Pub Date : 2020-10-12DOI: 10.1530/biosciprocs.18.0019
K. Brüssow, F. Schneider, W. Kanitz, J. Rátky, J. Kauffold, M. Wahner
A technology that allows for manipulating of oestrus and ovulation, and would then also allow for fixed-time insemination, can be of great benefit for swine farms that operate using sow batch management due, at least in part, to savings in labour and the production of large batches of evenly developed pigs. Thanks to the current knowledge on endocrine regulation of follicle development and ovulation, and the availability of numerous reproductively active substances such a technology is now available. It covers procedures for synchronising oestrus based on the use of altrenogest in gilts and of batch-wise weaning in sows, for stimulating follicle development using eCG and for inducing of ovulation using hCG or LH as well as GnRH analogues. While the procedures for oestrus synchronisation stand alone, other procedures require additional treatments. If fixed-time insemination is the goal, oestrus needs to be synchronised and follicular development and ovulation induced by the use of GnRH analogues and hCG with ovulation occurring within 36-42 hrs. It is a general recommendation to inseminate those animals twice, i.e. 24 and 40 hrs after ovulation induction. However, the aforementioned technology requires healthy animals and a solid management and cannot be used to compensate for poor management.
{"title":"Studies on fixed-time ovulation induction in the pig.","authors":"K. Brüssow, F. Schneider, W. Kanitz, J. Rátky, J. Kauffold, M. Wahner","doi":"10.1530/biosciprocs.18.0019","DOIUrl":"https://doi.org/10.1530/biosciprocs.18.0019","url":null,"abstract":"A technology that allows for manipulating of oestrus and ovulation, and would then also allow for fixed-time insemination, can be of great benefit for swine farms that operate using sow batch management due, at least in part, to savings in labour and the production of large batches of evenly developed pigs. Thanks to the current knowledge on endocrine regulation of follicle development and ovulation, and the availability of numerous reproductively active substances such a technology is now available. It covers procedures for synchronising oestrus based on the use of altrenogest in gilts and of batch-wise weaning in sows, for stimulating follicle development using eCG and for inducing of ovulation using hCG or LH as well as GnRH analogues. While the procedures for oestrus synchronisation stand alone, other procedures require additional treatments. If fixed-time insemination is the goal, oestrus needs to be synchronised and follicular development and ovulation induced by the use of GnRH analogues and hCG with ovulation occurring within 36-42 hrs. It is a general recommendation to inseminate those animals twice, i.e. 24 and 40 hrs after ovulation induction. However, the aforementioned technology requires healthy animals and a solid management and cannot be used to compensate for poor management.","PeriodicalId":87420,"journal":{"name":"Society of Reproduction and Fertility supplement","volume":"66 1","pages":"187-95"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47300346","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}
Pub Date : 2020-10-12DOI: 10.1530/biosciprocs.18.0007
A. K. Olesen, C. Hansen
Artificial insemination of sows is an effective method for intensive use of high breeding value boars. In sows, intracervical insemination (ICI) using 2 to 3 billion spermatozoa is an established method worldwide, resulting in aconsistently high fertility (Watson et al. 2002). Using intrauterine insemination, the number of spermatozoa per insemination can be reduced even further. In intrauterine insemination (IUI), the tip of the catheter is placed in the corpus uteri depositing the semen even closer to the site of fertilization in the oviduct (Vazquez et a/. 2008). If IUI can be performed aseasily and efficiently as ICI, this will result in more semen doses per boar. This will allow a stronger selection among boars, and lower the costs per dose. This study investigated the effect on fertility, when reducing the amount of sperm per dose using IUI. A total of 9272 multiparous Danish Landrace x Large White crossbred sows from seven Danish commercial herds were randomly distributed into three groups as shown in table 1. All sows were inseminated using heterospermic semen from Danish Duroc boars. Semen was collected using the gloved hand method collecting the whole ejaculate. Semen quality was evaluated using subjective microscopic motility score. Semen concentration was measured using NucleoCounter SP100. Semen was extended using EDTA boar semen extender. The same batch of semen comprising semen from 6 to 10 boars was used in all three groups in each herd. One dose from each batch was analysed for content of sperm per dose using SP100.
