猪骨形态发生蛋白-6基因多态性及其与产仔性能的关联性分析

试验旨在研究猪骨形态发生蛋白-6（bone morphogenetic protein 6, BMP-6）基因多态性及其与产仔性能的关联。采用PCR-SSCP技术检测了野猪、民猪、长白猪、北京黑猪、法系大白猪5个猪种268个个体BMP-6基因的多态性,并分析了BMP-6基因多态性与法系大白猪产仔性能的关联性。结果表明,猪BMP-6基因CDS区1104位存在1个G→A的同义突变,产生AA、AB、BB 3种基因型,其中在野猪和民猪中,A等位基因频率高;在长白猪、北京黑猪和法系大白猪中,B等位基因频率高。不同基因型对法系大白猪产仔数和产活仔数的影响差异显著（P<0.05）,初步认为BMP-6基因多态性与产仔性能显著关联。     

猪骨形态发生蛋白-6基因多态性及其与产仔性能的关联性分析

试验旨在研究猪骨形态发生蛋白-6（bone morphogenetic protein 6, BMP-6）基因多态性及其与产仔性能的关联。采用PCR-SSCP技术检测了野猪、民猪、长白猪、北京黑猪、法系大白猪5个猪种268个个体BMP-6基因的多态性,并分析了BMP-6基因多态性与法系大白猪产仔性能的关联性。结果表明,猪BMP-6基因CDS区1104位存在1个G→A的同义突变,产生AA、AB、BB 3种基因型,其中在野猪和民猪中,A等位基因频率高;在长白猪、北京黑猪和法系大白猪中,B等位基因频率高。不同基因型对法系大白猪产仔数和产活仔数的影响差异显著（P<0.05）,初步认为BMP-6基因多态性与产仔性能显著关联。     

猪催乳素受体基因第8内含子多态性及其对产仔性能的影响

采用PCR-SSCP技术检测了大白猪、长白猪、杜洛克猪、马身猪、山西黑猪和山西白猪等6个品种364头个体催乳素受体基因(prolactin,PRLR)第8内含子的多态性,并分析了多态位点对猪头胎产仔性能的影响。结果表明,猪PRLR基因第8内含子存在多态性,共检测到A、B、C 3个等位基因和AA、AB、AC、BB、BC和CC 6种基因型。在杜洛克猪、长白猪、山西黑猪和山西白猪群体中,A等位基因的频率最高,分别为0.8276、0.5439、0.5345和0.7669;而在大白猪和马身猪群体中,B等位基因的频率最高,分别为0.6894和0.7000;仅在大白猪、山西黑猪和山西白猪中检测到C等位基因,且频率较低,在0.0379~0.1385之间。PRLR基因型对母猪头胎产仔数有显著影响(P<0.05),对产活仔数的影响未达显著水平。AC基因型母猪的头胎产仔数和产活仔数显著高于BC基因型个体,而与AA、AB和BB基因型个体差异不显著。含有A等位基因的母猪的产仔性能优于不带有A等位基因的个体,表明A等位基因是有利于母猪产仔性能提高的等位基因,可应用于标记辅助选择来提高母猪的繁殖性能。     

Effects of prolactin receptor genotype on the litter size of Mangalica

The aim of this study was to detect different alleles of the prolactin receptor (PRLR) gene and to examine their effects on the litter size of the indigenous Hungarian pig, the Mangalica. G1789A single nucleotide polymorphism (SNP) was investigated as a candidate for litter size. Samples from 80 purebred Mangalica sows and data of their 335 litters were provided by Olmos & Tóth Ltd. Hair follicles were used to isolate the required DNA. Allelic discrimination was performed by means of the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method using the AluI restriction enzyme and agarose gel electrophoresis. In the population examined, the A allele was found to be preferable in the Mangalica breed group. The most advantageous AA genotype was the least prevalent (8.75%), while the frequencies of AB and BB were 40% and 51.25%, respectively. Remarkably, the average number of piglets born alive per litter was 1.11 ± 0.39 higher in sows with AA as compared to those with BB genotype. By raising the frequency of the AA genotype, the litter size is likely to increase. However, the effect of PRLR genotypes can differ among pig breeds and even lines. Further studies may be required to observe and estimate possible pleiotropic effects of this polymorphism on other traits.     

