Journal of reproduction and fertility. Supplement最新文献

{"title":"Nutrition and sow prolificacy.","authors":"F. Aherne, R. Kirkwood","doi":"10.1530/biosciprocs.12.0013","DOIUrl":"https://doi.org/10.1530/biosciprocs.12.0013","url":null,"abstract":"Prolificacy has been defined as the number of viable piglets produced per year or per breeding lifetime. Prolificacy is influenced by age at first successful mating, ovulation rate and embryo survival at each mating, number of live born, viable pigs and the sow's ability to be successfully remated at regular intervals. It is concluded that under normal conditions of feeding and management nutrition will have a minimal influence on gilt prolificacy. However, to gain the advantages of a slightly younger age at puberty, maximal ovulation rate and an adequate fat cover (if only to ensure against subsequent poor management), gilts should be fed ad libitum up to the time of mating. Long-term performance is best served by minimizing fluctuations in live weight and fat reserves, so avoiding extremes of body condition and subsequent poor performance. This is achieved by small controlled increases in sow body weight during pregnancy and feeding to appetite for restricted periods each day during lactation. Assuming the sow has not achieved a very poor condition during lactation, feeding level during pregnancy will have little effect on numbers of piglets born, and only a limited influence on piglet birthweights. The conclusion that piglet birth weights will be influenced more by total pregnancy feed intake than pattern of feed distribution is unchallenged. Lactation feed intake is shown to have marked effects on the post-weaning performance, low-level feeding leading to an extension of the remating interval and possibly increasing embryo mortality. No benefit of high-level feeding after weaning is demonstrable, except possibly in primiparous sows or sows having suffered an extreme loss of liveweight and body condition during the previous lactation.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"29 1","pages":"169-83"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86060133","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":"Mechanisms mediating nutritional effects on embryonic survival in pigs.","authors":"G. Foxcroft","doi":"10.1530/biosciprocs.15.004","DOIUrl":"https://doi.org/10.1530/biosciprocs.15.004","url":null,"abstract":"The inconsistency of data from experiments designed to show nutritional effects on embryonic survival is perplexing. However, a number of experimental models have provided some insight into the mechanisms that potentially mediate interactions between nutrition, metabolic state and embryonic survival. The developing ovarian follicle provides the maturational environment for the oocyte, and differences in follicular maturation are associated with differences in the ability of these follicles to support oocyte maturation. In turn, the rate of oocyte maturation and the maturational state of the oocyte immediately before ovulation may contribute to differences in embryonic survival. Therefore, evidence that nutritionally induced differences in metabolic state affect follicular development and the maturational state of the oocyte in the late follicular phase may constitute a mechanism by which nutrition affects the very early stages of conceptus development. Once ovulation occurs, the process of fertilization and early cleavage occurs in the environment of the oviduct. Nutritional state might affect the secretory and motile activity of the oviduct both directly, by influencing the physiology of the oviductal cells, or indirectly by affecting the secretion of key regulatory hormones. Thus evidence for nutritionally dependent effects on plasma progesterone concentrations in early pregnancy and associations with differences in embryonic survival may be partly mediated at the oviductal stage of development. Nutritional effects on circulating progesterone concentrations may also affect the uterine environment. However, the metabolic state of the gilt or sow, or specific nutrients in the diet, may directly affect the integrity of the endometrium and thus affect embryonic survival at this stage of development.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"210 1","pages":"47-61"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76133356","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":"Optimizing semen production for artificial insemination in swine.","authors":"B. Colenbrander, H. Feitsma, H. Grooten","doi":"10.1530/biosciprocs.14.0014","DOIUrl":"https://doi.org/10.1530/biosciprocs.14.0014","url":null,"abstract":"Efficient production of high quality semen is of major importance to artificial insemination (AI) organizations. The semen produced should be free of contagious organisms, be of high quality, have good storage properties, fertilizing capacity and be of high genetic value. The best approach to prevent the spreading of microorganisms via semen in the process of AI is to collect