{"title":"Intrauterine insemination of sows by using a two-chamber semen bag system.","authors":"A. K. Olesen, C. Hansen","doi":"10.1530/biosciprocs.18.0007","DOIUrl":"https://doi.org/10.1530/biosciprocs.18.0007","url":null,"abstract":"Artificial insemination of sows is an effective method for intensive use of high breeding value boars. In sows, intracervical insemination (ICI) using 2 to 3 billion spermatozoa is an established method worldwide, resulting in aconsistently high fertility (Watson et al. 2002). Using intrauterine insemination, the number of spermatozoa per insemination can be reduced even further. In intrauterine insemination (IUI), the tip of the catheter is placed in the corpus uteri depositing the semen even closer to the site of fertilization in the oviduct (Vazquez et a/. 2008). If IUI can be performed aseasily and efficiently as ICI, this will result in more semen doses per boar. This will allow a stronger selection among boars, and lower the costs per dose. This study investigated the effect on fertility, when reducing the amount of sperm per dose using IUI. A total of 9272 multiparous Danish Landrace x Large White crossbred sows from seven Danish commercial herds were randomly distributed into three groups as shown in table 1. All sows were inseminated using heterospermic semen from Danish Duroc boars. Semen was collected using the gloved hand method collecting the whole ejaculate. Semen quality was evaluated using subjective microscopic motility score. Semen concentration was measured using NucleoCounter SP100. Semen was extended using EDTA boar semen extender. The same batch of semen comprising semen from 6 to 10 boars was used in all three groups in each herd. One dose from each batch was analysed for content of sperm per dose using SP100.","PeriodicalId":87420,"journal":{"name":"Society of Reproduction and Fertility supplement","volume":"66 1","pages":"81-2"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48688411","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}
Pub Date : 2020-10-12DOI: 10.1530/biosciprocs.18.0010
S. Onteru, J. Ross, M. Rothschild
The reproductive performance of the sow is one of the key factors affecting production profitability of the pig industry. Reproductive traits are in general, lowly heritable, and with reliable markers, they can be used to enhance current selection procedures for improvement of these traits. To find potential markers, large scale quantitative trait loci (QTL) and candidate gene studies have been conducted for reproductive traits. The present review discusses QTL and candidate gene discovery, large scale SNP association studies, gene expression profiling and discovery of miRNA regulation of pig reproductive tissues. Many QTL have been found for reproduction traits and a limited number of useful genes (e.g.: ESR1, PRLR, FSHB, EPOR and RBP4) have been found to have significant associations with reproductive traits. Expression studies with reproductive tissues have revealed differential expression within a few gene networks which need further mapping and association analyses to select prospective gene markers. The near completion of the pig genome sequence and the development of high density SNP chips will allow for large scale SNP association studies for pig reproductive traits in the future. Collection of appropriate phenotypes in large numbers and in broad populations representative of the swine industry are required if such genomic studies will ultimately be successful.
{"title":"The role of gene discovery, QTL analyses and gene expression in reproductive traits in the pig.","authors":"S. Onteru, J. Ross, M. Rothschild","doi":"10.1530/biosciprocs.18.0010","DOIUrl":"https://doi.org/10.1530/biosciprocs.18.0010","url":null,"abstract":"The reproductive performance of the sow is one of the key factors affecting production profitability of the pig industry. Reproductive traits are in general, lowly heritable, and with reliable markers, they can be used to enhance current selection procedures for improvement of these traits. To find potential markers, large scale quantitative trait loci (QTL) and candidate gene studies have been conducted for reproductive traits. The present review discusses QTL and candidate gene discovery, large scale SNP association studies, gene expression profiling and discovery of miRNA regulation of pig reproductive tissues. Many QTL have been found for reproduction traits and a limited number of useful genes (e.g.: ESR1, PRLR, FSHB, EPOR and RBP4) have been found to have significant associations with reproductive traits. Expression studies with reproductive tissues have revealed differential expression within a few gene networks which need further mapping and association analyses to select prospective gene markers. The near completion of the pig genome sequence and the development of high density SNP chips will allow for large scale SNP association studies for pig reproductive traits in the future. Collection of appropriate phenotypes in large numbers and in broad populations representative of the swine industry are required if such genomic studies will ultimately be successful.","PeriodicalId":87420,"journal":{"name":"Society of Reproduction and Fertility supplement","volume":"66 1","pages":"87-102"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42728763","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}
Pub Date : 2020-10-12DOI: 10.1530/biosciprocs.18.0027
D. Eborn, D. Davis, D. Grieger
