猪血浆蛋白多态性预估亲种优势的探讨

利用聚丙烯酰胺凝胶垂直平板电泳法测定了杜长大、大杜长大、大长大、长大、杜洛克等５个品种组合的转铁蛋白、后白蛋白、后转铁蛋白、血液结合素、淀粉酶的多态性。根据这些位点基因频率计算了基因平均杂合度,对这些品种组合的基因平均杂合度与主要经济性状以及主要经济性状的杂种优势率进行了相关分析。结果表明,平均杂合度与日增重、屠宰率和瘦肉率间存在非常显著或显著正相关,平均杂合度与日增重杂优率、屠宰率的杂优率间也有     

猪配套系生长性状基因效应与杂种优势的分析

测定杜长大三元杂交体系和斯格配套系各杂交组合的生长性能,计算出生长性状的杂种优势率;选用5个与生长性状紧密连锁的微卫星标记对测定个体进行基因型检测,利用混合效应线性模型计算出生长性状各位点的基因效应。结果显示:斯格配套系父母代与商品代各时期的平均日增重的差异均达到极显著水平(P<0.01),杜长大杂交体系父母代与商品代各时期的平均日增重的差异均达到显著水平(P<0.05),斯格配套系父母代和商品代与杜长大杂交体系的父母代和商品代的差异达到极显著水平(P<0.01),前期的的杂优率处于较高水平,后期及全程的杂优率不高。基因效应分析显示早期日增重的基因效应既有加性效应又有显性效应,后期日增重和全程日增重的加性效应明显,因而加性效应是日增重杂种优势的主要遗传学基础。     

杜洛克、大白、长白猪的生长和肉用性状杂交效果研究

为筛选优化杂交组合,进行了杜洛克（杜）、大白（大）、长白（长）品种间杂交试验,测定了不同品种组合的生长速度、饲料转化率、胴体和肉质性状及其杂种优势率。结果表明,杜洛克、父系大白猪作终端父本与长大杂母猪杂交,其后代的日增重、饲料转化率、屠宰率、胴体长、眼肌面积、后腿比例、瘦肉率及肉质等主要性状均无显著差异。     

利用AFLP标记遗传距离预测猪经济性状杂种优势的研究

利用扩增片段长度多态性(AFLP)标记,测定6个亲本群体间的遗传距离,并对亲本群体间遗传距离与6个经济性状的杂种优势率相关关系进行分析。结果表明:亲本间遗传距离与日增重、饲料转化率、屠宰率和平均背膘厚的杂种优势率呈正相关,与瘦肉率、眼肌面积的杂种优势率呈负相关;亲本群间AFLP标记遗传距离与杂种优势的相关程度因性状不同而异。     

不同杂交组合猪肥育性能的比较研究

本试验通过对长×大（L×Y）、杜×长大（D×LY）、皮杜×长大（PD×LY）3个杂交组合猪的生长肥育、胴体品质及肉质性状进行研究，结果表明：PD×LY杂交组合的日增重、料肉比及屠宰率最优，日增重、屠宰率与L×Y组间差异显著（P＜0.05）；PD×LY的眼肌面积、后腿比例分别为48.09 cm2、34.23%，为3组合中最高，与L×Y组的差异显著（P＜0.05)，与D×LY组的差异不显著（P＞0.05）； D×LY组的肉色评分、嫩度测定结果最佳，组间差异显著（P＜0.05）；PD×LY组的失水率、熟肉率、嫩度最差，其中熟肉率、嫩度与其它组间差异显著（P＜0.05)。综合评定：导入皮特兰猪的血液在提高了日增重、屠宰率、眼肌面积、后腿比例等性状的同时，却导致了肉质的下降; D×LY作为一个经典的杂交组合，生产性能总体稳定。     

猪血清蛋白多态性与杂种优势关系的探讨

本研究通过血清蛋白多态性 ,分析撒坝猪与杜洛克、长白及约克夏的基因平均杂合度与遗传距离 ,分析遗传距离与杂交组合试验资料表明 ,撒坝猪与杂交品种间遗传距离大时 ,杂交组合的达屠宰体重 (90kg)日龄、饲料转化率、日增重、瘦肉率的杂种优势大 ;反之 ,遗传距离小时 ,其主要经济性状的杂种优势相应较小 ,杂交组合间的遗传距离与杂种优势趋势是一致的 ,因而可用于杂种优势的预测。     