semen from boars free from specific diseases, for example pseudorabies virus or leptospirosis. Antibiotics are added to the semen to suppress proliferation of microorganisms or even reduce their number. Sperm production is influenced by many factors such as season, collection frequency, breed and age. The average number of sperm cells produced per boar per week can vary more than 30% within one AI station, depending on the breed. Boar selection and boar management markedly influence the efficiency of sperm production. Sperm quality should be evaluated by fertility results obtained at breeding farms related to both farrowing rate and litter size to ensure a good quality monitoring system. A quality control system should be established to provide maximum reliability to customers.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"54 1","pages":"207-15"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77610520","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":"Establishment of pregnancy and its immunological implications in the pig.","authors":"E. Koch","doi":"10.1530/biosciprocs.12.005","DOIUrl":"https://doi.org/10.1530/biosciprocs.12.005","url":null,"abstract":"The consideration of the fetus as a semi-allograft by virtue of its paternally inherited histocompatibility antigens is generally accepted. Many hypotheses have been put forward to explain the immunological acceptance of the conceptus by the maternal immune system, but no single theory has proved to be adequate. Most studies so far have been carried out with laboratory rodents and men but corresponding investigations of farm animals and especially the pig are limited. Because striking differences exist between various species, e.g. with respect to the type of placentation, litter size, gestation time and hormone production, the relevance of studies in rodents and men for other species has to be established. This review examines, in the context of available information from other mammalian systems, whether the pig conceptus expresses and presents antigens to the maternal immune system, to what extent the sow recognizes and responds to these antigens, and, in the event of recognition, the mechanisms by which the conceptus avoids and exploits the consequences of histoincompatibility.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"14 1","pages":"65-81"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76839796","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":"Effects of semen components on ovulation and fertilization.","authors":"D. Waberski","doi":"10.1530/biosciprocs.15.008","DOIUrl":"https://doi.org/10.1530/biosciprocs.15.008","url":null,"abstract":"In pigs, transcervical infusion of seminal plasma at the onset of oestrus advances ovulation and thus improves the chance of gametes meeting during their full fertilizing competence. An animal model that allows single uterine horn infusion was used in combination with transcutaneous sonographic monitoring of ovaries. Preparative surgery involved the detachment of one uterine horn from the corpus, leaving the caudal end open to the peritoneal cavity but sealing the corpus wound. Transcervical infusion of 100 ml seminal plasma immediately after the detection of oestrus advanced ovulation by between 8 and 14 h on the ipsilateral ovary adjacent to the infused horn compared with the contralateral ovary. In addition, the seminal plasma infusion did not influence the LH profile compared with uterine infusion of PBS. This finding indicates that the effect is mediated by a local mechanism in the female genital tract. The advancement of ovulation depends on the time of infusion early in oestrus and is more pronounced in gilts exhibiting a long interval between the onset of oestrus and spontaneous ovulation compared with early ovulators. At 24 h after the detection of oestrus, seminal plasma was ineffective. Apparently, seminal plasma does not affect maturation and fertilizing competence of oocytes. The activity resides in a low molecular mass protein fraction and, to a far lesser extent, in seminal oestrogens. Further characterization of the active components may allow a practical application in AI.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"319 1","pages":"105-9"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75040248","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":"Oviductal regulation of fertilization and early embryonic development.","authors":"W. Buhi, I. M. Alvarez, A. Kouba","doi":"10.1530/biosciprocs.15.0021","DOIUrl":"https://doi.org/10.1530/biosciprocs.15.0021","url":null,"abstract":"During the period of late follicular development and the first four days of the oestrous cycle, the oviduct occupies a central role in the establishment of pregnancy. Oviductal function is regarded as being either 'passive' or biologically active, providing an environment that sustains and enhances fertilization and early cleavage-stage embryonic development. Recent reports have focused on this microenvironment and shown