Journal of reproduction and fertility. Supplement最新文献

{"title":"Consequences of variation in interval from insemination to ovulation on fertilization in pigs.","authors":"B. Kemp, N. Soede","doi":"10.1530/biosciprocs.15.006","DOIUrl":"https://doi.org/10.1530/biosciprocs.15.006","url":null,"abstract":"This review describes effects of variation in the interval between insemination and ovulation on the fertilization process in the sow. Inseminations performed too early or too late relative to ovulation decrease litter size and especially farrowing rate. This effect can be explained to a large extent by the increase in the percentage of non-fertilized eggs, resulting in partial fertilization or no fertilization at all. No effects of variation in the interval from insemination to ovulation are found on the percentage of degenerate embryos. Only moderate effects are found on mean embryonic development and variation in embryonic development at day 5 after insemination. In general, insemination between 0 and 24 h before ovulation gives good fertilization results. Factors influencing the optimal interval from insemination to ovulation, such as number of sperm cells used for insemination, storage time of liquid semen and use of frozen semen, and sow factors such as parity and breed are discussed.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"47 1","pages":"79-89"},"PeriodicalIF":0.0,"publicationDate":"2020-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81421970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hypothalamic control of gonadotrophin and prolactin secretion in pigs.","authors":"R. Kraeling, C. Barb","doi":"10.1530/biosciprocs.13.001","DOIUrl":"https://doi.org/10.1530/biosciprocs.13.001","url":null,"abstract":"Interoceptive and exteroceptive stimuli detected by the central nervous system (CNS) are translated by the neuroendocrine system into signals which alter pituitary gland hormone function as depicted in Fig. 1 for gonadotrophin and prolactin secretion. The organization of this system has been thoroughly reviewed by Page (1988). Table 1 illustrates that components of the neuroendocrine— ovarian axis of the pig are functional before the onset of puberty at approximately 210 days of age and before the onset of oestrus that occurs 4-7 days after weaning. Post-partum sows in a state of prolonged anoestrus also respond to appropriate stimuli. Mechanisms which bring these components into the proper temporal relationships to generate oestrous cycles beginning at puberty and after weaning in sows reside in the CNS. The pattern of luteinizing hormone (LH) secretion, reflected by frequency, amplitude and duration of episodic release, is an important regulator of follicle development and ovulation in the primate, rat and sheep (Greenwald & Terranova, 1988). It is well established, at least in rats, that the pulsatile secretion of LH is controlled by a \"pulse generator\" of the hypothalamus and the preovulatory LH surge by a \"surge generator\" of the hypothalamus (Weiner el aL, 1988). These patterns of LH secretion presumably reflect the pattern of gonadotrophin-releasing hormone (Gn RH) released by neurosecretory neurones into the hypothalamo—hypophysial portal blood system (Goodman, 1988). Gonadal steroids and signals from other neurones modulate the frequency and amplitude of GnRH release. Prolactin secretion is also controlled by hypothalamic factors such as dopamine and thyroid-stimulating hormone-releasing hormone (TRH). This review will present evidence for control of gonadotrophin secretion by hypothalamic pulse and surge generators, and the role of ovarian steroids, various neurotransmitters and the endogenous opioid peptides (EOP; neural peptides with morphine-like biological activity) in modulating gonadotrophin and prolactin secretion during various physiological states in the pig.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"40 1","pages":"3-17"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73398004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Differentiation of sexual behaviour in pigs.","authors":"J. Ford","doi":"10.1530/biosciprocs.13.0022","DOIUrl":"https://doi.org/10.1530/biosciprocs.13.0022","url":null,"abstract":"Behaviour in pigs is sexually dimorphic as early as 1 month of age; mounting of penmates is observed more frequently for males than for females. This mounting reaches its highest frequency during the 2nd month of life and then declines to a low frequency in prepubertal pigs. During the prepubertal period (3-5 months of age), bipotentiality of sexual behaviour is apparent in boars because they will not only mount oestrous females but they are also receptive to mounts by older, mature boars. If males are castrated during neonatal development (first 2 months of life) and treated acutely with oestrogen during adulthood, they display sexual behaviour that is characteristic of females; i.e. show a selective preference to remain near mature boars in a choice test, are receptive to mounts by mature boars, and have a short latency to receptivity after contact with a mature boar. Males that are castrated at 6 months of age or later, or males that are castrated neonatally and treated chronically with oestrogen or testosterone during the prepubertal period, display significantly less female behaviour after acute oestrogen treatment than do males castrated neonatally. Additionally, exposure of