The expression of the transcription factors Nanog, Sox-2 and Oct-4 is required for maintaining the inner cell massand ensuing epiblast of the developing mouse embryo as well as pluripotency of embryonic stem cells in culture. Nanog and Oct-4 are down regulated about the time of gastrulation (Rosner et al. 1990, Chambers et al. 2003) whereas Sox-2 expression is observed in other tissues including the developing nervous system (Avilion et al. 2003). In embryonic stem cells, these factors suppress differentiation and promote self-renewal by forming an autoregulatory and feedforward network. The expression pattern of these markers in farm animal species is not well characterized and may differ from that of the mouse (Degrelle et al. 2005). Therefore, we have partially cloned the porcine Oct-4, Nanog and Sox-2 transcripts and characterized their expression in day-10, -12, -15, and -17 embryonic and extraembryonic tissues as well as endometrium, myometrium, placenta and fetal liver at day 40 of pregnancy (day 0 is the onset of estrus). Embryos were flushed from sows 10, 12, 15, and 17 days post-insemination. Day-10 and -12 embryos were processed as whole conceptuses. Day-15 and -17 embryonic tissue (embryonic disk) was separated by closely trimming the adjacent extraembryonic tissue (proximal extraembryonic) with a scalpel using a stereo-microscope (5 to 50X). Additional extraembryonic tissue (distal extraembryonic) was collected after removal of the embryonic disks. Total RNA was isolated using RNeasy Mini or RNeasy Micro Kits (Qiagen; Valencia, CA) according to manufacture's instructions. Sequence for each transcription factor was obtained by full-length RNA ligase-mediated rapid amplification with either the RLM-Race (Ambion; Austin TX) or GeneRacer (Invitrogen; Carlsbad CA) kits according to manufacture's instructions. Total RNA was reverse transcribed and real-time PCR was peformed using TaqMan probe-based assays (Applied Biosystems; Foster City CA). Threshold values were normalized using 18s ribosomal RNA as the endogenous control. Using the adjusted threshold values, tissue means were compared by the GLM procedure of SAS(SASInstitute Inc.; Cary NC) and pair-wise comparisons were made between tissues. For each gene, the tissue with the lowest adjusted threshold value was designated as the reference tissue. Relative expression differences were calculated by taking the difference in threshold values with the reference tissue and raising it by 2. The coding sequence for porcine Nanog (Genbank: DQ447201) including 452 base pairs of the Nanog promoter, and partial coding sequences of Oct-4 and Sox-2 were obtained. The homeodomain and c-terminal tryptophan repeats are highly conserved in porcine Nanog compared to the mouse, human and bovine. In the promoter, the highly conserved Octamer and Sox binding sequences are also present. Oct-4 and Sox-2 expression (see Table 1) was lowest in day-40 tissues except for fetal liver which was 20 and 71 fold, respe
转录因子Nanog, Sox-2和Oct-4的表达是维持发育中的小鼠胚胎的内细胞群和随后的外胚层以及胚胎干细胞培养的多能性所必需的。Nanog和Oct-4在原肠胚形成时下调(Rosner et al. 1990, Chambers et al. 2003)，而在发育中的神经系统等其他组织中也观察到Sox-2的表达(Avilion et al. 2003)。在胚胎干细胞中，这些因子通过形成一个自我调节和前馈网络来抑制分化并促进自我更新。这些标记物在农场动物物种中的表达模式尚未得到很好的表征，可能与小鼠的表达模式不同(Degrelle et al. 2005)。因此，我们部分克隆了猪Oct-4、Nanog和ox-2转录本，并鉴定了它们在妊娠第10天、第12天、第15天和第17天的胚胎和胚胎外组织以及子宫内膜、子宫肌层、胎盘和胎儿肝脏(第0天为发情开始)中的表达。胚胎在受精后10、12、15和17天从母猪身上冲洗。第10天和第12天的胚胎作为整个概念处理。在立体显微镜下(5 ~ 50倍)，用手术刀紧切相邻的胚外组织(近端胚外组织)，分离第15天和第17天的胚胎组织(胚盘)。在去除胚盘后收集额外的胚外组织(远端胚外组织)。总RNA采用RNeasy Mini或RNeasy Micro kit (Qiagen;瓦伦西亚，CA)，根据制造商的说明。每个转录因子的序列通过RLM-Race (Ambion;Austin TX)或GeneRacer (Invitrogen;卡尔斯巴德CA)试剂盒根据制造商的说明。逆转录总RNA，利用TaqMan探针进行实时PCR检测(Applied Biosystems;福斯特市CA)。以18s核糖体RNA作为内源对照，将阈值归一化。使用调整后的阈值，组织均值采用SAS(SASInstitute Inc.)的GLM程序进行比较;Cary NC)和组织间两两比较。对于每个基因，选取调整阈值最低的组织作为参比组织。相对表达差异的计算方法是取与参比组织的阈值之差，将其提高2。获得了猪Nanog (Genbank: DQ447201)启动子452个碱基对的编码序列，以及Oct-4和Sox-2的部分编码序列。与小鼠、人类和牛相比，猪Nanog的同源结构域和c端色氨酸重复序列高度保守。在启动子中，高度保守的Octamer和Sox结合序列也存在。Oct-4和Sox-2的表达(见表1)在第40天的组织中最低，但胎儿肝脏分别比子宫内膜高20倍和71倍。Nanog RNA的表达模式与Oct-4和Sox-2不同。与第15天的远端胚胎外组织相比，第40天的组织表现出最高的Nanog表达，包括子宫内膜(7倍)、胎肝(27倍)、胎盘(40倍)和肌层(72倍)。这些转录因子在胎儿肝脏中的表达可能表明存在干细胞群
{"title":"Cloning and expression of pluripotent factors around the time of gastrulation in the porcine conceptus.","authors":"D. Eborn, D. Davis, D. Grieger","doi":"10.1530/biosciprocs.18.0027","DOIUrl":"https://doi.org/10.1530/biosciprocs.18.0027","url":null,"abstract":"The expression of the transcription factors Nanog, Sox-2 and Oct-4 is required for maintaining the inner cell massand ensuing epiblast of the developing mouse embryo as well as pluripotency of embryonic stem cells in culture. Nanog and Oct-4 are down regulated about the time of gastrulation (Rosner et al. 1990, Chambers et al. 2003) whereas Sox-2 expression is observed in other tissues including the developing nervous system (Avilion et al. 2003). In embryonic stem cells, these factors suppress differentiation and promote self-renewal by forming an autoregulatory and feedforward network. The expression pattern of these markers in farm animal species is not well characterized and may differ from that of the mouse (Degrelle et al. 2005). Therefore, we have partially cloned the porcine Oct-4, Nanog and Sox-2 transcripts and characterized their expression in day-10, -12, -15, and -17 embryonic and extraembryonic tissues as well as endometrium, myometrium, placenta and fetal liver at day 40 of pregnancy (day 0 is the onset of estrus). Embryos were flushed from sows 10, 12, 15, and 17 days post-insemination. Day-10 and -12 embryos were processed as whole conceptuses. Day-15 and -17 embryonic tissue (embryonic disk) was separated by closely trimming the adjacent extraembryonic tissue (proximal extraembryonic) with a scalpel using a stereo-microscope (5 to 50X). Additional extraembryonic tissue (distal extraembryonic) was collected after removal of the embryonic disks. Total RNA was isolated using RNeasy Mini or RNeasy Micro Kits (Qiagen; Valencia, CA) according to manufacture's instructions. Sequence for each transcription factor was obtained by full-length RNA ligase-mediated rapid amplification with either the RLM-Race (Ambion; Austin TX) or GeneRacer (Invitrogen; Carlsbad CA) kits according to manufacture's instructions. Total