胎次与公猪对巴马香猪产仔数影响及产仔数统计对样本量要求的研究

为研究胎次与公猪对巴马香猪产仔数的影响并分析产仔数统计对样本量的要求,本实验采集了989头巴马香猪历年产仔数,使用Excel、R语言和SPSS19.0分析巴马香猪1～11胎产仔数Person相关系数、各胎次之间的影响差异,并选取159头9胎以上母猪进行可靠性分析;分析巴马香猪公猪与杜洛克公猪对巴马香猪产仔数的影响差异;使用C#编写了Exceltools2.0软件对753头母猪平均产仔数进行以10%样本量为梯度的1～100次随机抽样,计算其变异系数。结果显示:巴马香猪平均产仔数为9.36±2.09头,对胎次的回归方程为Y=8.637+0.167X;第1～9胎产仔数大多相互呈中低度相关,6胎以内相邻胎次之间Person相关系数比更远的胎次间更大;产仔数随胎次增加升高,到8、9胎最高,第1胎的产仔数极显著低于其他胎次;与杜洛克公猪交配能极显著提高巴马香猪的平均产仔数;159头9胎以上母猪与753头母猪各胎次分析结果一致,第2～11胎的平均产仔数与第1～11胎和第3～11胎差异均不显著;抽取1次使变异系数达到1%以下需要的样本量为10%,抽取1次使变异系数达到1‰以下需要的样本量为70%。综上,巴马香猪母猪的可使用年限比其他猪种更长;可以使用第2～11胎平均产仔数作为总平均产仔数或者该品种的平均产仔数;随机抽取70%的母猪计算其平均产仔数准确度极高。     

杜洛克猪品系间杂交效果研究

本研究比较了纯台系和美系杜洛克及其杂交母猪和杂交公猪的生产性能.结果表明,繁殖性能,台美系杜洛克母猪与美系杜洛克公猪回交效果显著好于与台系杜洛克公猪回交,与大白公猪杂交效果最好;生长性能,与美系回交效果要比与台系回交效果好.美系杜洛克公猪交配的母猪窝产仔数(11.88头)比用台系杜洛克交配的母猪(11.54头)略高,但差异不显著;窝产仔数,杂交杜洛克并不比纯系好,但杂交杜洛克公猪20日龄窝产仔数和窝重要比纯系公猪好.两种纯系杜洛克公猪的后代平均日增重相近,但含50%美系和50%台系血液杜洛克公猪后代生长更快,其平均日增重比美系杜洛克公猪和台系杜洛克公猪分别高11.04%和10.37%,差异极显著.台系杜洛克公猪后代的瘦肉率最高,杂种公猪后代肌内脂肪含量比纯系公猪后代的高.美系杜洛克公猪后代的肌内脂肪含量显著高于台系杜洛克公猪后代(1.57%:1.17%).     

不同品种或组合猪多产性研究

本文以 1 2个品种或组合猪为研究对象 ,收集了其 1胎、2胎及经产共 42 6 9窝产仔数和产活仔数的数据资料。纯种猪混合胎次窝产仔数以四川白猪Ⅰ系为最高 ,产仔数和产活仔数分别为 1 1 6 1头和 1 0 71头 ,本地猪、杜洛克猪和长白猪居中 ,分别为 1 0 86头和 1 0 0 6头、1 0 0 7头和 9 33头、9 85头和 9 2 6头 ,大白猪的产仔数和产活仔数最低 ,分别为 9 34头和 8 87头。二杂母猪的窝仔数以DL、DI、YI、DY较高 ,其产仔数和产活仔数分别为 1 1 4 9头和 1 0 80头、1 1 4 8头和 1 0 38头、1 1 36头和 1 0 4 5头、1 0 89头和 1 0 89头 ,YL、YB较低 ,分别为 1 0 2 7头和 9 6 5头、1 0 1 8头和 9 84头。二杂母猪产仔数和产活仔数的平均杂种优势率分别为 8 2 6 %和 9 4 1 % ,其中DL、DI、DY3个组合产仔数和产活仔数的平均杂种优势率分别为 1 1 1 4 %和 1 3 1 3% ,TI、YL、YB相应为 5 39%和 5 6 8%。     