胎次对杜洛克、长白和大白母猪繁殖性能的影响

为了研究胎次对杜洛克、长白和大白母猪繁殖性能的影响,根据江苏省某国家级生猪核心育种场2009-2011年出生的繁殖母猪资料,分别选取128头杜洛克、681头长白和610头大白母猪共7280窝生产数据,统计分析不同胎次母猪的总产仔数、产活仔数、断奶仔猪数、初生窝重及校正21日龄窝重。此外,依据胎次将母猪分为3个繁殖阶段（1～2胎、3～6胎及7～8胎）来探究品种差异对母猪繁殖性能的影响。结果表明：胎次对母猪繁殖性能有显著影响（P<0.05）,母猪1～4胎的总产仔数、产活仔数、断奶仔猪数及初生窝重随胎次呈增加趋势,第4胎达到高峰,且显著高于其他胎次（P<0.05）;3～6胎繁殖性能较好,7胎之后出现迅速下降趋势;除在第4胎略有下降外,其他胎次的校正21日龄窝重随胎次递增。品种对母猪繁殖性能的影响显著（P<0.05）,长白和大白母猪的繁殖性能均极显著高于杜洛克母猪（P<0.01）;长白母猪的产活仔数和校正21日龄窝重显著高于大白母猪（P<0.05）,2个品种其他繁殖性能无显著差异（P＞0.05）。综上所述,杜洛克、长白和大白母猪的最佳繁殖胎次为3～6胎,长白猪的繁殖性能总体上优于大白猪,就本试验所在的育种场而言,长白猪可能更适合作为二元母猪生产中的母本。     

松辽黑猪METTL23基因多态性及其与繁殖性状的关联分析

为探究松辽黑猪METTL23基因多态性及其与繁殖性状的关联性,试验选取178头松辽黑猪母猪为研究对象,利用Sanger直接测序法查找METTL23基因外显子1~5的单核苷酸多态性(SNP),使用SPSS 19.0软件分析METTL23基因SNP位点与松辽黑猪繁殖性状(总产仔数、产活仔数、断奶仔猪数、初生重、3周龄重、断奶重、乳头数)的关联性。结果显示,仅在松辽黑猪METTL23基因外显子4发现1个SNP位点,命名为A62G,在A62G位点上检测到3种基因型,分别是AA、AG和GG。GG和G分别为优势基因型和优势等位基因,且A62G位点处于Hardy-Weinberg平衡状态(P>0.05)。该位点的遗传纯合度(Ho)为0.6516,高于遗传杂合度(He,0.3484),说明其在松辽黑猪群体中的变异较小;多态信息含量(PIC)为0.2877,属于中度多态位点(0.25<PIC<0.5),说明该遗传标记能够提供一定量的遗传信息。关联分析结果表明,GG基因型个体总产仔数、产活仔数和断奶仔猪数均显著或极显著高于AA基因型个体(P<0.05;P<0.01),总产仔数还显著高于AG基因型个体(P<0.05);AG基因型个体断奶仔猪数显著高于AA基因型个体(P<0.05);初生重、3周龄重、断奶重、乳头数各基因型间差异均不显著(P>0.05)。综上所述,METTL23基因外显子4存在多态性位点A62G,该位点与松辽黑猪产仔数存在显著关联,可作为松辽黑猪产仔数的遗传标记,用于分子育种。     

Detection of novel single-nucleotide polymorphisms (SNPs) in the CYP21 gene and association analysis of two SNPs for CYP21 and ESR2 with litter size in a commercial sow population