RNA was reverse transcribed and real-time PCR was peformed using TaqMan probe-based assays (Applied Biosystems; Foster City CA). Threshold values were normalized using 18s ribosomal RNA as the endogenous control. Using the adjusted threshold values, tissue means were compared by the GLM procedure of SAS(SASInstitute Inc.; Cary NC) and pair-wise comparisons were made between tissues. For each gene, the tissue with the lowest adjusted threshold value was designated as the reference tissue. Relative expression differences were calculated by taking the difference in threshold values with the reference tissue and raising it by 2. The coding sequence for porcine Nanog (Genbank: DQ447201) including 452 base pairs of the Nanog promoter, and partial coding sequences of Oct-4 and Sox-2 were obtained. The homeodomain and c-terminal tryptophan repeats are highly conserved in porcine Nanog compared to the mouse, human and bovine. In the promoter, the highly conserved Octamer and Sox binding sequences are also present. Oct-4 and Sox-2 expression (see Table 1) was lowest in day-40 tissues except for fetal liver which was 20 and 71 fold, respe","PeriodicalId":87420,"journal":{"name":"Society of Reproduction and Fertility supplement","volume":"66 1","pages":"211-2"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44834626","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}
Pub Date : 2020-10-12DOI: 10.1530/biosciprocs.18.0003
I. Parrilla, J. M. Vázquez, I. Caballero, M. Gil, M. Hernandez, J. Roca, X. Lucas, E. Martinez
Despite the great potential of sperm technologies such as sperm cryopreservation and sperm sex sorting for the improvement of different aspects of swine production, artificial insemination with fresh or stored semen is currently the only sperm technology used at a commercial scale in the pig industry. The lower reproductive performance associated with the use of these sperm technologies is the reason for such limited use. Since optimal characteristics are required for successful application of frozen-thawed and sex-sorted boar spermatozoa, the present paper summarises the value of the current available methods for their functional assessment as well as the effects of these technologies on boar sperm functionality. In addition, strategies developed to reduce sperm damage and improve the yields of both sperm technologies in swine production are also reviewed with particular attention to the contributions of the authors.
{"title":"Optimal characteristics of spermatozoa for semen technologies in pigs.","authors":"I. Parrilla, J. M. Vázquez, I. Caballero, M. Gil, M. Hernandez, J. Roca, X. Lucas, E. Martinez","doi":"10.1530/biosciprocs.18.0003","DOIUrl":"https://doi.org/10.1530/biosciprocs.18.0003","url":null,"abstract":"Despite the great potential of sperm technologies such as sperm cryopreservation and sperm sex sorting for the improvement of different aspects of swine production, artificial insemination with fresh or stored semen is currently the only sperm technology used at a commercial scale in the pig industry. The lower reproductive performance associated with the use of these sperm technologies is the reason for such limited use. Since optimal characteristics are required for successful application of frozen-thawed and sex-sorted boar spermatozoa, the present paper summarises the value of the current available methods for their functional assessment as well as the effects of these technologies on boar sperm functionality. In addition, strategies developed to reduce sperm damage and improve the yields of both sperm technologies in swine production are also reviewed with particular attention to the contributions of the authors.","PeriodicalId":87420,"journal":{"name":"Society of Reproduction and Fertility supplement","volume":"66 1","pages":"37-50"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44847916","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}
Pub Date : 2020-10-12DOI: 10.1530/biosciprocs.18.0012
S. C. Hernandez, H. Finlayson, C. Ashworth, C. Haley, A. Archibald
Reproductive performance is a critical component of sustainable animal production systems. The low heritability of reproductive performance traits such as litter size, ovulation rate, and prenatal survival and their expression only in females limits improvement of these traits through traditional selective breeding programs. However, there is abundant evidence of genetic variation in these traits between pig breeds, which could be exploited to improve reproductive performance through selective breeding. The Chinese Meishan breed is one of the most prolific pig breeds known, displaying greater litter size than commercial Western breeds, such as Large White, through higher levels of prenatal survival for a given ovulation rate. But Meishan pigs have poor growth rates and high carcass fat content. However, increasing the number of viable and productive offspring per reproductive female reduces financial and environmental costs and improves the sustainability of the system. Thus, the superior Meishan alleles for reproduction traits are potentially commercially valuable. As only a fraction of the genes / loci that underpin the Meishan's superior reproductive performance have been identified to date, it is evident that the genetics of reproductive performance merits further investigation. In an earlier study we mapped a QTL (quantitative trait loci) with effects on embryo survival and litter size to the distal end of pig chromosome 8 (King et al. 2003). The objective of this study is to identify QTL affecting ovulation rate, teat number, litter size, number born alive and embryo survival, and characterize candidate gene(s) underlying such QTL. Our strategy to identify genetic markers for reproduction traits combines identifying QTL (regions of the genome linked to the phenotypes) through genome scans using interval