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。     

台系大白猪不同胎次繁殖性能的比较和相关分析

对台系大白母猪核心群不同胎次的繁殖性能进行比较并进行相关分析,结果:台系大白平均产仔数在10头以上,第1胎产仔数最少,从第2胎开始产仔数逐渐上升,第3胎达到较稳定水平,至第5胎达到最高水平。第2、3、5胎的总产仔数、产活仔数均呈极显著正相关,第2、3、5、6胎的初生窝重呈显著正相关。表明台系大白猪第2胎的繁殖性能可以反映后面其他胎次的繁殖性能,而第1胎与其他胎次的繁殖性能无显著相关性,因此第2胎的繁殖性能可以作为台系大白后备母猪选留的重要依据。     

胎次、月份和妊娠期对长白、大约克和杜洛克母猪产仔数的影响

对四川一种猪场的长白、大约克、杜洛克3个瘦肉型品种的2 600窝母猪,在不同品种、胎次、月份和妊娠期下的产仔情况用SPSS软件进行了统计。结果表明:大约克、长白、杜洛克的平均窝产仔数依次为9.96、9.52、9.13头;平均窝产活仔数依次为9.10、8.68、7.74头。通过分析发现这3个品种之间的平均窝产仔数、产活仔数差异不显著(P>0.05)。但是胎次、月份和妊娠期对3个品种平均产仔数的影响均是差异极显著(P<0.01)。     

提高仔猪成活率的技术要点

1能繁母猪的品种 我国优良的地方猪品种具有性早熟、产仔多、耐粗饲等特点,但是瘦肉率低,有待于进一步选育与提高。引进的国外猪品种,瘦肉率较高,生长快,饲料转化率高。长白猪平均产仔数11.1头,约克夏猪平均产仔数10.75头。杜洛克猪平均产仔数9.78头,汉普夏猪平均产仔数8.66头,皮特兰猪平均产仔数9.7头。由于品种造成的产仔数低的因素改变起来相当困难,在生产中应多选择一些繁殖能力强的品种猪作种用,以提高产仔数。     

不同利用方式、分娩季节和胎次对中型梅山猪繁殖性能的影响

为了揭示中梅山猪保种场中梅山猪的繁殖性能,试验以保种有限公司中梅山猪场3年所测的7个繁殖性状为依据,分析不同年份、利用方式、分娩季节和胎次对中梅山猪繁殖性能的影响,统计分析结果显示:中梅山猪1~8胎平均窝产仔数13.61头,产活仔数12.92头,变异系数分别达25.44%和24.08%;中梅山猪4~8胎平均窝产仔数14.76头,产活仔数13.74头,变异系数分别达到25.80%和23.93%,变异程度均较大。纯繁时的窝产仔数和窝产活仔数分别极显著(P0.01)和显著(P0.05)高于杂交,而杂交后20日龄和45日龄窝重极显著地高于纯繁(P0.01)。不同季节窝产仔数、窝产活仔数差异不显著(P0.05),但20日龄和45日龄窝重春夏季显著高于秋冬季(P0.05)。中梅山猪4胎时窝产仔数显著高于1~3胎(P0.05),而与4胎后的其他胎次比较差异不显著(P0.05)。结果表明:中梅山猪繁殖性能好,杂交会降低窝产仔数,4胎时窝产仔数最高,4胎后窝产仔数稳定。     

台系杜洛克杂交组合研究

我场于１９９６年１２月从台湾引进一批台系杜洛克种猪,经过两年的选育表明,该品种猪具有瘦肉率高、饲料报酬高、日增重快、外貌及体型优秀等优点。为了充分发挥其终端父本优势,１９９８年９月,分别以台系杜洛克公猪和匈系杜洛克公猪为终端父本,长大杂母猪为母本进行杂交组合研究,为育种和商品猪的生产提供参考数据。１　材料与方法１．１　试验猪的选择　选择胎次、日龄相近,公母各半,体重４０千克左右的（台系）杜长大９６头为试验组,（匈系）杜长大９６头为对照组。１．２　试验饲料　饲料均采用同一饲料配方与营养水平（见表１…     

内蒙古白塔种猪场几个品种(配套系)猪生产性能测定比较研究

对内蒙古白塔种猪场的4个品种(配套系)猪.分别是白塔配套系猪、法系大白猪、法系长白猪及杜洛克猪从2004-2008年5年的产仔数、健仔数及窝重等3种生产性状进行统计分析,以比较这4个品种(配套系)猪的生产性能的高低、年份对生产性能的影响以及胎次对生产性能的影响,从而研究内蒙古白塔种猪场对种猪的利用效率情况.结果表明,白塔配套系猪、法系大白猪和杜洛克猪的平均窝产仔数都符合1～5胎呈上升趋势、5胎以后呈下降趋势的规律;不同胎次对平均窝产仔数的影响都极显著(P<0.01);4个品种(配套系)平均健仔数都有逐年上升的趋势;而平均窝重都呈逐年下降的趋势.     

