靖远某猪场母猪繁殖性能统计分析

母猪繁殖力是影响种猪场经济效益的重要因素。文章对靖远某猪场大白猪、长白猪、杜洛克猪的1 200窝产仔记录进行统计分析,对总产仔数、总活仔数、初生窝重、共3个繁殖性状进行单因素方差分析,分析胎次和品种对母猪繁殖性能的影响。结果表明,胎次对总产仔数、总活仔数、初生窝重的影响极显著(P0.01),而且3个品种的母猪均表现出第一胎产仔数低,2~6胎产仔数最高,7胎以后产仔数开始下降,11胎以上产仔数最低;品种对总活仔数、初生窝重的影响不显著(P0.05),对总产仔数影响极显著,其中大白母猪显著高于长白和杜洛克,杜洛克和长白差异不显著(P0.05)。研究结果为降低非传染性因素造成的种母猪产仔数低的问题以及种猪场对母猪繁殖力的选育提高提供了参考数据和理论依据。     

影响母猪产仔性能因素的分析研究

对山东省某大型种猪场2009--2010年间的1 101窝次的繁殖母猪(包括大白、长白、杜洛克3个品种)的部分繁殖性状进行统计分析,探讨品种、胎次和产仔季节等因素对母猪产仔性能的影响,并分析产仔性状间的相关性.研究结果表明,品种因素对母猪产仔性能有显著影响(P＜0.05),长白猪在窝产仔数和仔猪初生重方面均表现最好,杜洛克猪产仔数最低,但仔猪的初生重显著高于大白猪.胎次因素对母猪产仔性能也有显著影响(P＜0.05),表现为第1胎至第5胎母猪的窝产仔数逐渐增加,经产母猪的产仔数显著高于初产母猪.季节因素显著影响仔猪的初生重(P＜0.05),但对母猪的窝产仔数影响不显著.相关性分析表明,母猪的窝产仔数愈多,仔猪初生重就愈低,并且窝内仔猪初生重的离散性就愈大,即初生仔猪的均匀度愈低.     

不同胎次对齐卡新西兰兔产仔性能的影响

为探讨胎次对母兔产仔性能的影响,研究利用2010~2013年度665只齐卡新西兰母兔前3胎共计1 649窝次的生产性能记录,对不同胎次的产仔性能进行了比较和相关分析。结果表明:胎次极显著地影响母兔的产仔数、产活仔数、初生窝重以及初生个体重(P<0.01);随着胎次的增加,产仔性能逐步上升。进一步的相关分析结果显示,各胎次的产仔性状与前3胎平均值均呈极显著正相关(P<0.01),第3胎的产仔数、产活仔数、死胎数以及初生窝重的相关系数最高;第2胎的产仔数、产活仔数和初生个体重与第3胎呈极显著(P<0.01)或显著(P<0.05)正相关,而第2、3胎间的产仔数和产活仔数差异不显著(P>0.05),表明齐卡新西兰母兔第2胎的产仔性能可以作为总体繁殖性能的评价指标。     

青海八眉猪杂交的繁殖性能研究

为了研究青海八眉猪的繁殖性能,对青海互助八眉猪保种场2011年春季八眉猪经产母猪纯繁和杂交的繁殖性能各指标进行了测定。结果显示:产仔数和产活仔数八眉猪纯繁组显著高于与长白、大白的杂交组(P<0.05);初生重杂交组显著高于八眉纯繁组(P<0.05),初生窝重杂交组虽比纯繁组有所提高,但各组之间差异不显著(P>0.05);21日龄重和21日龄窝重杂交组略高于纯繁组,但各组间差异不显著(P>0.05);断奶重和断奶窝重(长白×八眉)组和(大白×八眉)组最高,显著高于八眉猪纯繁组(P<0.05),但(长白×八眉)组与(大白×八眉)组之间差异不显著(P>0.05);断奶仔数八眉纯繁组略高于各杂交组,但各组间差异不显著(P>0.05)。     