Altogether 129 F₁ sows from a commercial sow farm with at least four litters were genotyped for the oestrogen receptor 2 gene (ESR2) and cytochrome P450 hydroxylase 21 gene (CYP21) and investigated for associations on the litter‐size parameters: total number born and number born alive. Five novel polymorphisms were found in the 3′‐untranslated region for the CYP21 gene. Genotype and allele frequencies for the CYP21 (position 3462G > A) single‐nucleotide polymorphism (SNP) were 0.434 (GG), 0.504 (AG), 0.062 (AA) and 0.69 (G):0.31 (A), respectively. No association was found between this polymorphism and litter‐size parameters. For the ESR2 gene, the SNP in exon 5 associated with an amino acid substitution MET (allele A) > VAL (allele G) was investigated. Only two genotypes were found leading to allele frequencies of 0.34 (A):0.66 (G). Only number born alive piglets were significantly increased for the AG genotype (p = 0.034) with 11.64 piglets per sow and litter in comparison with the GG genotype, leading to only 10.96 piglets per sow and litter. From these data, it can be concluded that the investigated SNP of the ESR2 gene is associated with the number of liveborn piglets in the commercial population considered, and hence could be useful in selection for litter size. Therefore, this gene should be investigated in additional populations.     

Sow efficiency and early piglet mortality in two local pig breeds on smallholder farms in northern Vietnam—a longitudinal study

In the recent past, pig performance and sow management on smallholder farms in the Southeast Asian Massif have been extensively researched. But the objective of this study was to investigate the lifetime efficiency of breeding sows of the local Vietnamese Ban (n = 89) and Mong Cai (n = 131) breeds in a production system context. The impact of sow longevity was considered in particular. In addition, predictors of early pre-weaning mortality in piglets were investigated. In total, nine villages of Son La province, situated in the uplands of north-western Vietnam, were selected, differing in access to markets, production intensity, and pig management level. Data was collected over a period of 10 years through an on-farm performance testing system. It was shown that sows of both breeds that achieved five or more parities farrowed and weaned significantly more piglets per life year compared to sows with only one or two parities. The conception rate (Spearman’s rho = 0.374) and age at first farrowing (Spearman’s rho = ?0.424) were significantly correlated with the number of weaned piglets per life year of stayable (≥4 parities) Mong Cai sows. The risk of early pre-weaning death of piglets born to Mong Cai sows was affected more by litter size, while for piglets born to Ban sows, the risk was influenced more by the season. Therefore, interventions to improve the sow lifetime efficiency and piglet survivability must match the sow breed and management level.     

Hormonal therapy for sows weaned during fall and winter

Sows from five commercial herds were weaned in the fall and winter and used to ascertain the potential application of hormonal therapy to stimulate subsequent litter size born. At weaning sows within parity (1, 2, and 3 through 6) and lactation length classification (early weaned, < or = 14 d; conventionally weaned, > 14 d) were randomly assigned to treatment. Treatments were injection with P.G. 600 (400 IU PMSG with 200 IU hCG) at weaning or no treatment. Sows were individually observed for estrus and mated following protocol for each herd. Breeding, culling, and farrowing data were collected. Treatment with P.G. 600 did not change subsequent rebreeding performance for sows at parity 1 or parities 3 through 6. However, conventionally weaned parity-2 sows treated with P.G. 600 were more likely (P < .05) to return to estrus than conventionally weaned controls (99.0 vs 93.6%, respectively). For parity-1 and parity-2 sows, treatment did not significantly change the likelihood for farrow percentage. However, the likelihood to farrow a litter was greater (P < .05) among P.G. 600-treated sows at parities 3 to 6 that were conventionally weaned (84.4 vs 71.3%, respectively). Subsequent litter birth weight for parity-1 sows treated with P.G. 600 was lower (P < .02) than for controls (15.6 vs 16.6 kg, respectively). Subsequent litter size at birth was not affected by treatment for parity-1 or parity-2 sows compared with controls. However, early-weaned sows at parities 3 through 6 treated with P.G. 600 had more (P < .06) total number born than controls (12.4 vs 10.6, respectively). Treatment with P.G. 600 improved reproductive function within specific parity and lactation length classification for sows weaned in the fall and winter.     