香猪基因组外显子SNPs检测及繁殖和体型性状候选基因分析

为从基因组水平上探究香猪性成熟早、产仔数少、体型小的分子机理,本研究下载与香猪在繁殖和体型性状方面有明显差异的梅山猪、杜洛克猪的重测序数据作为参照,对26头香猪、24头梅山猪和24头杜洛克猪的重测序数据进行SNPs检测和等位基因频率差值分析,筛选香猪基因组外显子上与梅山猪、杜洛克猪高度分化的SNPs位点,并使用AS-PCR方法和Sanger测序方法统计其中8个SNPs位点的群体等位基因频率。最后,对含有高度分化SNPs位点的基因进行GO功能富集和KEGG通路分析。结果显示,SNPs检测获得香猪基因组外显子上SNPs共236 710个,包括193个终止密码子丢失、1 238个终止密码子获得、90 945个错义SNPs和144 334个同义SNPs。得到1 046个香猪高度分化SNPs,包括429个错义SNPs、2个终止子丢失、6个终止子获得和609个同义SNPs,影响524个蛋白质编码基因;并发现X染色体上44-58 Mb的一段富含高度分化SNPs的热点区域。群体等位基因频率验证结果与重测序结果一致,鉴定了8个位点均为香猪与梅山猪、杜洛克猪高度分化的SNPs。对524个含有高度分化SNPs的基因进行GO和KEGG分析,富集到卵母细胞减数分裂、雌激素信号途径等繁殖相关通路;GO功能注释到细胞内雌激素受体信号、纤毛运动等繁殖相关条目,骨骼系统形态发生、骨骼发育、成骨细胞分化等体型相关条目。得到含有香猪高度分化SNPs的18个繁殖性状候选基因PTGFR、TRO、DNAH17、PKDREJ、KAT8、DNAI2、VDR、TEX14、QSOX1、AR、WNK3、ADCY3、SPEF1、MIGA2、SLC2A8、PSMF1、TBC1D20、IFT172和7个体型相关基因IBSP、NR6A1、HSPG2、TARS、PDZD2、FGF4、AMER1,可能是决定香猪性成熟早、产仔数少、体型小的关键基因。     

猪VEGF基因5′调控区多态性与产仔数的关联分析

研究通过PCR-SSCP技术对大白猪、长白猪和杜洛克猪共计574头母猪的VEGF基因进行多态分析,并将基因多态性与猪总产仔数(TNB)和产活仔数(NBA)进行关联分析,旨在探讨猪VEGF基因多态性对其产仔数的影响。结果表明:在VEGF 5′调控区内有2个突变位点。P1产物第191位点处由A突变为G,在3个猪品种中只发现AA、AG 2种基因型,其中AG为优势基因型,A为优势等位基因。长白猪第1胎中AG型的TNB和NBA比AA型分别高出1.34头和1.44头(P<0.01),杜洛克猪所有胎次中AG与AA的TNB差异显著(P<0.05),NBA差异极显著(P<0.01)。P2产物第103位点处由C突变为T,在3个猪品种中发现TT、TC、CC 3种基因型,T为优势等位基因。TT、TC分别比CC型的TNB高出2.63头(P<0.05),在杜洛克所有胎次中TC比TT的TNB和NBA分别高出0.84头和0.94头(P<0.05)。P1位点和P2位点能否作为产仔性状的标记基因还需进一步研究。     

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。     

Effect of dietary fibre on reproductive performance of sows during the first two parities