母猪品种、胎次、活仔数和分娩月份对窝产仔均匀度等性状的影响

母猪窝产仔均匀度相关性状是影响哺乳仔猪死亡率的因素之一。本研究对9 458头长白猪和13 317头大白母猪分娩数据进行分析发现,长白和大白猪初生窝内平均重变异度分别为17.9%和18.0%,初生窝内平均重标准差分别为262.6、257.6 g。研究表明,母猪品种、配种组合、母猪产活仔数、胎次、季节及母猪妊娠天数影响母猪窝产仔均匀度。初生窝内平均重标准差依次为大长杂繁(YL)长大杂繁(LY)长白纯繁(LL)大白纯繁(YY)(P0.05);随着产活仔数的增加,初生窝内平均重变异度和标准差显著升高(P0.05);初生窝内平均重标准差和初生窝内平均重变异度均是第1胎最低,随着胎龄而增加。本研究提示通过选择合适的品种、规范胎龄分布和有效的季节性管理措施可以改善猪群窝产仔均匀度。     

胎次、产仔季节和产仔年份对深县猪繁殖性能的影响

为了分析不同产仔季节、胎次和产仔年份对深县母猪繁殖性能的影响,试验根据河北正农牧业有限公司2013—2016年间的深县母猪繁殖记录,采用最小二乘法进行了数据分析。结果表明:产仔季节对深县猪的初生重影响极显著(P0.01),但对其他性状都无显著影响(P0.05);胎次对初生重影响极显著(P0.01),对总产仔数、活仔数、断奶窝重的影响显著(P0.05),总产仔数、活仔数、初生窝重和断奶窝重等均随着胎次的增加而增加;产仔年份对总产仔数、活仔数的影响极显著(P0.01)。     

胎次对母猪产仔性能的影响

根据福建某种猪场的生产记录,应用SPSS软件对不同胎次的3588窝大白、长白和杜洛克纯种母猪的窝产仔数、窝产活仔数等进行统计分析。结果表明,在大白、长白和杜洛克纯种母猪中,胎次对窝产仔数和窝产活仔数的影响极显著(P<0.01),平均窝产仔数、窝产活仔数最高均为第6胎,分别为11.44和10.26头,最少均为第1胎,分别为9.49头和8.56头。     

胎次及配种季节对加系大约克种猪产仔性能的影响研究

试验选用浙江某种猪场2010-2013年出生的加系大约克种猪共4382窝的繁殖性能数据,统计分析不同胎次和配种季节对总产仔数、产活仔数、总死产数、畸形胎数、木乃伊胎数、死胎数和初生窝重的影响。结果表明:胎次对种猪产仔性能有极显著影响(P0.01),母猪1~6胎总产仔数、产活仔数、初生窝重随胎次增加而增加,第6胎达到最高峰,且显著(P0.05)或极显著(P0.01)高于其他胎次;总死产数及死胎数则7~8胎极显著高于其他胎次(P0.01);但胎次对产畸形胎和木乃伊胎数影响不显著(P0.05)。配种季节对种猪产仔性能影响极显著(P0.01),冬季配种的总产仔数,产活仔数,初生窝重显著高于其他配种季节(P0.05);总死产数及死胎数极显著低于其他配种季节(P0.01);但冬季配种产木乃伊胎数极显著高于夏、秋两季(P0.01),显著高于春季(P0.05)。研究表明,加系大约克种猪的最佳产仔胎次为3~6胎,冬季配种的产仔性能明显高于其他配种季节。     