mapping and testing genes recognized as candidates on both positional and physiological grounds. The QTL analyses involve testing for associations between variation in the trait(s) of interest and the inheritance of chromosomal segments from the parental animals. The inheritance of chromosomal segments through the QTL mapping population is tracked by genotyping the population for polymorphic genetic markers — microsatellites and single nucleotide polymorphisms (SNP5). The three-generation Roslin Institute Meishan x Large White F2 QTL mapping population was genotyped for ten additional markers across the QTL found previously on chromosome 8 and for 127 markers evenly spaced across the rest of the genome. The marker genotypes and trait data were lodged in the resSpecies database (www.resSpecies.org). Linkage maps were constructed using Multimap and Crimap (Green et al. 1990) and the resulting maps checked for anomalous double recombinants with the chrompic function. Anomalous genotypes were checked and corrected or omitted from the analysis. The marker orders in the linkage map exhibited good agreement with international reference linkage maps
{"title":"Mapping quantitative trait loci for reproduction in pigs.","authors":"S. C. Hernandez, H. Finlayson, C. Ashworth, C. Haley, A. Archibald","doi":"10.1530/biosciprocs.18.0012","DOIUrl":"https://doi.org/10.1530/biosciprocs.18.0012","url":null,"abstract":"Reproductive performance is a critical component of sustainable animal production systems. The low heritability of reproductive performance traits such as litter size, ovulation rate, and prenatal survival and their expression only in females limits improvement of these traits through traditional selective breeding programs. However, there is abundant evidence of genetic variation in these traits between pig breeds, which could be exploited to improve reproductive performance through selective breeding. The Chinese Meishan breed is one of the most prolific pig breeds known, displaying greater litter size than commercial Western breeds, such as Large White, through higher levels of prenatal survival for a given ovulation rate. But Meishan pigs have poor growth rates and high carcass fat content. However, increasing the number of viable and productive offspring per reproductive female reduces financial and environmental costs and improves the sustainability of the system. Thus, the superior Meishan alleles for reproduction traits are potentially commercially valuable. As only a fraction of the genes / loci that underpin the Meishan's superior reproductive performance have been identified to date, it is evident that the genetics of reproductive performance merits further investigation. In an earlier study we mapped a QTL (quantitative trait loci) with effects on embryo survival and litter size to the distal end of pig chromosome 8 (King et al. 2003). The objective of this study is to identify QTL affecting ovulation rate, teat number, litter size, number born alive and embryo survival, and characterize candidate gene(s) underlying such QTL. Our strategy to identify genetic markers for reproduction traits combines identifying QTL (regions of the genome linked to the phenotypes) through genome scans using interval mapping and testing genes recognized as candidates on both positional and physiological grounds. The QTL analyses involve testing for associations between variation in the trait(s) of interest and the inheritance of chromosomal segments from the parental animals. The inheritance of chromosomal segments through the QTL mapping population is tracked by genotyping the population for polymorphic genetic markers — microsatellites and single nucleotide polymorphisms (SNP5). The three-generation Roslin Institute Meishan x Large White F2 QTL mapping population was genotyped for ten additional markers across the QTL found previously on chromosome 8 and for 127 markers evenly spaced across the rest of the genome. The marker genotypes and trait data were lodged in the resSpecies database (www.resSpecies.org). Linkage maps were constructed using Multimap and Crimap (Green et al. 1990) and the resulting maps checked for anomalous double recombinants with the chrompic function. Anomalous genotypes were checked and corrected or omitted from the analysis. The marker orders in the linkage map exhibited good agreement with international reference linkage maps","PeriodicalId":87420,"journal":{"name":"Society of Reproduction and Fertility supplement","volume":"66 1","pages":"117-8"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45127112","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}
Pub Date : 2020-10-12DOI: 10.1530/biosciprocs.18.0030
Bischoff, S. Tsai, N. Hardison, A. Motsinger-Reif, B. Freking, J. Piedrahita
This chapter describes the application of functional genomic approaches to the study of imprinted genes in swine. While there are varied definitions of "functional genomics", in general they focus on the application of DNA microarrays, single nucleotide polymorphism (SNP) arrays, and other high coverage genomic analyses, and their combination with downstream methods of gene modification such as silencing RNA (siRNA) and viral and non-viral transfection. Between the initial data acquisition and the actual genetic manipulation of the system lies bioinformatics, where massive amounts of data are analyzed to extract meaningful information. This area is in constant flux with an increased emphasis on detection of affected pathways and processes rather than generation of simple affected gene lists. We will expand on each of these points and describe how we have used these technologies for the study of imprinted genes in swine. First we will introduce the biological question to provide context for the discussion of the functional genomic approaches and the types of information they generate.
