杜洛克公猪背膘厚度、日增重、日采食量和饲料效率相关性状的遗传参数估计

对384头扬翔华系杜洛克公猪生长育肥阶段背膘厚度(BF)、日增重(ADG)、日采食量(ADFI)、饲料转化率(FCR)和剩余采食量(RFI)5个性状用DMU程序进行遗传参数估计探究杜洛克公猪的遗传参数。结果表明, ADFI和RFI的遗传方差占表型方差的比例分别为87.73%和84.91%;BF和ADG的遗传方差占表型方差的比例分别是58.77%和58.91%;RFI与BF、ADG的表型相关系数均为零,而遗传相关系数分别为-0.22和0.15;RFI与ADFI的表型、遗传相关系数分别为0.98和0.99,RFI与FCR的表型、遗传相关系数分别为0.44和0.81。多性状模型与单性状模型的估计遗传力基本趋于一致,ADG和FCR遗传力分别是0.27和0.19,属于低遗传力性状;而BF、ADFI和RFI的估计遗传力在0.31～0.46范围,属于中等遗传力性状。     

扬翔华系杜洛克猪专门化品系生长性状选育

扬翔华系杜洛克是以美系杜洛克和丹系杜洛克为育种素材,通过多个世代持续选育而成的一个瘦肉型猪专门化品系。该研究以扬翔华系杜洛克7个不同世代后备猪为对象,针对其生长性状的选育结果进行分析。结果表明,扬翔华系杜洛克后备公、母猪从第5世代开始,后面3个世代生长速度均显著优于前面各世代(P 0.05),且第7世代后备公、母猪校正115 kg体重日龄分别达到了166.28 d和171.36 d,均显著快于0世代(P 0.05)。后备公、母猪在校正115 kg体重日龄方面的平均世代改良比例分别达到了1.76%和1.72%。在校正115 kg体重背膘厚方面,扬翔华系杜洛克后备公、母猪平均世代改良比例分别达到了1.77%和2.44%。扬翔华系杜洛克在校正115 kg体重日龄及校正115 kg体重背膘厚方面取得较大遗传改良。扬翔华系杜洛克公、母猪达115 kg体重日龄平均每个世代减少2.69 d和2.49 d,115 kg体重背膘厚平均每个世代降低0.15 mm和0.20 mm。文章主要总结了扬翔华系杜洛克猪专门化品系生长性状选育的阶段性成果,为后续研究选育奠定了基础。     

提高猪饲料效率的测定与选择

为提高猪饲料效率的选择,本试验测定一些与猪饲料效率相关的生产性状并进行遗传评估。方法：测定60头军牧1号白猪后备公猪的采食量、体增重、背膘厚等生产性状,用猪剩余采食量（RFI）和饲料转化率（FCR）作为评价饲料效率的两个指标,并对其遗传参数进行评估。结果：测定期内军牧1号公猪群体FCR均值为2．61,RFI的标准差为77．52。RFI与FCR的遗传力分别是0．35、0．33,RFI与ADFI（日采食量）、ADG（日增重）、BF（背膘厚）的遗传相关分别是0．89、0．12、-0．05,FCR与ADFI、ADG、BF的遗传相关分别是0．55、-0．65、-0．11。结论：军牧1号白猪品种内饲料效率存在较大的遗传差异,由于RFI与ADG遗传相关很低,因此用RFI作为选择性状可有效提高猪的饲料效率。     

不同猪品种的饲料转化效率比较分析

本研究选用法系（A群体）和托佩克（B群体）的杜洛克猪290头、长白猪178头、大白猪634头为实验对象,对不同遗传背景猪群体的饲料转化效率（FCE）相关表型性状包括平均日增重（ADG）、平均日采食量（ADFI）、饲料转化率（FCR）、剩余采食量（RFI）、100 kg背膘厚（BF）进行差异比较分析,并对3个生长阶段（30～70 kg、70～100 kg、30～100 kg）的饲料转化效率相关性状进行比较分析。结果表明,30～70 kg阶段猪的生长速度小于70～100 kg和30～100 kg,在B群体的3个生长阶段中,杜洛克猪的ADG高于其他猪种,而FCR低于其他猪种;大白猪的ADG低于其他猪种,而FCR高于其他猪种。3个品种中,30～70 kg阶段杜洛克的FCE在B群体中最高,长白猪的FCE在A群体中最低;在70～100 kg阶段中,大白猪的FCE在B群体中最低;在30～100 kg阶段中,杜洛克猪的FCE高于长白猪和大白猪。在杜洛克猪和长白猪中,低RFI的猪具有更薄的背膘厚。     