猪3号染色体上与产仔性状和窝内仔猪初生重整齐度显著关联的标记鉴定

试验旨在寻找与猪产仔性状和窝内仔猪初生重整齐度显著关联的分子标记,为猪繁殖性状的遗传改良提供依据。在课题组前期进行的猪全基因组清扫分析的基础上,选定猪3号染色体上的2个SNPs位点（rs338309012和rs335824784）,利用目标序列捕获测序分型技术,在丹系大白猪和美系大白猪群中对这2个SNPs位点与猪产仔性状（包括总产仔数、产活仔数、死胎及木乃伊胎数等）及窝内仔猪初生重整齐度进行关联分析。结果显示,rs338309012位点与总产仔数、木乃伊胎数显著关联（P<0.05）,AC基因型母猪的总产仔数、木乃伊胎数均显著高于CC基因型（P<0.05）;rs335824784位点与有效活仔数、木乃伊胎数显著关联（P<0.05）,与产活仔数和死胎数极显著关联（P<0.01）,不同基因型对产活仔数和有效活仔数的影响为GG > CG > CC,与之相反,对窝内仔猪初生重的变异系数、死胎及木乃伊胎数的影响为GG < CG < CC。因此,rs335824784位点GG基因型猪不仅产活仔数多,而且窝内仔猪初生重整齐,死胎和木乃伊胎数低,可以作为提高猪产仔性状和窝内仔猪初生重整齐度的分子标记。     

影响母猪产仔数和初生重的因素分析

随着现代养猪业的发展,养猪规模越来越大,其繁殖效率也就越容易受到影响而下降,进而影响生产效益,然而提高生产效益的两个关健因素就是精液品质和母猪繁殖力。为了探讨精液品质对母猪繁殖力的影响,本试验统计了河南省驻马店诸美种猪场2006~2013年母猪配种、产仔记录,分析了猪精液质量(精子活率和精子密度)与母猪繁殖力(窝产仔数和初生窝重)的相关性。结果表明:(1)产仔性能最好的是长白猪,大白猪次之,杜洛克猪最差,三个品种的平均窝产仔数分别是10.52头、9.96头、9.05头;第3胎达到最大值,其产仔数分别为11.25头、10.23头、9.57头。(2)精子活率与杜洛克、长白、大白种猪的窝产总仔数、初生窝重呈极显著相关(P0.01)。(3)精子密度与杜洛克、大白种猪窝产总仔数和初生窝重呈极显著相关(P0.01),与长白种猪的没有显著相关(P0.05),表明影响母猪繁殖成绩的关键因素是精子活率。     

二元和三元后备母猪批次化生产技术应用效果分析

本试验于2018年5~10月在天津某猪场对二元(长×大)和三元(杜×长×大)后备母猪应用批次化生产技术后的静立率、淘汰率、妊娠率和窝产仔数等繁殖力指标进行了统计分析。试验分为常温(5—7月)和高温(8—10月)两个阶段,每批参与试验的二元和三元母猪均大于30头。结果表明:在常温季节,三元后备母猪在静立率、妊娠率和总体妊娠率等方面与二元后备母猪无显著性差异(P>0.05);而在高温季节,三元后备母猪的静立率、妊娠率和总体妊娠率等方面均显著低于二元后备母猪(P<0.05)。相对于常温季节,高温季节里二元和三元母猪的妊娠率和总体妊娠率均显著降低,但在静立率方面只有三元母猪显著降低(P<0.05)。不论是在高温季节还是在常温季节,三元后备母猪的窝产仔数和窝均产仔数均显著低于二元后备母猪,而淘汰率却显著高于二元后备母猪(P<0.05)。结论:在常温季节,三元母猪静立率和妊娠率均与二元母猪差异不显著;但在高温季节三元母猪静立率和妊娠率均显著低于二元母猪;不论是高温还是常温季节,三元母猪的窝产仔数都显著低于二元母猪,而淘汰率显著高于二元母猪。     