Urogenital diseases and their effect on reproductive performance in high-parity sows

In a Slowakian indoor pig production unit (2423 sows), from June to December 2002 all culled sows with excessive vulval discharge at culling, and with vulval discharge and periparturient disease in their previous history were subjected to retrospective lifetime production analysis. The sows were assigned to nine groups according to parity (parity 1-9). Average total litter size, average live-born litter size, average stillbirth rate, average mummy rate, and average litter weaning weight were evaluated retrospectively for all births. Non-culled sows represented the control animals. The percentage of animals with periparturient disease and vulval discharge in their history differed between parities. Parity 2, 3, and 4 sows had a significantly lower percentage of vulval discharge and periparturient disease in their history than sows of other parities. Compared to parity 1-6 sows, parity 7-9 sows had significantly lower (P < .001) conception rates, farrowing rates, and adjusted farrowing rates. Compared to parity 1-2 and 7-9 sows, parity 3-6 sows had a significantly larger (P < .001) lifetime average total born and live-born litter size. Compared to parity 1-3 and 7-9 sows, parity 4-6 sows had a significantly lower (P < .001) rate of stillbirths over all parities. No differences in mummy rates were detected between the sows of different parities. Compared to parity 1-2 and 7-9 sows, parity 3-6 sows had significantly higher (P < .001) weaning litter weights over all parities. Sows without a history of vulval discharge and periparturient disease had higher (P < .001) production levels in parity 7-9. IMPLICATIONS: The present results indicate that parity markedly influences the production level of sows that have a history of periparturient disease and vulval discharge.     

Development of allele-specific primer PCR for a swine TLR2 SNP and comparison of the frequency among several pig breeds of Japan and the Czech Republic

In the present study, we have developed an allele-specific primer-polymerase chain reaction (ASP-PCR) for genotyping a single nucleotide polymorphism (SNP) of swine Toll-like receptor 2 (TLR2) (C406G), which is related to the prevalence of pneumonia caused by Mycoplasma hyopneumoniae. We also compared the allele frequency among several pig breeds of Japan and the Czech Republic. Allele-specific primers were constructed by introducing 1-base mismatch sequence before the SNP site. The swine TLR2 C406G mutation was successfully determined by the ASP-PCR using genomic DNA samples in Japan as previously genotyped by a sequencing method. Using the PCR condition determined, genomic DNA samples from pig blood obtained from 110 pigs from 7 different breeds in the Czech Republic were genotyped by the ASP-PCR. The genotyping results from the ASP-PCR were completely matched with the results from the sequencing method. The allele frequency of the swine TLR2 C406G mutation was 27.5% in the Czech Republic and 3.6% in Japan. The C406G mutation was only found in the Landrace breed in Japan, and was almost exclusively found in the Landrace breed in the Czech Republic as well. These results indicated the usefulness of ASP-PCR for detecting a specific SNP for swine TLR2.     

FSHβ基因的多态性分布及其对大白猪产活仔数的影响

为了研究猪繁殖性状候选主效基因FSHβ在大白猪不同胎次中的遗传效应,并应用于大白猪繁殖性状的遗传改良,采用PCR方法检测了该基因在2个大白猪育种群共802头母猪中的多态性分布,并分析了其对产活仔数的影响,其中湖北天种公司大白猪群体样本数为472头,分析统计胎次1774胎,等位基因A的频率为0.447、等位基因B的频率为0.553;宜昌正大公司大白猪群为330头,分析统计胎次1644胎,等位基因A、B的频率分别为0.312、0.688。分析该位点的多态性与产活仔数的关系,结果发现,头胎不同基因型对产活仔数的影响为ABBBAA,二胎为AAABBB,经产胎次和所有胎次均为ABAABB,但差异均不显著。综合分析结果表明,A等位基因对大白猪产活仔数的影响要优于B等位基因,AB基因型母猪的产活仔数要优于其他2种基因型,提高生产猪群该基因的杂合子个体数比例有望取得更大的经济效益。     

猪FSHβ基因第2外显子多态性与产仔性能的关联分析

采用PCR-SSCP技术检测马身猪、杜洛克猪、大白猪、山西黑猪和山西白猪等5个猪种421个个体FSHβ基因编码区的多态性,采用单变量动物模型分析了多态位点对母猪产仔性能的影响。结果表明:在FSHβ基因第2外显子第48位上检测到C→T的转换突变为同义突变。在杜洛克群体中,C等位基因的频率为1;在马身猪群体中,T等位基因的频率为1;在山西白猪和山西黑猪中,等位基因C的频率相对较高,分别为0.65和0.89。不同基因型母猪总产仔数和产活仔数的差异不显著(P>0.05),可初步判断该突变位点对猪的产仔性能无显著影响。     