扬翔华系杜洛克终端父本后代商品猪生长及屠宰性能分析

杜洛克公猪作为终端父本,其生长速度、屠宰性能等对商品肉猪具有很大的影响。研究选取扬翔华系杜洛克10个家系22头公猪与73头长大二元杂种母猪配种,从后代中选择198头商品猪开展饲养试验,其中12头开展屠宰试验。所有商品猪提供相同的饲粮、饲喂方式、充足的饮水,并在同一养殖场进行饲养。结果显示,以扬翔华系杜洛克公猪作为终端父本,其后代商品猪平均达100千克体重日龄为155.61天,达115千克体重日龄为171.38天,30～100千克日增重达0.88千克,30～115千克日增重达0.99千克,屠宰率达到71%以上,瘦肉率达到65.99%。以上结果表明,扬翔华系杜洛克公猪作为终端父本,其后代商品猪生长速度和屠宰性能均能达到较高的水平,不同家系公猪后代商品猪性能存在差异性(P0.05)。     

扬翔华系杜洛克后代三元杂商品猪生长性能的比较研究

本试验旨在比较扬翔华系杜洛克三元杂商品猪与培育所用素材美系杜洛克三元杂商品猪在生长性能方面的差异。试验选取广西扬翔股份有限公司健康状况良好的杜洛克三元杂商品猪共479头,其中美系杜洛克后代三元杂商品猪366头,扬翔华系杜洛克后代三元杂商品猪113头,按相同饲养标准进行饲养管理,试验期间自由饮水,自由饮食,并进行仔猪初生重、断奶重等相关生长性能的测定。结果表明:扬翔华系与美系杜洛克后代三元杂商品猪的哺乳期生长性能(初生重、校正28日龄断奶重和日增重)与部分育肥期生长性能差异均不显著(P 0.05)。与美系杜洛克后代三元杂商品猪相比,扬翔华系杜洛克后代三元杂商品猪的校正100 kg眼肌面积极显著提高了7.00%(P 0.01),而校正100 kg背膘厚显著降低了5.10%。总体而言,扬翔华系杜洛克公猪配种后代三元杂商品猪生长性能略优于美系杜洛克。     

青年公猪采食习性探究

为了研究青年公猪的采食习性,试验采用全自动生产性能测定系统将102头试验公猪(包括杜洛克猪、长白猪、大约克夏猪)随机分配到8个测定站中,每个测定站12～15头猪,自由采食及饮水,每天定时采集测定系统的前24 h的记录数据并进行显著性分析。结果表明:在30～90 kg以及91～120 kg生长阶段,不同品种公猪日均采食量、日均采食次数、每次采食所需时间均存在较大的差异;91～120 kg阶段的日均采食量较30～90 kg阶段明显提高;在30～90 kg阶段,杜洛克猪每次采食所需时间显著高于大约克夏猪(P0.05),大约克夏猪的日均采食次数显著高于杜洛克猪、长白猪(P0.05);在91～120 kg阶段,杜洛克猪每次采食所需时间、日均采食量均显著高于长白猪、大约克夏猪(P0.05)。3个品种公猪在白天(06:00—18:00)对饲喂器的利用率较高,在50%以上,而在晚上(18:00—翌日06:00)较低。说明品种对采食量、采食次数、每次采食所需时间均存在较大的影响。     

