母猪配种时背膘厚对繁殖性能的影响

母猪繁殖性能是衡量养猪生产的重要经济指标之一．充分发挥和利用母猪的繁殖性能．是提高猪场经济效益的根本手段。本试验通过研究法系大白母猪配种时背膘厚与总产仔数、产活仔数之间的关系,确定法系大白母猪配种时的最佳膘情．结果表明．法系大白母猪配种时背膘厚18～22mm对繁殖性能有积极影响．过肥和过瘦对总产仔数和产活仔数都有不利影响。     

母猪背膘厚度与其繁殖性能关系的研究

本试验旨在研究母猪背膘厚度与其繁殖性能的关系。试验考察了纯种大白母猪配种时背膘厚度和哺乳期背膘厚度变化对产活仔数、初生窝重及断奶至发情间隔的影响。结果表明,配种时背膘厚度为14.5~19.0mm母猪产活仔数最高,初生窝重最重;不同背膘损失母猪对其断奶至发情间隔无显著影响,但背膘损失较多有增加断奶至发情间隔的趋势。结果提示,母猪中等背膘对其繁殖性能有较好的影响。     

母猪不同时期背膘厚度与繁殖性能关系的研究

试验以198头纯种大白母猪为对象,研究分析了大白母猪在配种前和分娩时背膘厚度与产活仔数、初生窝重的关系,哺乳期背膘厚度变化与断奶至发情时间间隔、下一胎产活仔数、初生窝重的关系。结果表明：大白母猪配种前背膘厚度为15.5-20．0mm时的产活仔数最高,初生窝重也最重;初产大白母猪分娩时背膘厚度为15．5—20．5mm时的产活仔数最高;哺乳期间大白母猪背膘没有损失或者损失较少（〈0．5mm）时的断奶至发情时间间隔最短,下一胎产活仔数最高,下一胎初生窝重也最重。     

二元母猪背膘厚度对繁殖性能的影响

以168头经产长大二元母猪为研究对象,利用超声波背膘仪测量母猪背膘厚度,分析经产二元母猪配种时背膘厚度与窝均产仔数、初生窝重;哺乳期间背膘厚度变化与断乳窝重、断乳至发情时间间隔等指标之间的关系。结果表明哺乳母猪在哺乳期间背膘厚度减少3-6mm时,母猪的发情间隔最短,为5．53＋1．73d;经产母猪配种背膘在14～19mm时,当胎窝均产仔数最高、初生窝重也最重。说明母猪背膘厚对繁殖性能有一定的影响,母猪配种时背膘厚在14～19mm,其繁殖性能较好。     

母猪背膘厚度对其繁殖性能的影响

此文研究分析大白、长白纯种母猪在配种时背膘厚度,经产母猪配种时背膘厚度与窝均产活仔数、初生窝重,哺乳期间背膘厚度减少与断奶窝重、断奶至发情时间间隔等指标之间的关系。结果表明,随着胎次的增加母猪配种时的背膘厚度呈下降趋势,第2胎母猪下降最明显;经产母猪配种时背膘厚度为12.5～18.0mm时,窝均产活仔数最高、初生窝重也最重;哺乳期间母猪背膘厚度减少与仔猪断奶窝重关系不明显,当背膘厚度减少3.0～6.0mm时,断奶至发情时间间隔最短(5.24±0.46)天。     

猪背膘厚与各阶段繁殖性能关系的综述

背膘厚度能最直观地体现母猪的营养水平,而营养水平会影响母猪的繁殖性能。文内对母猪各阶段的背膘厚对其繁殖性能的影响做了综述。文献表明适当的背膘厚度才能使母猪具有更高的繁殖性能。     

母猪背膘厚对其繁殖性能的影响

背膘厚与母猪的繁殖性能息息相关。不同品系母猪的繁殖性能和营养需要差异明显。针对国内饲养的主要母猪体系,比如美系、丹系、加系、法系。笔者认为不同品系母猪同一繁殖阶段的最适背膘厚的标准是有差异的。本文主要从背膘测定方法,以及对不同品系母猪繁殖周期的分娩时、断奶时、后备母猪初配时的3个关键点的最适背膘厚进行综述,以期提高母猪的繁殖性能,为促进养猪行业的发展提供参考。     