The T allele at the g.1471620G>T in the EDG1 gene associated with high marbling in Japanese Black cattle is at a low frequency in breeds not selected for marbling

Our previous study detected a single nucleotide polymorphism (SNP), g.1471620G > T , in the 5' flanking region of the endothelial differentiation sphingolipid G-protein-coupled receptor 1 ( EDG1 ) gene, which has been considered as a positional functional candidate for the gene responsible for marbling, and showed association of the g.1471620G > T SNP with marbling in Japanese Black beef cattle. In the present study, we investigated the allele frequency distribution of the g.1471620G > T SNP among the 5 cattle breeds, Japanese Black, Japanese Brown, Japanese Short Horn, Holstein, and Brown Swiss breeds. The T allele at the g.1471620G > T SNP associated with high marbling was found at high frequency in Japanese Black breed that has been subjected to a strong selection for high marbling, while the allele was absent or at very low frequencies in the other breeds that have not been strongly selected for high marbling. Based on this finding, we hypothesized that the pressure of the strong selection for high marbling in Japanese Black breed has increased the frequency of the T allele at the g.1471620G > T SNP in the EDG1 .     

Genetic parameters for litter traits at different parities in purebred Landrace and Yorkshire pigs

Comparison of the multi‐trait animal model and the traditional repeatability model was carried out using data obtained from 6,424 Landrace and 20,835 Yorkshire sows farrowed from January 2000 to April 2018 in order to estimate genetic parameters for litter traits at different parities. Specifically, records of the total number born (TNB), number born alive (NBA), total number of mortality (MORT), number of stillborn (NSB) and number of mummified pigs (MUM) were used. Although results showed the heterogeneity of heritability for litter traits at different parities, the mean heritability estimates from the multi‐trait model were found to be higher than those of the repeatability model for all traits in both pig breeds. In terms of genetic correlation between parities, a slight difference in genetic control in the first parity was noted for TNB and NBA in Landrace and Yorkshire pigs. The correlation between the first parity and later parities ranged from 0.48 to 0.74 for TNB and NBA in both breeds. Moreover, genetic correlation between parities for MORT and NSB was observed to be high for parities higher than 2 in Yorkshire pigs. For MUM, genetic correlation between the first and other parities was generally low in both breeds, indicating that culling pigs on the basis of MUM at the first parity could probably be unreasonable. Overall, the results of this study suggest that the multi‐trait approach for litter size traits is useful for the accurate estimation of genetic parameters.     

绵羊TSHR基因多态性及其与繁殖性状关联分析

为探讨TSHR基因多态性与绵羊季节性繁殖和产羔数的关系,本实验采用Sequenom Mass-ARRAY?SNP分型技术检测常年发情的小尾寒羊(407只)、湖羊(101只)、策勒黑羊(48只)和季节性发情的苏尼特羊(21只)、滩羊(22只)、草原型藏羊(161只)TSHR基因的单核苷酸多态性(SNP)位点,并进行群体遗传学分析及其与小尾寒羊产羔数的关联分析。结果表明:TSHR基因g.89430525G>A、g.89363881T>C和g.89431097C>G的基因型频率和等位基因频率在常年发情绵羊品种和季节性发情绵羊品种间差异极显著(P<0.01);这3个SNP位点在大多数绵羊品种中表现为中度多态,且在各个绵羊品种中处于哈代温伯格平衡状态(P>0.05);TSHR基因g.89431097C>G位点的多态性与小尾寒羊第1～3胎的产羔数显著相关(P<0.05),其中CC型母羊的产羔数显著低于CG和GG型母羊(P<0.05)。本研究表明,TSHR基因与绵羊季节性繁殖性状具有较强的相关性,同时参与绵羊季节性繁殖和多羔性状的调控。     