新美系猪选育群及其杂交组合的杂交效果分析

试验共设6个组,包括杜、长、大三个纯种组和长×大、大×长、杜×长大三个杂交组,每组选取健康的、体重约25 kg的试验猪12头,公母各半,经过预饲调整后每组选取10头开始正式试验。饲养至组平均体重达100 kg左右时,每组选取4头（2♂2♀）进行屠宰测定和肉质分析,并计算了三个杂交组猪的各主要经济指标的杂优率（H）。结果表明,目前选育群各品种猪的日增重830 g以上,料肉比2.53以下,瘦肉率67%以上,肉质优良。三个纯种组中生长速度以杜洛克为最快,平均日增重达912 g;料肉比以大白猪的最低,为2.35;长白猪的屠宰率、胴体斜长、眼肌面积、瘦肉率最高,背膘厚最薄;6个组中杜×长大商品猪生长最快,平均日增重达977 g,料肉比为2.34,并有较理想的杂优率,而相对于长×大和大×长组合而言,许多重要经济性状,如背膘厚、眼肌面积、后腿比例、脂率、贮存损失等,大×长的杂优率均优于长×大,表明大×长组合也是非常有效的杂交组合,可为筛选新的杂优组合提供参考依据。     

猪杂交配套系杂种优势利用分析

比较了杜长大杂交繁育体系与斯格配套系各纯系和杂交组合的生产性能,结果显示,斯格祖代猪与父母代猪产仔数、产活仔数、断奶仔数、断奶窝重的差异均达到极显著水平,父母代猪与祖代猪的初生窝重差异显著;斯格父母代猪的产仔数、产活仔数、断奶仔数和断奶窝重与长大母猪的差异均达到极显著水平,斯格父母代猪与长大母猪的初生窝重差异显著。繁殖性状的杂优率处于小到较高水平,斯格配套系父母代与商品代各时期平均日增重的差异均达到极显著水平,杜长大杂交体系父母代与商品代各时期平均日增重的差异均达到显著水平,斯格配套系父母代和商品代与杜长大杂交体系父母代和商品代日增重的差异均达到极显著水平,日增重具有中等杂优率。     

不同杂交方式的杂交效果比较

根据大约克夏（大）、长白（长）、杜洛克（杜）的两次杂交试验结果，比较了三品种杂交（杜×长大）、回交（大×长大）、两品种杂交（长×大）的杂交效果。结果表明，在平均日增重、料重比、眼肌面积、瘦肉率等主要性状的杂种优势率上，表现出三品种杂交优于回交，回交又优于两品种杂交的总趋势。     

多系配套杂交群体遗传结构分析

利用8个微卫星标记对杜长大三元杂交群体5个种群，斯格配套系8个种群的遗传结构进行了分析。通过计算等位基因频率、基因杂合度、平均杂合度、多态信息含量、纯种间的遗传距离、F-统计量和迁移率进行分析。结果表明各群体的平均基因杂合度存在一定差异。纯种、祖代、父母代、商品代群体的平均座位杂合度和多态信息含量随着群体在杂交繁育体系中位置的由高到低而逐渐升高。Nei氏标准遗传距离显示，父本和母本间的遗传距离大，遗传距离大的父本和母本用于杂交，产生的杂种优势最大，这与实际的杂交组合一致。Fst衡量等位基因频率群体间方差，杜长大群体大约总变异的1．02％～15．60％来自种群间，而剩余的84．40％～98．98％来自种群内，斯格群体大约总变异的3．02％～15．22％来自种群间，而剩余的84．78％～96．98％来自种群内，斯格和杜长大纯种的遗传分化处于较小到中等之间。     

Effect of replacing soybean protein by taro leaf (Colocasia esculenta (L.) Schott) protein on growth performance of exotic (Landrace × Yorkshire) and native (Moo Lath) Lao pigs

The impact of replacing soybean crude protein (CP) with CP from ensiled taro leaves (ET) on growth performance, carcass traits, and organ weights in Landrace × Yorkshire (LY) and Moo Lath (ML) Lao pigs was studied. Twenty-four castrated male pigs, 12 of each breed, were allocated to the treatments according to a completely randomized 3?×?2 factorial (three levels of ET × two breeds) arrangement with four pigs per treatment. The pigs were kept in individual pens and were fed at 4 % dry matter of body weight for 105 days. The control diet (ET0) was formulated with soybean meal as the main CP source, and in the other two diets, soybean CP was replaced to 25 % (ET25) and 50 % (ET50), respectively, with CP from ensiled taro leaves. Calculated metabolizable energy intake decreased with increasing replacement of soybean CP in the diet, while dry matter intake (DMI), CP intake (CPI), average daily gain (ADG), and feed conversion ratio (FCR) were unaffected. Carcass weight, back fat thickness, and dressing percentage were unaffected by soybean CP replacement, while organ weights (except for spleen) increased (P?<?0.001) when soybean CP was replaced by CP from ensiled taro leaves in the diet. LY pigs had higher (P?<?0.001) DMI, CPI, and ADG and better (P?<?0.001) FCR than ML pigs. LY pigs had higher carcass weight (P?<?0.001), lower back fat thickness (P?<?0.001), and higher organ weights (P?<?0.05–0.001) than the ML pigs. In conclusion, taro leaf silage can replace up to 50 % of soybean CP in the diet of growing Lao LY and ML pigs without negative effects on performance and carcass traits.     