females to elevated testosterone during early fetal development results in no detectable changes in oestrous behaviour as adults. These observations support the hypothesis that defeminization of sexual behaviour in boars occurs as a result of elevated testicular steroids during pubertal development. The limited data available on masculine sexual behaviour in pigs indicate an activational role for gonadal steroids with little evidence for true masculinization per se. After prolonged testosterone treatment of mature females or males that are castrated before puberty, considerable courtship and mounting behaviours are exhibited by these individuals when placed with oestrous females. Studies have not evaluated differential sensitivity of such animals to dosage or duration of testosterone treatment. Differentiation of sexual behaviour in boars therefore involves primarily a loss of sensitivity to display female-typical behaviours. Presently, pigs differ from other mammals that have been investigated because sexual differentiation of reproductive behaviour occurs during pubertal development and not during gestation.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"27 1","pages":"311-21"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82625101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of prolactin in the regulation of ovarian function in pigs.","authors":"L. Dusza, J. Tilton","doi":"10.1530/biosciprocs.13.003","DOIUrl":"https://doi.org/10.1530/biosciprocs.13.003","url":null,"abstract":"Prolactin has proliferative and differentiative effects on numerous types of. cells derived from several animal species (Nicoll, 1974). Among these various functions of prolactin is a role in the regulation of reproductive processes in mammals. In this paper we present the results of investigations concerning the influence of prolactin on the pig ovary, both in vitro and in vivo. Moreover, to present the progress of studies on mechanisms of prolactin action on ovarian cells, we include the results of studies performed on rats, in which the role of prolactin in the regulation of ovarian functions is well known.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"40 1","pages":"33-45"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72586580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Causes and consequences of early embryonic diversity in pigs.","authors":"W. F. Pope, S. Xie, D. M. Broermann, K. Nephew","doi":"10.1530/biosciprocs.13.0018","DOIUrl":"https://doi.org/10.1530/biosciprocs.13.0018","url":null,"abstract":"Within 14 h of ovulation, follicular development in gilts was skewed towards a majority of mature follicles, based on their endocrine milieu. Oocyte maturation was also skewed, with a majority of the oocytes being meiotically more developed than the rest. Similarly, the pattern of ovulation in gilts was such that 70% of the follicles ovulated during a short period of time, while most of the remaining 30% ovulated over a more protracted period. This majority/minority pattern of both oocyte development and ovulation paralleled the distribution of development among 1-cell litter-mate embryos. Furthermore, oocytes of follicles predicted to ovulate first became the more developed embryos, while oocytes from later ovulating follicles became the lesser developed embryos. When these later ovulating follicles were destroyed by electrocautery, diversity in embryonic morphology was reduced by Day 12, and this reduction resulted from elimination of the lesser developed embryos. Genetic factors might also affect embryonic disparity, as SLA (swine leucocyte antigen complex) haplotype affected cleavage rates of embryos from miniature pigs. Results of various embryo transfer experiments demonstrated that the more developed embryos within a litter have a competitive advantage for survival over their less developed contemporaries. These lesser developed embryos, however, were just as viable as the more developed embryos after asynchronous transfer to recipients displaying onset of oestrus 1 day after the donors. The more developed embryos within the litter, by synthesizing more oestradiol than the smaller embryos, advanced uterine secretions. As a result, the lesser developed embryos probably became more susceptible to this new environment and eventually died in an asynchronous environment. Therefore, we suggest that early embryonic mortality directly relates to sequences of oocyte and follicular maturation, as oogenesis directs embryogenesis.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"28 1","pages":"251-60"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80273066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advances in gender preselection in swine.","authors":"L. Johnson","doi":"10.1530/biosciprocs.15.0019","DOIUrl":"https://doi.org/10.1530/biosciprocs.15.0019","url":null,"abstract":"Gender preselection using isolated populations of X- and Y-chromosome bearing spermatozoa that have been separated on the basis of DNA content is currently possible in swine and other farm animals, as well as in humans. Semen from most livestock species can now be successfully separated into predominantly X or Y sperm populations before their use for intra-tubal insemination, deep-uterine insemination or for in vitro fertilization (IVF) to produce sexed offspring. Birth of progeny of the desired sex in cattle, sheep and swine under semi-practical conditions