and teratology represent inclusive disciplines which embrace an immense variety of subjects, and in bothAdvances in Reproductive PhysiologyandAdvances in Teratologythe editor has decided to include articles dealing with a variety of topics, rather than a central theme. Thus, volume 2 ofAdvances in Reproductive Physiologycontains material on behavior, the Physiology of Courtship and Mating and Maternal Behavior in Rodents and Lagomorphs; items on gametes and reproductive tract functions, Formation of Egg in Domestic Chicken, The Biochemical and Physiological Relationships Between Gametes and Female Reproductive Tract, The Action of Oestrogens, and The Hormonal Interplay Controlling Egg-Implantation in Rat; and two articles discussing Growth of

Book reviews

Book reviewed in this article: The Origin of Genetics. A Mendel Source Book. Edited by Curt Stern and Eva R. Sherwood. San Francisco and London: W. H. Freeman and Company. 1966. Pp. 179. 18s. paper; 36s. cloth. Fundamental Genetica. Edited by Milan Sosna; selection and commentary by Jaroslav Kfiie‐neckf. Prague: Publishing House of the Czechoslovak Academy of Sciences; Brno: Moravian Museum; Oosterhout (N.B.), The Netherlands: Anthropological Publications. 1965. Pp. 400. Human Population Cytogenetics, by W. M. Court Brown. North‐Holland Publishing Company, Amsterdam: 196'7. Pp. xii+107. 40s. CIBA Foundation Study Group No. 25. Mongolisnz. In commemoration of Dr John Langdon Haydon Down. Edited by G. E. W. Wolstenholme and Ruth Porter. Published by J. and A. Churchill, Ltd. London. Pp. 99 + ix. 18s. Advances in Reproductive Physiology. Vol. I. Edited by Anne McLaren. London: Logos Press, and New York: Academic Press. 1966. 295 pp. Price 100s. Norrie's Disease. A Congenitd Progressive Oculo‐Acoustico‐Cerebral degeneration. By M. Warburg. Munksgaard: Copenhagen. 1966. Pp. 147. Price 65 Danish Kroner.