Effect of replacing soybean protein with protein from ensiled stylo (Stylosanthes guianensis (Aubl.) Sw. var. guianensis) on growth performance, carcass traits and organ weights of exotic (Landrace × Yorkshire) and native (Moo Lath) Lao pigs

The present study examined the impact of replacing crude protein (CP) from soybean with CP from ensiled stylo (ES) on growth performance, carcass traits and organ weights in Landrace × Yorkshire (LY) and Moo Lath (ML) native Lao pigs. Twenty-four castrated male pigs, 12 of each breed, were allocated to the diet treatments according to a completely randomised 3?×?2 factorial (three ES levels × two breeds) arrangement, with four pigs per diet treatment. Pigs were kept in individual pens and fed at 4 % dry matter of body weight for 98 days. The control diet was formulated with soybean meal as the main CP source, and in the other two experimental diets, CP from soybean was replaced at 25 % (ES25) and 50 % (ES50) by CP from ES. Calculated metabolisable energy intake decreased with ES50 diet, while dry matter intake (DMI) and CP intake (CPI) were the highest in ES25 diet (P?<?0.001). Overall, average daily gain (ADG) and feed conversion ratio (FCR) were unaffected by diet treatments. Carcass weight, backfat thickness and dressing percentage were unaffected by soybean CP replacement, while the weights of lung, large intestine and stomach were higher (P?<?0.001) when 25 % of soybean CP was replaced by CP from ES. LY pigs had higher (P?<?0.001) DMI, CPI and ADG and poorer (P?<?0.001) FCR than ML pigs. LY pigs had higher carcass weight (P?<?0.001), lower backfat thickness (P?<?0.001) and higher organ weight (P?<?0.001) than ML pigs, except for small intestine weight, where there was no difference between the LY and ML pigs (P?>?0.05). In conclusion, ES can replace up to 50 % of soybean CP in the diet of growing Lao LY and ML pigs without negative effects on performance and carcass traits.     

二花脸猪与杜洛克猪大约克猪杂交利用的初步研究

<正> 一、研究目的 二花脸猪是太湖猪的一个类群,以繁殖性能高、肉质鲜美而著称于世,但育肥性能和胴体品质较差。猪的经济性状视其遗传力的高低有不同的改良途径。本文旨在研究以二花脸猪作母本的杂交组合试验,分析杂种优势在繁殖性能、育肥、胴体等性状上的表现,筛选最佳组合,为二花脸猪的利用提供科学的依据。     

饲粮中添加绿狐尾藻对肥育猪生长性能、血清生化指标和胴体品质的影响

本试验旨在研究饲粮中添加绿狐尾藻对肥育猪生长性能、血清生化指标和胴体品质的影响。采用单因素完全随机试验设计,选用40头初始体重为(55.20±2.18)kg的健康"杜×长×大"三元杂交猪,随机分为4个组,每组10个重复,每个重复1头猪。Ⅰ组(对照组)饲喂基础饲粮,Ⅱ、Ⅲ和Ⅳ组饲粮在基础饲粮中分别添加5%、10%和15%绿狐尾藻,试验期60 d。结果表明:1)与对照组相比,Ⅱ和Ⅲ组肥育猪的终末体重、平均日增重和料重比均无显著差异(P0.05);Ⅳ组的终末体重和平均日增重显著降低(P0.05),料重比显著增加(P0.05)。2)各组肥育猪的血清总蛋白、尿素氮、总胆固醇、甘油三酯、低密度脂蛋白、高密度脂蛋白含量和谷草转氨酶活性均无显著差异(P0.05);与对照组相比,Ⅲ组的血清谷丙转氨酶活性和Ⅳ组的血清白蛋白含量显著降低(P0.05)。3)各组肥育猪的胴体率、瘦肉率、屠宰率、胴体斜长、肉色、剪切力和大理石纹评分均无显著差异(P0.05);与对照组相比,Ⅲ和Ⅳ组的平均背膘厚和Ⅳ组的眼肌面积显著降低(P0.05),Ⅲ组的滴水损失有降低趋势(P0.05),Ⅱ和Ⅲ组的p H45 m in、p H24 h有增加趋势(P0.05)。由此可见,饲粮中添加10%绿狐尾藻对肥育猪的生长性能无显著影响,可改善血清生化指标,降低平均背膘厚,减缓肌肉p H下降速度,降低滴水损失,改善猪肉品质。     