背膘厚对母猪繁殖性能的影响

近年来,母猪的年出栏头数随着我国猪场规模化、产业化的进程加快而得到很大提高。母猪的作用就是繁殖仔猪,获取经济效益,其繁殖性能是重要的经济性状之一,但繁殖性能的遗传力低,平均仅0.15,通过表型选择效果不佳;通过分子标记选择进行相关基因的确定,也存在一定困难。所以找到一个简单可行的办法对繁殖性能进行早期估测,具有巨大的实用价值。影响母猪繁殖性能的因素包括遗传、品种、产仔胎次、配种季节、背膘厚等,本文就背膘厚对繁殖性能的影响加以阐述。     

长大经产母猪妊娠期背膘厚对繁殖性能的影响

为探讨长大经产母猪妊娠期不同阶段背膘厚对繁殖性能的影响,试验采用B超仪测定经产母猪配种时、妊娠30 d、60 d、90 d和110 d时的背膘厚,并对测定母猪的总产仔数、产活仔数、健仔数、弱仔数、死胎数、初生窝重和初生个体重进行统计。结果表明：长大经产母猪在配种时保持背膘厚大于16 mm,妊娠前期背膘厚保持在18～20 mm,妊娠后期及临产时背膘厚保持在20～22 mm,母猪繁殖性能最佳。     

母猪背膘厚对其繁殖性能的影响以及调控方法

母猪背膘厚对繁殖性能有重要的影响,与发情、产仔和泌乳都紧密相关。在母猪不同的繁殖阶段根据其背膘厚,可以采取不同的饲养方法来调控其体况,以保证繁殖性能的正常发挥。     

Effect of mixed rearing of barrows and gilts on backfat thickness and serum metabolite profiles of the Kagoshima-Kurobuta (Berkshire) pig

We investigated the effect of mixed rearing of barrows and gilts on the backfat thickness and the serum metabolite profiles of Kagoshima-Kurobuta (Berkshire) pigs. A total of 149 pigs with an average body weight of 35 kg were divided into the following groups: 100%, 90%, 70%, 50%, 30%, 10%, and 0% groups consisting of 10 barrows (1 pen), 9 barrows + 1 gilt (3 pens), 7 barrows + 3 gilts (2 pens), 5 barrows + 5 gilts (3 pens), 3 barrows + 7 gilts (2 pens), 1 barrow + 9 gilts (3 pens), and 9 gilts (1 pen), respectively. All pigs were raised to a shipping weight of 120 kg. Mixed rearing significantly reduced (p < 0.001) backfat thickness, and the optimum mixing ratio of barrows and gilts was 7:3 (the 70% group). Four types of circulating sex steroids were found in both the barrows and gilts in the 50% group but were not detected in barrows from the 100% group. These results indicated that mixed rearing of barrows and gilts was effective for reducing the backfat thickness of barrows, and induced sex steroid hormones may influence the backfat thickness of barrows in mixed-reared groups.     

后备母猪的营养与繁殖

后备母猪的繁殖能力关系到整个猪场的经济效益,其中营养水平和采食量在繁殖方面的影响不容忽视。本文简要叙述了有关营养在后备母猪各个阶段繁殖性能上的影响,以期为我国的养猪生产实践提供一定的帮助。     

托佩克(Topigs)种猪日增重与背标厚选择效果分析

文章对托佩克(Topigs)3个品系5年的日增重和背膘厚性状测定数据作选择效果分析.在对两个性状作遗传参数计算的基础上,明确了这两个性状的遗传力为中等以上,3个品系稍有差异(A系日增重和背膘厚遗传力分别为0.68和0.61;B系分别为0.67和0.48,E系分别为0.48和0.38),同一性状存在阶段性的差别.以此为基...     