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。     

大白猪、长白猪和杜洛克猪RBP4基因多态性及其与繁殖性能的相关分析

本试验通过PCR-RFLP技术对大白猪、长白猪和杜洛克猪的视黄醇结合蛋白4(retinol binding protein 4,RBP4)基因第4外显子Msp Ⅰ酶切位点进行多态性分析,并对各基因型母猪的第2、3胎次产仔数、产活仔数、断奶仔猪数、初生窝重、21日龄的窝重及断奶成活率进行测定,进而分析RBP4基因多态性与繁殖性能的关系。结果表明,RBP4基因在3个品种中均存在多态位点;χ²适合性检验表明大白猪在该位点偏离Hardy-Weinberg平衡状态(P<0.05),而长白猪和杜洛克猪在该位点处于Hardy-Weinberg平衡状态(P>0.05)。其中,大白猪中优势基因型为BB基因型,而长白猪和杜洛克猪中优势基因型为AA基因型。在繁殖性能上,长白猪BB基因型群体第2胎总产仔数、产活仔数、断奶仔猪数、初生窝重、21日龄断奶窝重分别高于AA基因型0.97头、1.28头、0.92头、1.74 kg和4.42 kg,高于AB基因型0.92头、1.02头、0.98头、1.43 kg和4.98 kg;第3胎次中总体上BB基因型也为有利基因型。     

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.     

Selection potential of different prolificacy traits in the finnish landrace and large white populations

Heritabilities and genetic correlations for different prolificacy traits were estimated to assess possibilities of selection for high number of piglets weaned. Three litter-size traits: total number of piglets born (TNB), number of piglets born alive (NBA), number of piglets weaned (NW); four piglet survival traits: number of stillborn piglets (NSB), percent of stillborn piglets (NSB%), piglet mortality between birth and weaning (PM), percent of dead piglets during suckling (PM%); and three traits measuring time intervals: age at first farrowing (AFF), first farrowing interval (FFI), and gestation length (GL) were analysed. The Finnish national litter recording scheme provided data on the first parity litters of 11 329 Landrace and 8 362 Large White pigs born between 1986 and 2000. The heritabilitiy estimates were moderate for AFF and GL (0.24–0.37), and low for all the other traits (0.03–0.11). The genetic correlations between TNB and PM (0.68 in Landrace and 0.43 in Large White) and between NBA and PM (0.64 in Landrace and 0.31 in Large White) suggest that selection only for high TNB or NBA will lead to increased PM. The results showed further that GL will increase indirectly if the selection pressure is for low PM (r _g =?0.050 in Landrace and ?0.43 in Large White.     

Estimation of genetic parameters for reproductive traits in connectedness groups of Duroc,Landrace and Yorkshire pigs in China

The objective of this study was to estimate group- and breed-specific genetic parameters for reproductive traits in Chinese Duroc, Landrace, and Yorkshire populations. Records for reproductive traits between April 1998 and December 2017 from 92 nucleus pig breeding farms, which were involved in the China Swine Genetic Improvement Program, were analysed. Due to weak genetic connectedness across all farms, connectedness groups consisting of related farms were used. Three, two and four connectedness groups for Duroc, Landrace and Yorkshire were firstly established according to the genetic connectedness rating among farms. For each connectedness group a five-trait animal model was implemented, and via restricted maximum likelihood procedure the genetic parameters were estimated for five reproductive traits i.e., total number born (TNB), number born alive (NBA), litter weight at farrowing (LWF), farrowing interval (FI) and age at first farrowing (AFF). The average of heritabilities among connectedness groups ranged from .01 (for FI in Yorkshire) to .30 (for AFF in Duroc). Estimates of repeatability for litter traits ranged from .14 to .20 and were consistent for each breed, and for FI, the estimates varied from .01 to .11 across breeds and groups. The estimated genetic correlations among litter traits (i.e., TNB, NBA and LWF) were all significantly high (>.56) and similar across breeds. Averaged genetic correlations over three breeds were −.25, −.27, −.18, −.04, −.10, −.02, and .28 for FI-TNB, FI-NBA, FI-LWF, AFF-TNB, AFF-NBA, AFF-LWF and FI-AFF, respectively. The standard errors of the estimates were all very low (<0.01) in most situations. Results from this study suggest that selection based on TNB which is currently used in dam line selection index can improve NBA and LWF simultaneously. However, care should be taken on FI and AFF as they are both greatly influenced by non-genetic factors such as management and measurement.     