日粮中添加不同比例的牧站1号王草益生菌发酵饲料对黑猪生产性能及养殖效益的影响

旨在研究5种比例的牧站1号王草益生菌发酵饲料对黑猪生产性能及养殖效益的影响。选择体重相近、健康状况良好的二元杂黑猪180头,随机分为6组,每组3次重复,每个重复10头。对照组饲喂基础日粮,试验Ⅰ组、Ⅱ组、Ⅲ组、Ⅳ组、Ⅴ组分别在基础日粮中添加10%、20%、30%、40%、50%牧站1号王草益生菌发酵饲料。饲喂试验预试期7 d,正试期60 d,计算并比较各组试验猪平均日增重、平均日采食量、腹泻率、屠宰率及养殖毛利润。试验结果表明：试验组与对照组比较,Ⅲ组试验猪平均日增重差异不显著（P>0.05）,其他试验组试验猪平均日增重差异显著（P<0.05）,最高为Ⅱ组（865.24 g/头）,高于对照组23.24%,其次是Ⅰ组（839.33 g/头）,高于对照组19.55%,最低为Ⅴ组（552.51 g/头）,低于对照组21.31%;平均日采食量最大为Ⅴ组（3.35 kg/头）,最小的为对照组（2.30 kg/头）,各试验组与对照组比较,差异显著（P<0.05）;屠宰率方面,Ⅰ组、Ⅱ组差异不显著（P>0.05）,Ⅲ组、Ⅳ组、Ⅴ组差异显著（P<0.05）,屠宰率随着牧站1号王草益生菌发酵饲料添加量的增加呈降低趋势,最高为对照组,最低为Ⅴ组;毛利润最高的为Ⅱ组（21 259.0元）,最低的为Ⅴ组（10 325.7元）。育肥黑猪日粮中添加 20%牧站1号王草益生菌发酵饲料生产性能及经济指标影响效果最佳。     

饲粮异亮氨酸水平对肥育猪生长性能、胴体性状和肉品质的影响

本试验旨在研究饲粮异亮氨酸水平对肥育猪生长性能、胴体性状和肉品质的影响。选取体重为(77.0±0.1)kg的杜×长×大三元杂交去势公猪72头,随机分为3组,每组6个重复,每个重复4头猪。3组试验猪分别饲喂含0.25%(低异亮氨酸水平,表现为异亮氨酸缺乏,L-Ile组)、0.39%(NRC推荐异亮氨酸水平,N-Ile组,作为对照组)和0.53%(高异亮氨酸水平,表现为异亮氨酸超量添加,H-Ile组)标准回肠可消化异亮氨酸的饲粮。试验期为28 d。结果表明:饲粮异亮氨酸水平对肥育猪的平均日增重和平均日采食量没有显著影响(P0.05),但L-Ile组料重比较对照组显著增加(P0.05);随着饲粮异亮氨酸水平的增加,肥育猪背最长肌肌内脂肪含量线性提高(P0.05),而剪切力线性下降(P0.05);与对照组相比,采食异亮氨酸缺乏饲粮的肥育猪的背膘厚、眼肌面积和肉色评分显著降低(P0.05),采食异亮氨酸缺乏或超量添加饲粮的肥育猪的热胴体重、屠宰率以及背最长肌滴水损失和黄度值均显著降低(P0.05);随着饲粮异亮氨酸水平的增加,血清甘油三酯含量线性提高(P0.05),血清尿素氮含量线性下降(P0.05);与对照组相比,采食异亮氨酸超量添加饲粮的肥育猪的血清葡萄糖含量显著增加(P0.05),采食异亮氨酸缺乏饲粮的肥育猪的血清中游离的必需氨基酸、非必需氨基酸和总氨基酸的浓度显著降低(P0.05),而采食异亮氨酸缺乏或超量添加饲粮的肥育猪血清总胆固醇、低密度脂蛋白和高密度脂蛋白含量均显著降低(P0.05)。由此得出,饲粮中异亮氨酸缺乏对肥育猪生长性能、胴体性状和肌内脂肪含量有负面影响,而超量添加异亮氨酸会显著改善肌肉的剪切力和滴水损失,增加肌内脂肪含量,但会以降低热胴体重、屠宰率为代价。     