{"title":"Functional genomic approaches for the study of fetal/placental development in swine with special emphasis on imprinted genes.","authors":"Bischoff, S. Tsai, N. Hardison, A. Motsinger-Reif, B. Freking, J. Piedrahita","doi":"10.1530/biosciprocs.18.0030","DOIUrl":"https://doi.org/10.1530/biosciprocs.18.0030","url":null,"abstract":"This chapter describes the application of functional genomic approaches to the study of imprinted genes in swine. While there are varied definitions of \"functional genomics\", in general they focus on the application of DNA microarrays, single nucleotide polymorphism (SNP) arrays, and other high coverage genomic analyses, and their combination with downstream methods of gene modification such as silencing RNA (siRNA) and viral and non-viral transfection. Between the initial data acquisition and the actual genetic manipulation of the system lies bioinformatics, where massive amounts of data are analyzed to extract meaningful information. This area is in constant flux with an increased emphasis on detection of affected pathways and processes rather than generation of simple affected gene lists. We will expand on each of these points and describe how we have used these technologies for the study of imprinted genes in swine. First we will introduce the biological question to provide context for the discussion of the functional genomic approaches and the types of information they generate.","PeriodicalId":87420,"journal":{"name":"Society of Reproduction and Fertility supplement","volume":"66 1","pages":"245-64"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43440594","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}
Pub Date : 2020-10-12DOI: 10.1530/biosciprocs.18.0034
J. Patterson, A. Cameron, T. Smith, A. Kummer, R. Schott, L. Greiner, J. Connor, G. Foxcroft
The principal goal of commercial breeding herds is to consistently meet weekly breeding targets. Weaned sows failing to return to estrus within 7 d after weaning contribute to missed breeding targets and increased non-productive sow days. Treatment with low doses of exogenous gonadotrophins (GT) has traditionally been used to advance and synchronize estrus in weaned primiparous sows. However, in well managed contemporary commercial sow farms, more than 90% of sows may return to estrus within 7 d after weaning, posing questions about the likely efficacy of exogenous GT treatment. Therefore, the primary objective of the present study was to determine the response to GT treatment at weaning in contemporary parity 1 commercial sows with lactation lengths typical of the North American swine industry. Primiparous crossbred sows (PIC C22, n = 275; and PIC C29, n — 131) from a 5,000 sow commercial farrow-to-wean facility (Wildcat, Carthage Veterinary Service, Carthage, IL) were blocked by estimated farrowing weight and genetic line and then randomly allocated to either receive a combination dose of 400 IU eCG and 200 IU hCG (PG600, Intervet, USA, De Soto, KS) I.M. in the neck on the morning of weaning (PG group; n = 189), or to be untreated controls (CON group; n = 218). From the day after weaning, all sows were provided twice daily fence-line contact with mature boars for stimulation and detection of estrus. Sows were bred according to established herd protocols with doses of 3.0 x 109sperm cells/insemination. Reproductive parameters analyzed were estrus synchronization rate (ESR),determined as the number of sows with observed standing heat within 7 d after weaning, weaning-to-estrus interval (WEI), proportion of sows bred over a 3-d period (BRD3), proportion of sows bred that farrowed (FR), total litter size (TB), and total live born piglets (BA) at farrowing. Based on WEI, sows were retrospectively grouped into 4 categories (WCAT); 1) Target Breed Week: sows bred within 7 d post-weaning, 2) "Tail-enders" sows with an extended 8-19 d WEI , 3) "Missed heats" sows detected in heat a 20 d post weaning, or 4) No detected heat by 30 d post weaning. Estimatedfarrowing (193.6 ± 1.5 vs 192.2 ± 1.6 kg)and weaning (189.4 ± 1.3 vs 188.0 ± 1.4 kg) weights were similar in CON and PG sows, respectively, and marginal weight loss in lactation was recorded across all sows (4.2 kg). Considering data from all sows assigned to treatment (Table 1), treatment did not affect the proportion of sows bred within 7 d after weaning (ESR),or within a 3-d breeding window (BRD3). However, the timing of this 3-d breeding window (d 4, 5 and 6 for CON vs d 3, 4 and 5 for PG sows) reflected a shorter (P < 0.001) WEI in PG compared to CON sows. PG treatment also eliminated the incidence of sows with an extended WEI (classified as "tail enders"), and reduced variance (P <0.05) in WEI in PG (0.07) compared to CON (0.14) sows when considered over the 19-d period after weaning. For those sow
商业种猪群的主要目标是持续满足每周的繁殖目标。断奶母猪未能在断奶后7天内恢复发情，导致错过繁殖目标，增加非生产母猪天数。传统上，低剂量外源性促性腺激素(GT)用于促进和同步断奶初产母猪的发情。然而，在管理良好的现代商业母猪养殖场，超过90%的母猪可以在断奶后7天内恢复发情，这对外源性GT治疗的可能效果提出了疑问。因此，本研究的主要目的是确定当代1胎商品母猪断奶时对GT治疗的反应，这些母猪具有典型的北美养猪业的泌乳期。初产杂交母猪(PIC C22, n = 275;和PIC C29, n - 131)，来自5000头母猪的商业化产仔断奶设施(Wildcat, Carthage Veterinary Service, Carthage, IL)，通过估计的产仔体重和遗传系进行阻断，然后随机分配，在断奶早上在颈部接受400 IU eCG和200 IU hCG (PG600, Intervet, USA, De Soto, KS) I.M. (PG组;n = 189)或未治疗对照组(CON组;N = 218)。从断奶后第一天起，所有母猪每天两次与成熟公猪围栏接触，以刺激和检测发情。母猪按照既定的群体方案繁殖，每次授精剂量为3.0 × 109个精子细胞。分析的繁殖参数包括发情同步率(ESR)，即断奶后7 d内观察到站热的母猪数量、断奶至发情间隔(WEI)、3-d周期内饲养的母猪比例(BRD3)、已分娩母猪比例(FR)、总产仔数(TB)和分娩时活产仔猪总数(BA)。基于WEI，将母猪回顾性分为4类(WCAT);1)目标品种周:断奶后7天内的母猪;“尾尾型”母猪寿命延长至8-19天，3)“缺热”母猪在断奶后20天出现发热量，或4)在断奶后30天没有发现发热量。CON和PG母猪的估计产仔体重(193.6±1.5 vs 192.2±1.6 kg)和断奶体重(189.4±1.3 vs 188.0±1.4 kg)相似，所有母猪的泌乳体重均出现边际下降(4.2 kg)。考虑到所有分配到治疗组的母猪的数据(表1)，治疗并没有影响断奶后7天内(ESR)或3-d繁殖窗口(BRD3)内繁殖的母猪比例。然而，这个3-d繁殖窗口的时间(CON母猪的第4、5和6天，而PG母猪的第3、4和5天)反映出PG母猪的WEI比CON母猪短(P < 0.001)。在断奶后19 d期间，PG处理还消除了母猪WEI延长(归类为“尾端”)的发生率，并且与CON(0.14)母猪相比，PG(0.07)降低了WEI的方差(P <0.05)。断奶后7 d内母猪产仔率(82.8 vs 86.4%)、总产仔数(12.2±0.3 vs 12.9±0.3)和产活仔数(11.6±0.3 vs 12.1±0.3)