深县猪繁殖性状遗传参数的估计

应用动物个体模型和ASReml软件分析109头深县母猪繁殖性状的遗传参数,结果表明:总产仔数、产活仔数、初生窝重、断奶窝重、初生重和断奶重的遗传力分别是0.165、0.024、0.21、0.086、0.018和0.121,性状之间的遗传相关程度差别较大,遗传相关系数在-0.24~0.98之间,表型相关系数在-0.15~0.89之间。结果说明,深县猪的繁殖性能优良,产仔数高但差别大,尚需进一步探究影响繁殖性状的环境和遗传因素。     

群体繁育在南江黄羊品系培育中的应用

通过应用“群系继代、闭锁繁育”法和采取“群内分组、组间轮回”的交配方案，成功培育出南江黄羊高繁品系，并初步建立了具有良好经济性状的快长、大型、黑色类群(系)。高繁品系群体胎平产羔率为220．34％(其中经产羊群为232．81％)，生殖成活率98．74％，断奶成活率94．41％，经产羊产羔间隔为190．96d；快长系(群)六月龄体重公羊30．78kg，母羊26．52kg，六月龄羯羊屠宰胴体重10．46kg，屠宰率48．87％；大型系(群)成年公羊体重和体高分别为69．34kg和76．47cm，母羊分别为47．88kg和66．88cm；黑色类型群(系)羊生长发育和产羔率等性状优于南江黄羊品种定型群体。     

New SNPs in the IGF2 gene and association between this gene and backfat thickness and lean meat content in Large White pigs

IGF2‐in3‐G3072A is a causative mutation for paternally expressed quantitative trait loci on the p arm of porcine chromosome 2 with substantial effect on muscle growth and backfat thickness. The linkage disequilibrium between IGF2‐in3‐G3072A and IGF2‐in7‐G162C (IGF2‐NciI) in four breeds and associations between these polymorphisms and growth and meat performance in pigs of the Large White breed were analysed. A significant effect of these polymorphisms on backfat thickness and lean meat content was found. In addition, we identified two new single nucleotide polymorphisms (SNPs) in intron 7 of the gene. The existence of complete linkage disequilibrium between IGF2‐in3‐G3072A locus in the population under study where the locus segregated and SNPs in intron 7 of the IGF2 gene detectable with simple and reliable polymerase chain reaction–restriction fragment length polymorphism techniques (G162C, C179G and G186T) offer possibilities to use these SNPs for genotyping of quantitative trait nucleotide in Large White and Landrace breeds.     

Effect of selection for backfat thickness in swine on fetal skeletal muscle metabolism

At 110 d of gestation, fetuses were removed from sows selected for high (obese) or for low (lean) backfat thickness. The body weights of lean (1,031 +/- 64 g) and obese (864 +/- 55 g) fetuses were not significantly different. Analysis of muscle composition and of in vitro metabolic characteristics was conducted on the biceps femoris muscle. The percentage of dry weight, protein and glycogen was greater in the muscle of obese fetuses than in the muscle of lean fetuses (P less than .01, P less than .05, and P less than .05, respectively). Percentage of muscle triglyceride was similar (P greater than .05) between the two phenotypes. The rate of glucose oxidation to CO2 tended to be greater (P less than .07) and the rate of lactate production was lower (P less than .05) in the muscle from obese fetuses than in the muscle from lean fetuses. The rates of leucine oxidation to CO2 and of palmitate oxidation to CO2 did not differ between phenotypes. The rate of alpha-ketoisocaproate release from the muscle of obese fetuses was greater (P less than .05) than from that of the lean fetuses. The rate of release of alanine and of glutamine plus glutamate did not differ between phenotypes. The rate of esterification of palmitate did not differ between phenotypes. It was concluded that abnormalities in glucose metabolism and in the partitioning of leucine between oxidation and release as the keto acid existed at 110 d of gestation in the muscle of obese fetuses. Any relation between these differences and ultimate differences in carcass composition were not evident.