不同配种模式对二元母猪繁殖性能的影响

为探讨不同配种方式对二元母猪产仔数的影响,以杜洛克猪、长白猪、大白猪、皮特兰猪四个品种公猪精液采用人工授精的方法对11654头长大二元母猪配种,对所产11654窝总产仔数、窝产活仔数、窝损失等进行统计和分析,分析不同配种模式对二元母猪繁殖性能的影响。结果表明,配种次数、不同品种公猪组合配种对二元母猪总产仔数、产活仔数以及窝损失均无显著影响（P〉0.05）,但杜洛克公猪所配二元母猪的总产仔数和窝产仔数均高于大白和长白猪（P〈0.05）;采用长×杜×大组合配种的二元母猪总产仔数和窝产活仔数均高于其它三种组合。试验结果表明,在生产中,可在长白、大白、杜洛克猪中任选两个品种,通过二次配种的方式提高母猪的产仔数。     

Effect of candidate gene polymorphisms on reproductive traits in a Large White pig population

The objective of this study was to test for association of candidate single nucleotide polymorphisms (SNPs) with sow prolificacy reproductive traits, such as litter size, ovulation rate and lifetime performance, in gilts of a Large White pig population. Preliminary research on 25 animals selected from the high‐ and low‐performance groups of 347 animals with case‐control studies indicated that seven genes were associated with total number of piglets born (TNB). Six of the seven genes were associated with reproductive traits, including TNB, number of piglets born alive (NBA) and average weight of piglet weaning (AWW). A MBL2 SNP was significantly associated with TNB and NBA in first parity. A CFB SNP was associated with TNB in first parity. An ACE SNP was associated with TNB in first and second parities. An EGF polymorphism was associated with TNB, NBA and AWW in second parity. A KCNC2 polymorphism was significantly associated with TNB and NBA in second parity. A SLC22A5 SNP was associated with TNB and NBA in second parity. Six candidate SNPs were associated with TNB; the only exception was a PRKAG3 polymorphism. A candidate gene approach enables some of these polymorphisms to be used in genetic improvement programs based on marker‐assisted selection.     

Estimation of genetic parameters for farrowing traits in purebred Landrace and Large White pigs

Genetic parameters were estimated for six reproductive traits related to farrowing events in Landrace and Large White pigs; total number born (TNB), number born alive (NBA), number stillborn (NSB), total litter weight at birth (LWB), mean litter weight at birth (MWB), and gestation length (GL). We analyzed 62,534 farrowing records for 10,637 Landrace dams and 49,817 farrowing records for 8,649 Large White dams. Estimated heritabilities of TNB, NBA, NSB, LWB, MWB, and GL by single‐trait repeatability model analyses were 0.12, 0.12, 0.08, 0.18, 0.19, and 0.29, respectively, in Landrace, and 0.12, 0.10, 0.08, 0.18, 0.16, and 0.34, respectively, in Large White. Genetic correlation between NBA and NSB was unfavorable: 0.20 in Landrace and 0.33 in Large White. Genetic correlations of GL with the other five traits were weak: from ?0.18 with NSB to ?0.03 with NBA in Landrace, and from ?0.22 with NSB to ?0.07 with NBA in Large White. LWB had a highly favorable genetic correlation with NBA (0.74 in both breeds), indicating the possibility of using LWB for the genetic improvement of NBA.     

猪骨调素基因多态性对产仔性状的影响1

本文研究了骨调素基因对苏钟猪和二花脸猪繁殖性能的影响。93头母猪660多窝产仔数记录被用来分析骨调素基因型与总产仔数和产活仔数的关系。结果表明,二花脸猪经产总产仔数基因型158/142和170/152、168/140之间差异显著(P<0.05),产活仔数基因型158/142和170/152之间差异显著(P<0.05)。苏钟猪头胎产活仔数基因型164/168和140/152、142/168、152/170之间差异显著(P<0.05),经产总产仔数基因型152/170和130/142之间差异显著(P<0.05)。