{"title":"Responses to exogenous gonadotrophin treatment in contemporary weaned sows.","authors":"J. Patterson, A. Cameron, T. Smith, A. Kummer, R. Schott, L. Greiner, J. Connor, G. Foxcroft","doi":"10.1530/biosciprocs.18.0034","DOIUrl":"https://doi.org/10.1530/biosciprocs.18.0034","url":null,"abstract":"The principal goal of commercial breeding herds is to consistently meet weekly breeding targets. Weaned sows failing to return to estrus within 7 d after weaning contribute to missed breeding targets and increased non-productive sow days. Treatment with low doses of exogenous gonadotrophins (GT) has traditionally been used to advance and synchronize estrus in weaned primiparous sows. However, in well managed contemporary commercial sow farms, more than 90% of sows may return to estrus within 7 d after weaning, posing questions about the likely efficacy of exogenous GT treatment. Therefore, the primary objective of the present study was to determine the response to GT treatment at weaning in contemporary parity 1 commercial sows with lactation lengths typical of the North American swine industry. Primiparous crossbred sows (PIC C22, n = 275; and PIC C29, n — 131) from a 5,000 sow commercial farrow-to-wean facility (Wildcat, Carthage Veterinary Service, Carthage, IL) were blocked by estimated farrowing weight and genetic line and then randomly allocated to either receive a combination dose of 400 IU eCG and 200 IU hCG (PG600, Intervet, USA, De Soto, KS) I.M. in the neck on the morning of weaning (PG group; n = 189), or to be untreated controls (CON group; n = 218). From the day after weaning, all sows were provided twice daily fence-line contact with mature boars for stimulation and detection of estrus. Sows were bred according to established herd protocols with doses of 3.0 x 109sperm cells/insemination. Reproductive parameters analyzed were estrus synchronization rate (ESR),determined as the number of sows with observed standing heat within 7 d after weaning, weaning-to-estrus interval (WEI), proportion of sows bred over a 3-d period (BRD3), proportion of sows bred that farrowed (FR), total litter size (TB), and total live born piglets (BA) at farrowing. Based on WEI, sows were retrospectively grouped into 4 categories (WCAT); 1) Target Breed Week: sows bred within 7 d post-weaning, 2) \"Tail-enders\" sows with an extended 8-19 d WEI , 3) \"Missed heats\" sows detected in heat a 20 d post weaning, or 4) No detected heat by 30 d post weaning. Estimatedfarrowing (193.6 ± 1.5 vs 192.2 ± 1.6 kg)and weaning (189.4 ± 1.3 vs 188.0 ± 1.4 kg) weights were similar in CON and PG sows, respectively, and marginal weight loss in lactation was recorded across all sows (4.2 kg). Considering data from all sows assigned to treatment (Table 1), treatment did not affect the proportion of sows bred within 7 d after weaning (ESR),or within a 3-d breeding window (BRD3). However, the timing of this 3-d breeding window (d 4, 5 and 6 for CON vs d 3, 4 and 5 for PG sows) reflected a shorter (P < 0.001) WEI in PG compared to CON sows. PG treatment also eliminated the incidence of sows with an extended WEI (classified as \"tail enders\"), and reduced variance (P <0.05) in WEI in PG (0.07) compared to CON (0.14) sows when considered over the 19-d period after weaning. For those sow","PeriodicalId":87420,"journal":{"name":"Society of Reproduction and Fertility supplement","volume":"66 1","pages":"303-4"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45330111","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}
Pub Date : 2020-10-12DOI: 10.1530/biosciprocs.18.0001
Heriberto Rodríguez-Martínez, Ulrik Kvist, F. Saravia, M. Wallgren, A. Johannisson, L. Sanz, Fernando J. Peña, E. Martinez, J. Roca, J. M. Vázquez, J. J. Calvete
During ejaculation in the boar, sperm cohorts emitted in epididymal cauda fluid are sequentially exposed and resuspended in different mixtures of accessory sex gland secretion. This paper reviews the relevance of such unevenly composed fractions of seminal plasma (SP) in vivo on sperm transport and sperm function and how this knowledge could benefit boar semen processing for artificial insemination (AI). The firstly ejaculated spermatozoa (first 10 ml of the sperm-rich fraction, SRF [P1]) remain mainly exposed to epididymal cauda fluid and its specific proteins i.e. various lipocalins, including the fertility-related prostaglandin D synthase; than to prostatic and initial vesicular gland secretions. P1-spermatozoa are hence exposed to less bicarbonate, zinc or fructose and mainly to PSP-I spermadhesin; than if they were in the rest of the SRF and the post-SRF (P2). Since the P1-SP is less destabilizing for sperm membrane and chromatin, P1-spermatozoa sustain most in vitro procedures, including cryopreservation, the best. Moreover, ejaculated firstly, the P1-spermatozoa seem also those deposited by the boar as a vanguard cohort, thus becoming overrepresented in the oviductal sperm reservoir (SR). This vanguard SR-entry occurs before the endometrial signalling of SP components (as PSP-I/PSP-II and cytokines) causes a massive influx of the innate defensive PMNs to cleanse the uterus from eventual pathogens, superfluous spermatozoa and the allogeneic SP. The SP also conditions the mucosal immunity of the female genital tract, to tolerate the SR-spermatozoa and the semi-allogeneic conceptus. These in vivo gathered data can be extrapolated into procedures for handling boar spermatozoa in vitro for AI and other biotechnologies, including simplified cryopreservation.