has successfully validated the sexing technology. Spermatozoa are separated on the basis of inherent differences in DNA content in the X- and Y-chromosome bearing sperm population using modified flow cytometry/cell sorting technology. Spermatozoa are stained with Hoechst 33342 which binds to the DNA in an amount proportional to the amount of DNA present in the individual spermatozoa. Over 300 animals from various species at several locations have been born using the USDA-Beltsville Sperm Sexing Technology for separating X and Y spermatozoa. Sex ratios are shifted from the normal 50:50 to 85 to 90% of one sex or the other. In swine, offspring have been born as the result of surgical intratubal insemination of separated spermatozoa and also from IVF and embryo transfer. At the present time, standard swine artificial insemination techniques are not optimized for use with the small numbers of flow cytometrically separated X or Y sperm populations. Cattle, swine and rabbit offspring have been reproduced through the second generation with normal morphology and reproductive function. Numerous improvements have been made in the sexing technology since it was first reported in 1989. Increasing the speed of the sexing process to make the application of the technology available to a larger segment of the livestock industry is paramount, even with insemination technology designed for small numbers of spermatozoa.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"19 1","pages":"255-66"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91156535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Basic physiology of follicular maturation in the pig.","authors":"G. Foxcroft, M. Hunter","doi":"10.1530/biosciprocs.12.001","DOIUrl":"https://doi.org/10.1530/biosciprocs.12.001","url":null,"abstract":"The pig is an excellent animal in which to study the control of folliculogenesis in a polytocous species, and particularly to examine the inter-relationships between follicles from the same animal. Follicle recruitment occurs from the proliferating pool, and various studies suggest that this recruitment occurs between Days 14 and 16 of the oestrous cycle. The growth of follicles selected for ovulation is associated with rapid atresia of smaller follicles and a block to their replacement in the proliferating pool. However, there is a considerable range in the morphological and biochemical development of the dominant follicles in the early follicular phase, suggesting that follicles are recruited at markedly different stages of development, or that recruitment continues into the follicular phase. A significant and predictable relationship has been established between follicular diameter and follicular fluid volume, and a comparison of these two characteristics demonstrates a gradual increase in follicular tissue volume as a proportion of total volume. Growth of follicles from 2 to 4 mm is associated with a proportional increase in granulosa cell numbers, but above 4 mm the relationship is very variable even in selected follicles that are steroidogenically active. Therefore, the number of granulosa cells cannot be used as an indicator of atresia in pig follicles. LH receptors are present in thecal tissue throughout development, reaching maximal levels on Day 20 of the oestrous cycle and declining on Day 21. Granulosa cells possess receptors for LH only in the later stages of maturation, and again these are maximal on Day 20. The pattern of steroidogenesis in pig follicles is consistent with the two-cell theory of steroidogenesis in that androgen produced by the theca is aromatized to oestrogen by the granulosa cells, However, in contrast to that of many other species, the theca of the pig also produces oestradiol in quantities comparable to those secreted by the granulosa. As with morphological development, the selected population of preovulatory follicles shows a considerable range of biochemical development and follicles of identical size may show great dissimilarity in follicular fluid steroid concentrations and LH binding. Androgen availability rather than aromatase activity appears to be the limiting factor for steroidogenesis. There are also several nonsteroidal factors which have been isolated from porcine tissue and play some role in follicular maturation. Although exogenous gonadotrophins are effective in promoting follicular development, other factors of extra- or intra-ovarian origin may limit follicular responsiveness to gonadotrophins.(ABSTRACT TRUNCATED AT 400 WORDS)","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"8 1","pages":"1-19"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75313070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Embryonic and fetal development in different genotypes in pigs.","authors":"Ford Sp","doi":"10.1530/biosciprocs.15.0012","DOIUrl":"https://doi.org/10.1530/biosciprocs.15.0012","url":null,"abstract":"It is widely accepted that uterine capacity, not ovulation rate, is the greatest restraint on litter size in pigs. Recently, the reproductive strategy(s) of the Chinese Meishan pig, a breed which farrows three to five more piglets per litter than US or European pig breeds, has come under intense scrutiny. It was initially determined that the Meishan female could farrow more viable piglets per litter than US or European pig breeds, with a uterine size and ovulation rate equivalent to those of less prolific