The aim of this study was to investigate the effect of dietary fibre on reproductive performance during the first two parities. Gilts were randomly allocated to receive three fibrous diets from days 1-90 of gestation, including low fibre [low fiber (LF), 10.8% neutral detergent fiber (NDF), n=132], middle fibre [middle fiber (MF), 15.8% NDF, n=132] and high fibre diet (HF, 20.8% NDF, n=135), until completion of the second parity. Response criteria included backfat measurements, litter size and pig weight at parturition and day 22 of lactation, weaning-oestrus-interval, oestrus rate, sow farrowing and culling rate, uniformity of newborns and relative organ weights. The results showed sows fed LF diet in parity 1 gained more backfat (p<0.05) during gestation but lost more (p<0.05) during lactation than sows fed HF diet. Furthermore, sows fed LF diet farrowed more pigs (+0.7-1.1 pigs, p<0.05) and pigs born alive (+1.0 pigs, p<0.05) relative to sows fed HF diet. Likewise, sows fed LF and MF diets had greater litter weights at parturition (both p=0.06) and day 22 after lactation (both p<0.05). In parity 2, yet, it was MF diet to increase both total pigs born and pigs born alive (+0.9-1.1 pigs, p<0.05) and litter weight (p=0.05) relative to other diets. After 22 d of lactation, intriguingly, sows fed HF diet had most pigs alive (p<0.01-0.07) and heavier litter weight (p=0.07 or 0.2). Feeding HF diet also increased internal organs weight of newborns (p<0.05). Collectively, feeding LF and MF diets had beneficial effects on litter weight at parturition and day 22 of lactation in parity 1, and feeding MF diet until parity 2 was able to improve litter size and weight at parturition, but this positive effect disappeared after 22 days of lactation, instead feeding HF diet showed the optimal litter performance.     

初配日龄对母猪产仔性能的影响

根据某猪场淘汰的203头母猪的生产记录,对不同初配日龄母猪的头胎产仔数、产仔胎数及产仔总数进行统计分析。结果表明,240～269日龄的初配母猪头胎产活仔数最少,270～299日龄的初配母猪平均产仔胎数最少,300～329日龄的初配母猪平均产仔胎数和产活仔总数最高,210～239日龄的初配母猪平均产仔胎数最低。从最佳经济效益来看,母猪的最佳初配日龄为210～239日龄。     

猪PRLR和FSHβ基因多态性检测及其与繁殖性状的关联分析

试验旨在研究催乳素受体（prolactin receptor,PRLR）和卵泡刺激素β（follicle-stimulating hormone β,FSHβ）基因的多态性及其与母猪繁殖性状的关联分析。采用PCR-RFLP方法对大白猪、杜洛克猪和长白猪3个猪种共487头母猪进行了PRLR和FSHβ基因多态性检验,并采用单因子方差分析、LSD法分析不同基因型与母猪总产仔数、产活仔数、断奶窝重和断奶窝仔数等繁殖性状的相关性。结果表明,PRLR基因在大白猪和长白猪中B等位基因均为优势基因,基因频率分别为0.717和0.548,大白猪BB基因型总产仔数显著高于AA基因型（P<0.05）,长白猪BB基因型断奶窝重显著高于AB基因型（P<0.05）;FSHβ基因在大白猪、杜洛克猪和长白猪3个猪种中B等位基因均为优势基因,基因频率分别为0.804、0.760和0.789,长白猪BB基因型总产仔数和产活仔数均显著高于AB基因型（P<0.05）,呈现BB>AA>AB趋势。因此,PRLR和FSHβ基因对荣昌猪场母猪繁殖性能有一定影响,可作为母猪繁殖性能分子选育的候选参考基因。     

Lactation feed disappearance and weaning to estrus interval for sows fed spray-dried plasma