{"title":"The physiological roles of the boar ejaculate.","authors":"Heriberto Rodríguez-Martínez, Ulrik Kvist, F. Saravia, M. Wallgren, A. Johannisson, L. Sanz, Fernando J. Peña, E. Martinez, J. Roca, J. M. Vázquez, J. J. Calvete","doi":"10.1530/biosciprocs.18.0001","DOIUrl":"https://doi.org/10.1530/biosciprocs.18.0001","url":null,"abstract":"During ejaculation in the boar, sperm cohorts emitted in epididymal cauda fluid are sequentially exposed and resuspended in different mixtures of accessory sex gland secretion. This paper reviews the relevance of such unevenly composed fractions of seminal plasma (SP) in vivo on sperm transport and sperm function and how this knowledge could benefit boar semen processing for artificial insemination (AI). The firstly ejaculated spermatozoa (first 10 ml of the sperm-rich fraction, SRF [P1]) remain mainly exposed to epididymal cauda fluid and its specific proteins i.e. various lipocalins, including the fertility-related prostaglandin D synthase; than to prostatic and initial vesicular gland secretions. P1-spermatozoa are hence exposed to less bicarbonate, zinc or fructose and mainly to PSP-I spermadhesin; than if they were in the rest of the SRF and the post-SRF (P2). Since the P1-SP is less destabilizing for sperm membrane and chromatin, P1-spermatozoa sustain most in vitro procedures, including cryopreservation, the best. Moreover, ejaculated firstly, the P1-spermatozoa seem also those deposited by the boar as a vanguard cohort, thus becoming overrepresented in the oviductal sperm reservoir (SR). This vanguard SR-entry occurs before the endometrial signalling of SP components (as PSP-I/PSP-II and cytokines) causes a massive influx of the innate defensive PMNs to cleanse the uterus from eventual pathogens, superfluous spermatozoa and the allogeneic SP. The SP also conditions the mucosal immunity of the female genital tract, to tolerate the SR-spermatozoa and the semi-allogeneic conceptus. These in vivo gathered data can be extrapolated into procedures for handling boar spermatozoa in vitro for AI and other biotechnologies, including simplified cryopreservation.","PeriodicalId":87420,"journal":{"name":"Society of Reproduction and Fertility supplement","volume":"66 1","pages":"1-21"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45980525","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}
Pub Date : 2020-10-12DOI: 10.1530/biosciprocs.18.0017
R. Prather, J. Ross, Isom S Clay, Jonathan A Green
Embryogenesis is a complex process that is controlled at various levels. As new discoveries are made about molecular mechanisms that control development in other species, it is apparent that these same mechanisms regulate pig embryogenesis as well. Methylation of DNA and modification of histones regulate transcription, and mechanisms such as ubiquitinization, autophagy and microRNAs regulate development post-transcriptionally. Each of these systems of regulation is highly dynamic in the early embryo. A better understanding of each of these levels of regulation can provide tools to potentially improve the reproductive process in pigs, to improve methods of creating pig embryos and cloned embryos in vitro, and to provide markers for predicting developmental competence of the embryo.
{"title":"Transcriptional, post-transcriptional and epigenetic control of porcine oocyte maturation and embryogenesis.","authors":"R. Prather, J. Ross, Isom S Clay, Jonathan A Green","doi":"10.1530/biosciprocs.18.0017","DOIUrl":"https://doi.org/10.1530/biosciprocs.18.0017","url":null,"abstract":"Embryogenesis is a complex process that is controlled at various levels. As new discoveries are made about molecular mechanisms that control development in other species, it is apparent that these same mechanisms regulate pig embryogenesis as well. Methylation of DNA and modification of histones regulate transcription, and mechanisms such as ubiquitinization, autophagy and microRNAs regulate development post-transcriptionally. Each of these systems of regulation is highly dynamic in the early embryo. A better understanding of each of these levels of regulation can provide tools to potentially improve the reproductive process in pigs, to improve methods of creating pig embryos and cloned embryos in vitro, and to provide markers for predicting developmental competence of the embryo.","PeriodicalId":87420,"journal":{"name":"Society of Reproduction and Fertility supplement","volume":"66 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":"44219129","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}
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