breeds. It has become apparent that the Meishan conceptus exhibits a reduced trophectoderm mitotic rate during the preimplantation period, elongates from fewer cells and remains smaller throughout gestation compared with conceptuses from less prolific US or European pig breeds. This strategy by the Meishan conceptus for a lower growth rate results in a marked reduction in conceptus loss through day 18 of gestation compared with less prolific breeds. An additional strategy is required in the Meishan to allow the larger number of viable fetuses to survive after day 30 of gestation when uterine capacity becomes limiting. Our research has demonstrated that the rapid growth of the fetus in US pig breeds appears to require continued placental growth to increase the surface area for nutrient exchange. In contrast, the increased number of smaller Meishan fetuses achieve the same increase in placental efficiency by markedly increasing the density of placental blood vessels at the fetal-maternal interface. This proliferation of placental blood vessels obviates the need for marked increase in placental size.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"299 1","pages":"165-76"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89027564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regulation of uterine and conceptus secretory activity in the pig.","authors":"R. Simmen, F. Simmen","doi":"10.1530/biosciprocs.13.0020","DOIUrl":"https://doi.org/10.1530/biosciprocs.13.0020","url":null,"abstract":"Evidence is presented for the involvement of a number of specific uterine- and conceptus-derived proteins in endometrial differentiation and conceptus or fetal development. These secretory proteins include mitogens (insulin-like growth factor-I and -II, epidermal growth factor, uterine luminal fluid mitogen), binding and transport proteins (uteroferrin, insulin-like growth factor and retinol binding proteins, respectively), protease inhibitors (antileukoproteinase, plasmin/trypsin inhibitor), and trophoblastic specific proteins. Using immunological reagents and specific complementary DNA (cDNA) probes, the tissue origins of several of these proteins have now been identified. In addition, the temporal regulation of messenger RNA (mRNA) production for a number of these proteins has been elucidated. The results suggest that although circulating and locally produced steroid hormones may be involved in regulating the synthetic abilities of these tissues during pregnancy, other, as yet undefined, factors may also mediate these activities. In this paper we present a review of the current knowledge pertaining to the identity, physiological regulation and potential functions of pig maternal and conceptus secretory proteins during pregnancy.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"16 1","pages":"279-92"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90248800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sperm plasma membrane characteristics and boar semen fertility.","authors":"R. A. P. Harrison","doi":"10.1530/biosciprocs.15.0014","DOIUrl":"https://doi.org/10.1530/biosciprocs.15.0014","url":null,"abstract":"Much effort is being made to establish relationships between the molecular events that take place in spermatozoa under fertilizing conditions and actual sperm function during fertilization. During capacitation, the process that 'primes' spermatozoa for interaction with the egg, components of the sperm's environment, notably bicarbonate, provoke various specific changes in the architecture and functioning of the sperm plasma membrane in a large number of cells. The individual changes have been found to proceed on different time scales, and may therefore represent sequential stages in the capacitation process. However, each change takes place at different rates in individual cells, revealing considerable functional heterogeneity within the sperm population. Recent work on membrane changes provoked by cooling has indicated similarities with capacitational changes. The effect of cooling may therefore be to induce premature capacitation (and destabilization). Such an effect would greatly compromise sperm fertilizing potential. A pig sperm-egg interaction model was used to examine quantitative details of zona binding and zona penetrating abilities within capacitated sperm populations, and sperm behaviour was found not to accord with generally held beliefs. In particular, individual spermatozoa that have bound to the zona pellucida show great variation in the delay before penetrating: no evidence has been found for a specially competent subgroup. Even in sperm samples incubated to undergo maximal capacitational membrane changes, cells with actual penetrating potential represent less than 15% of the total number that attach initially to the zona pellucida. Thus detection of capacitational membrane changes appears greatly to overestimate zona penetrating capability. Future studies linking sperm membrane characteristics with semen fertility in the field will need to consider differences between in vitro and in vivo conditions. The need for survival in the female tract may require much slower sperm responses than are considered optimal for in vitro fertilization.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"1 1","pages":"195-211"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90337707","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}