Four experiments involving 265, 410, 894, and 554 sows (Exp. 1 to 4, respectively) were conducted to determine the effect of spray-dried plasma (SDP) at 0 or 0.25% (Exp. 1 and 2) and 0 or 0.50% (Exp. 3 and 4) in lactation diets on average daily feed disappearance (FD), sum of sow BW, fetal and placental loss from d 110 gestation to weaning (SWL), litter size at weaning, litter weight at weaning, and average days from weaning to first estrus (WEI). Experiments 1, 3, and 4 were conducted during summer months, and Exp. 2 was conducted during fall to winter months. Experiment 1 used only parity 1 and parity 2 sows and Exp. 4 used only mature (>2 parities) sows, whereas Exp. 2 and 3 used all parity groups. Sows fed SDP in Exp. 1 had increased (P < 0.01) FD and a tendency for reduced (P = 0.06) SWL and WEI (P = 0.06). Sows fed SDP in Exp. 2 had a tendency for increased (P = 0.09) sow BW at weaning and reduced (P = 0.09) SWL, whereas other variables were not different between diets. Parity 1 and 2 sows fed SDP in Exp. 3 had increased (P < 0.01) FD, but mature sows fed SDP had reduced (P = 0.02) FD. Pig survival and litter size at weaning for all parity groups was not different between diets. The WEI for parity 1 sows fed SDP was reduced (P = 0.02) and tended to be reduced (P = 0.10) for mature sows fed SDP, but was not different between diets for parity 2 sows. More parity 1 sows fed SDP were detected (P = 0.01) in estrus 4 to 6 d after weaning, and fewer were detected (P < 0.01) in estrus 6 d after weaning compared with control parity 1 sows. In Exp. 4, FD was reduced (P < 0.01) for mature sows fed SDP; however, litter weight and average pig BW at weaning was increased (P < 0.01) with more (P < 0.01) marketable pigs (pig BW > 3.6 kg) weaned per litter. Relatively low dietary levels of SDP (0.25 to 0.50%) fed to parity 1 sows farrowed during summer months increased lactation FD and reduced WEI. Mature sows fed SDP during summer months consumed less lactation feed without compromising WEI, but had an increased litter weight, average pig BW, and number of marketable pigs at weaning.     

Heterosis and recombination effects on pig reproductive traits

The objective was to estimate breed, heterosis, and recombination effects on pig reproductive traits in two different four-breed composite populations. Breeds included Yorkshire, Landrace, Large White, and Chester White in Exp. 1 and Duroc, Hampshire, Pietrain, and Spot in Exp. 2. Data were recorded on purebred pigs, two-breed cross pigs, and pigs from generations F1 through F6, where F1 pigs were the first generation of a four-breed cross. Litter traits were considered a trait of the gilt. There were 868 first parity litters in Exp. 1 and 865 in Exp. 2. Direct heterosis significantly increased sow weight at 110 d of gestation and litter weight at 14 and 28 d (weaning) in both experiments. Direct heterosis significantly increased number of nipples, weight at puberty, lactation weight loss, litter size, and litter birth weight in Exp. 2. Gestation length in Exp. 1 and age at puberty in Exp. 1 and Exp. 2 were significantly decreased by direct heterosis. Maternal heterosis significantly increased age at puberty in Exp. 2 and decreased sow weight at 110 d of gestation in Exp. 1. Recombination significantly increased sow weight at 110 d of gestation and tended to increase total number born and litter birth weight in Exp. 1. Recombination significantly decreased age at puberty in Exp. 2. Litter heterosis significantly increased number of pigs at 14 and 28 d; litter weights at birth, 14, and 28 d; and tended to increase lactation weight loss in Exp. 1. Litter heterosis decreased litter size in Exp. 2. Maternal heterosis and recombination effects had a sampling correlation of -0.97 in Exp. 1 and -0.91 in Exp. 2 for number of fully formed pigs. Therefore, maternal heterosis and recombination effects were summed, and their net effect was tested. This net effect tended to increase number of nipples, lactation weight loss, and litter birth weight and significantly increased number of fully formed pigs in Exp. 1. Direct, maternal, and litter heterosis and recombination effects significantly influenced reproductive traits.     

Comparative Study of the Lifetime Productivity and Performance Characteristics of Meishan and Duroc Cross-bred Pigs

The objective of this study was to examine the potential of Meishan genotypes to improve production efficiency through increased reproductive performance and sow longevity. Sows of White composite, with either 1/4 Meishan, 1/4 Duroc or 1/8 Duroc were kept for up to six parities and reproductive performance and lifetime productivity of each sow breed was recorded. Progeny from these sows were analysed for growth and carcass characteristics. It was noted that Meishan genotype sows were more prolific (+1 pig/litter -1 ; P <0.05) and had greater longevity in the herd than either of the Duroc genotypes. The growth rate of slaughter pigs from 1/4 Meishan sows was slower than that of either 1/8 or 1/4 Duroc (893, 976 and 931 g day -1 , respectively; P <0.05) and they had poorer carcass lean content (56, 59 and 58%, respectively; P <0.05). The study would suggest that 1/4 Meishan sows may be useful for systems with low costs of production, small penalties for fat carcasses and where gilt replacement costs are high.