that ovarian steroids induce marked morphological, physiological and biochemical changes. Alterations include changes in the biosynthetic activity and release of macromolecules by the oviductal epithelium which become part of the luminal microenvironment. Furthermore, both regional and temporal differences in activity and protein production occur through hormonal changes during the oestrous cycle and early pregnancy. Studies on identification, characterization and regulation of several proteins synthesized de novo have indicated oocyte-oviduct and embryo-oviduct interactions. However, the identification of oviduct-derived proteins, their regulation and their potential function in vivo needs to be examined. Studies in other species also suggest roles for growth factors in early embryonic development, but little information is available for the pig. We propose that ovarian hormones control changes in synthetic activity, synthesis of some oviduct-derived proteins and the presence of specific factors in the luminal microenvironment which sustain and enhance fertilization and early cleavage-stage embryonic development.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"6 1","pages":"285-300"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79651722","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 and action of gonadotrophins in pigs.","authors":"K. Esbenshade, A. Ziecik, J. Britt","doi":"10.1530/biosciprocs.13.002","DOIUrl":"https://doi.org/10.1530/biosciprocs.13.002","url":null,"abstract":"Gonadotrophins, synthesized and secreted from the basophils of the adenohypophysis, bind to various target cells and elicit a wide variety of responses. Specific receptors for gonadotrophins have been found on plasma membranes of thecal, granulosa, luteal, endometrial and myometrial cells in the female and on Leydig and Sertoli cells in the male. Gonadotrophins exert their effects through various intracellular second messengers and control biosynthetic pathways of steroid production in responsive cells. Gonadotrophins stimulate growth and development of antral follicles in the female. PMSG, FSH, or hourly pulses of GnRH, LH or a combination of LH and FSH induce follicular growth and development in prepubertal gilts and lactating and(or) anoestrous sows. The number of follicles that develop to ovulatory size in response to PMSG and FSH is dose-dependent, but pulsatile treatment with GnRH or gonadotrophins results in an ovulation rate similar to that observed during spontaneous follicular development. Endocrine changes resulting from treatments that induce follicular growth and development are similar to those observed during the follicular phase of the oestrous cycle. Hypophysectomy, hypophysial-stalk transection, active and passive immunization against GnRH, and active immunization against LH impair reproduction by interfering with normal follicular development in the female. Gonadotrophins, administered to gilts as repeated injections of whole pituitary extract or as pulses of GnRH agonist, do not stimulate follicular growth in gilts actively immunized against GnRH. Similarly, PMSG is ineffective in inducing follicular growth and development in gilts actively immunized against GnRH and after hypophysectomy or hypophysial-stalk transection. In contrast, PMSG is effective for inducing follicular development in hypophysial stalk-transected pigs when pulses of GnRH are given simultaneously with the PMSG. These results suggest that agents in addition to the gonadotrophins are required for the full complement of follicular growth, recruitment and development. Insulin, growth factors and steroids modify the response of cells to the gonadotrophins and may mediate these effects. Other possibilities include substances released from the pituitary gland or GnRH-like peptide(s) produced by the ovary that act as autocrine or paracrine regulators of follicular development. Gonadotrophins stimulate testicular function in the male. Active immunization of mature boars against GnRH or LH results in testicular atrophy, depressed steroidogenic and spermatogenic functions and impaired libido. Treatment of boars immunized against GnRH with hCG restores steroidogenic function of the testes as evidenced by testosterone production. Gonadotrophins also exert an influence in the central nervous system. Administration of hCG intramuscularly or intracranially blocks the oestrogen-induced preovulatory LH surge in ovariectomized pigs via a short loop feedback control mechanism","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"21 1","pages":"19-32"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82772333","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":"Nutritional strategies to optimize reproduction in pigs.","authors":"D. J. A. Cole","doi":"10.1530/biosciprocs.13.005","DOIUrl":"https://doi.org/10.1530/biosciprocs.13.005","url":null,"abstract":"The relationships between nutrition and reproduction have been reviewed on many occasions (e.g. Cole, 1982; Hardy & Frape, 1982; Aherne & Kirkwood, 1985). The approach adopted in this paper is somewhat different in that while it examines, in broad terms, the influences which may be involved within the reproductive cycle and their role in long term strategies, it also seeks to move towards a particular strategy. The development of a nutritional strategy necessitates the clear identification of objectives followed by the use of sound scientific principles as a basis for realistic application. This may result in some aspect of the science or practice completely outweighing the other or it may result in a compromise between the two. For example, meat is virtually the total saleable product from pigs and considerable emphasis is placed on the production of the pig to slaughter weight. Consequently, no attention is given at this stage to treating the small pig as a potential breeding animal. It is fortuitous that the nutrition of meat pigs gives an adequate basis for future breeding and it is likely that reproduction will be optimized in the early stages (e.g. the gilt litter) by more attention being paid to the tactics to be adopted around puberty and first mating. However, strategies for sow nutrition imply attention to long term reproductive performance. Consequently, when examining the influences of nutrition at different stages of the reproductive cycle it is important to consider their effect on the whole breeding life-time. In this context, body condition and how it is influenced by the level and pattern of supply of energy and nutrients is generally considered of key importance. Relationships exist between the different phases of the reproductive cycle and their influence needs to be accommodated in developing an appropriate strategy.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"8 1","pages":"67-82"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91159907","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":"Fertilization of pig eggs in vivo and in vitro.","authors":"R. Hunter","doi":"10.1530/biosciprocs.13.0015","DOIUrl":"https://doi.org/10.1530/biosciprocs.13.0015","url":null,"abstract":"The objective of this review is to set some of the problems associated with attempted in-vitro fertilization of pig eggs in a perspective drawn from the results of studies in live animals. Accordingly, the first part of the paper summarizes a variety of classical and more recent experiments performed in viva whilst the second part examines in-vitro observations and the nature of the experimental conditions imposed. A more general discussion follows in which suggestions are made ffir future work. It should be emphasized that this review does not attempt an exhaustive citation of relevant publications. None the less, it is hoped that sufficient references are given to provide access to the main body ofliterature available up to December 1988. Taken in conjunction with previous reviews having a different orientation (Hancock, 1962; Alanko, 1973; Baker & Polge, 1976; Polge, 1978; Einarsson, 1980: Hunter, 1982), a majority of studies bearing on the process of fertilization in pigs should become accessible.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"14 1","pages":"211-26"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80190541","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":"Molecular approaches to improved pig fertility.","authors":"Max F. Rothschild, L. Messer, A. Vincent","doi":"10.1530/biosciprocs.15.0016","DOIUrl":"https://doi.org/10.1530/biosciprocs.15.0016","url":null,"abstract":"Geneticists have made limited progress in improving reproductive traits in pigs through traditional selection and crossbreeding systems. Recent advances in molecular genetics and the human genome project have allowed progress in gene identification and gene mapping in pigs. The pig genetic linkage map now has over 1700 genetic markers, and about 200 of these are genes. Furthermore, comparative genomic maps are improving and are becoming useful tools. Molecular approaches such as candidate gene identification and genomic scans permit new genes and chromosomal regions to be discovered which may influence reproduction. One significant finding is that the oestrogen receptor locus (ESR) is associated with increased litter size. Differences between female Chinese pig ESR BB and AA homozygotes have averaged 2.3 pigs born alive for first parity, and in commercial Large White crosses the differences are about 0.9 pigs per litter. Additional new genes have been discovered which may significantly affect litter size. Initial genome scans have revealed that there may be a gene or genes influencing ovulation rate and litter size on chromosome 8. Approaches such as positional comparative candidate gene analysis and eventually positional cloning will probably identify the genes controlling reproduction in pigs.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"35 1","pages":"227-36"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74833534","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}