松辽黑猪IGF-Ⅰ基因外显子4多态性及与部分生产性能的关系

以IGF-Ⅰ基因作为松辽黑猪生长和胴体性状的候选基因，采用PCR-SSCP方法检测30头松辽黑猪IGF-Ⅰ基因外显子4(179 bp)的多态性，对该基因的不同基因型与生长和胴体性状的关系进行分析。结果表明，IGF-Ⅰ基因的2个等位基因和3种基因型在松辽黑猪中均有不同频率的分布，遗传多态性较高; IGF-Ⅰ不同基因型对断奶后日增重有显著影响，AA型显著高于AB型和BB型(P<0.01)。AA型猪的瘦肉率显著低于AB型和BB型(P<0.01)，而AA型猪的平均背膘厚显著高于AB型和BB型(P<0.01)，对其它性状的影响差异不显著。因此，IGF-Ⅰ基因的遗传分析结果说明该基因对松辽黑猪的平均日增重、瘦肉率和平均背膘厚等3个性状有显著的遗传影响，可以初步推断IGF-Ⅰ基因可能是影响猪生长和胴体性状的一个主效基因或是一个与影响猪生长和胴体性状的QTL连锁的基因。     

不同类型肥育猪生长性能及胴体性状的研究

作者主要探讨不同类型猪在生长性能与肌肉品质的差异。挑选50 kg 左右的鄂西黑猪(脂肪型)、长大二元杂交猪(瘦肉型)、长♂×(野♂×鄂♀) ♀(中间型)三元杂交阉公猪各24头,饲养至100 kg左右屠宰,每个品种屠宰6头,进行生长性能、胴体性状与肉质性状的测定。研究结果表明,长大二元杂交猪的生长速度显著高于鄂西黑猪(P<0.05),而与长野鄂杂交猪差异不显著(P>0.05)。长大二元杂交猪的屠宰率、瘦肉率和眼肌面积显著高于鄂西黑猪和长野鄂杂交猪(P<0.05),而料重比、背膘厚显著低于鄂西黑猪(P<0.05)。长大二元杂交猪的肌肉pH2、滴水损失和剪切力显著高于鄂西黑猪,而肌肉评分显著低于鄂西黑猪(P<0.05),而长野鄂杂交猪的肉质与长大二元杂交猪和鄂西黑猪差异均不显著(P>0.05)。     

Effects of dietary protein/energy ratio on growth performance,carcass trait,meat quality,and plasma metabolites in pigs of different genotypes

Background:The protein/energy ratio is important for the production performance and utilization of available feed resources by animals.Increased protein consumption by mammals leads to elevated feed costs and increased nitrogen release into the environment.This study aimed to evaluate the effects of dietary protein/energy ratio on the growth performance,carcass traits,meat quality,and plasma metabolites of pigs of different genotypes.Methods:Bama mini-pigs and Landrace pigs were randomly assigned to two dietary treatment groups(Chinese conventional diet with low protein/energy ratio or National Research Council diet with high protein/energy ratio;n = 24 per treatment) in a 2x2 factorial arrangement.Blood and muscle samples were collected at the end of the nursery,growing,and finishing phases.Results:We observed significant interactions(P 0.05) between breed and diet for total fat percentage,intramuscular fat(IMF) content,protein content in biceps femoris(BF) muscle,and plasma urea nitrogen(UN) concentration in the nursery phase;for average daily gain(ADG),average daily feed intake(ADFI),dry matter,IMF content in psoas major(PM) muscle,and plasma total protein and albumin concentrations in the growing phase;and for drip loss and plasma UN concentration in the finishing phase.Breed influenced(P 0.05) growth performance,carcass traits,and meat quality,but not plasma metabolites.Throughout the trial,Landrace pigs showed significantly higher(P 0.05) ADG,ADFI,dressing percentage,lean mass rate,and loin-eye area than did Bama mini-pigs,but significantly lower(P 0.05)feed/gain ratio,fat percentage,backfat thickness,and IMF content.Dietary protein/energy ratio influenced the pH value,chemical composition of BF and PM muscles,and plasma activities of glutamic-pyruvic transaminase and gamma-glutamyl transpeptidase,and plasma concentration of UN.Conclusions:Compared with Landrace pigs,Bama mini-pigs showed slower growth and lower carcass performance,but had better meat quality.Moreover,unlike Landrace pigs,the dietary protein/energy ratio did not affect the growth performance of Bama mini-pigs.These results suggest that,in swine production,low dietary protein/energy ratio may be useful for reducing feed costs and minimizing the adverse effects of ammonia release into the environment.