Exploring polymorphisms and their effects on reproductive traits of the INHA and INHβA genes in three goat breeds

In this study, we report the analysis of INHA and INHβA gene polymorphisms in 786 goats of three breeds: Xinong Saanen (SN), Guanzhong (GZ) and Boer (BG). We identified three new allelic variants: P1–C80G and/126G (GenBank accession no. HQ202573) in the three goat breeds and P2–C936T (GenBank accession no. HQ202572) in SN and GZ goat breeds. At P1 locus, AA, AB and BB genotypes were found in the three goat breeds. At P2 locus, CC and CT genotypes were found in SN and GZ goat breeds. After comparing genotype distribution within the three goat breeds, BG had conspicuous differences from SN and GZ (P < 0.001) at P2 locus. The SNP locus was in Hardy–Weinberg disequilibrium at P1 locus in the three goat breeds (P < 0.05). At P2 locus, the SNP locus was in Hardy–Weinberg disequilibrium in SN and GZ goat breeds (P < 0.05). Association of polymorphisms with litter size was done at P1 locus in the three goat breeds. The result showed that AA genotype had remarkable litter size at P1 locus in the three goat breeds (P < 0.05). Therefore, these results suggest that INHA gene is a strong candidate gene that affects litter size in goats.     

四川省外种猪ESR基因对繁殖及生长性状的影响

试验以四川省外种母猪的 3个品种 (大约克、长白、杜洛克 )为研究对象 ,采用PCR -RFLps的方法测其ESR基因的PvuⅡ多态性 ,分析了该产仔数及生长性状之间的关系。结果表明 :初产胎次中 ,ESR基因型间总产仔数 (TNB)和产活仔数 (NBA)差异极显著 (P <0 0 1 ) ,BB和AA纯合子间TNB和NBA分别相差 5 97和 3 72头 ,基因加性效应分别应为每个B基因 2 98和 1 86头。对于经产胎次 ,总产仔数在AA ,AB基因与BB基因型的差异达到极显著水平 (P <0 0 1 ) ,产活仔数在AA基因型与BB基因型间差异显著 (P <0 0 5 ) ,TNB和NBA母猪每窝BB纯合子比AA纯合子分别多 3 6 8和 2 89头 ,基因的加性效应为每个B基因分别为 1 83和 1 4 4头。头胎和经产胎次ESR基因型在初生窝重、2 0日龄头数和窝重、30或 4 5日龄头数和窝重以及 70日龄窝重之间的差异不显著 (P >0 0 5 ) ;但是以上 6个性状在ESR基因的 3种基因型间存在BB >AB >AA的趋势     

Genetic analysis for sow stayability at different parities in purebred Landrace and Large White pigs

Genetic parameters for sow stayability were estimated from farrowing records of 10,295 Landrace sows and 8192 Large White sows. The record for sow stayability from parity k to parity k + 1 (k = 1, …, 6) was 0 when a sow had a farrowing record at parity k but not at parity k + 1, and 1 when a sow had both records. Heritability was estimated by using single-trait linear and threshold animal models. Genetic correlations among parities were estimated by using two-trait linear–linear and single-trait random regression linear animal models. Genetic correlations with litter traits at birth were estimated by using a two-trait linear–linear animal model. Heritability estimates by linear model analysis were low (0.065–0.119 in Landrace & 0.061–0.157 in Large White); those by threshold model analysis were higher (0.136–0.200 & 0.110–0.283). Genetic correlations among parities differed between breeds and models. Genetic correlation between sow stayability and number born alive was positive in many cases, implying that selection for number born alive does not reduce sow stayability. The results seem to be affected by decisions on culling made by farmers.     

绵羊SPP1和PLCB3基因多态性与产羔数的关联分析

试验旨在探究SPP1基因g.36651870T>C位点多态性、PLCB3基因g.41871219T>C位点多态性与绵羊产羔数之间的关系,以期寻找绵羊产羔数性状相关的分子标记.利用全基因组重测序结合Sequenom MassARRAY?SNP技术对多羔羊(小尾寒羊、湖羊、策勒黑羊)和单羔羊(滩羊、苏尼特羊、萨福克羊和草原...