不同品系杜洛克公猪精子品质和形态学比较研究

本文旨在比较扬翔华系杜洛克专门化品系与培育所用素材丹系和美系杜洛克在公猪精子形态和精液品质上的差异,为公猪选育和饲养管理提供参考。试验选取广西扬翔股份公猪站存栏杜洛克3个品系共64头公猪,其中丹系公猪26头,美系公猪30头,扬翔华系杜洛克专门化品系公猪8头。公猪按常规方法采集精液,并利用计算机辅助精液分析系统对精液进行分析。结果表明:在精子密度、活率、正常形态以及总精子数方面,扬翔华系杜洛克专门化品系的杜洛克公猪精液均显著高于美系和丹系的公猪精液(P<0.05);在精子直线运动方面,扬翔华系杜洛克专门化品系与丹系的公猪精液显著高于美系公猪精液(P<0.05),而前两者之间差异不显著(P>0.05);在精子弯尾、卷尾、近端质滴及中端折断方面,扬翔华系杜洛克专门化品系公猪精液均显著低于其他两个品系的公猪精液(P<0.05);在正常精子形状方面,3种品系杜洛克公猪仅在精子头部宽度和面积上存在显著的差异(P<0.05),在其他参数方面均不存在显著差异(P>0.05)。经综合评定,扬翔华系杜洛克专门化品系公猪的精液品质总体表现最佳,美系公猪精液品质次之,而丹系公猪精液品质相对较差,本研究为引进优良公猪及品系的培育提供了一定的参考作用。     

杜洛克猪饲料利用效率测定阶段及RFI校正公式研究

为了解决中国猪育种过程中饲料利用效率测定期长、无校正公式等问题,本研究对应用4种不同方法计算的杜洛克猪全期和不同生长阶段的剩余采食量(RFI)进行了Pearson相关性分析,以得到可代表全期RFI的测定阶段,进而缩短测定时间。应用不同体重RFI线性插值与达100 kg真实体重RFI对杜洛克猪达100 kg体重RFI校正公式参数进行拟合求解,以得到杜洛克猪达100 kg体重RFI校正系数。结果显示,4种方法计算的RFI均为105～180 d生长阶段和全期相关性最高,相关系数均在0.92以上,适配回归方程为:全期RFI=0.9786×(105～108 d测定阶段RFI)+0.0002,最高拟合度为0.9734。杜洛克公猪及母猪达100 kg体重RFI校正系数分别为0.0519和0.0179。在此系数下,公猪70～100 kg范围内校正准确性较高,母猪40～100 kg范围内校正均比较准确。本试验结果可直接用于制定育种方案,既可缩短RFI测定的时间,又可为更准确地计算RFI提供参考,为制定优良的育种方案提供有效数据。     

出生季节和胎次等因素对扬翔华系杜洛克猪生长性能的影响

猪的生长性能受性别、遗传、营养和环境因素的共同影响。分析广西扬翔股份有限公司所属3个种猪场2015—2019年的生猪生长性能数据,研究性别、出生季节、胎次、猪场等因素对扬翔华系杜洛克猪生长性能的影响。发现不同性别扬翔华系杜洛克猪的校正达115 kg体重日龄、校正达115 kg日增重、校正达115 kg背膘厚和校正达115 kg眼肌面积等均差异极显著(P<0.01)。不同季节出生的扬翔华系杜洛克公猪校正达115 kg体重日龄差异极显著(P<0.01);不同季节出生的扬翔华系杜洛克母猪校正达115 kg体重日龄春季和夏季比较差异不显著(P>0.05),秋季和冬季比较差异不显著(P>0.05),但秋季和冬季出生的母猪校正达115 kg体重极显著大于春季和夏季出生的猪。此外,第3胎次出生的猪只校正达115 kg体重日龄最小,校正达115 kg日增重最大且与其他胎次间差异显著(P<0.05);第5胎次出生的猪只校正达115 kg体重日龄最大,校正达115 kg日增重最小且与其他胎次间差异显著(P<0.05)。扬翔华系杜洛克公猪校正达115 kg体重日龄、校正达115 kg日增重、校正达115 kg背膘厚、校正达115 kg眼肌面积在3个不同猪场间差异极显著(P<0.01)。     

Genetic parameters for production traits and measures of residual feed intake in Duroc and Landrace pigs

Data on 380 Duroc boars from seven generations, and 1026 Landrace pigs (341 boars and 685 gilts) from six generations were used to estimate genetic parameters for daily gain (DG), backfat thickness (BF), metabolic weight (MWT), daily feed intake (FI), feed conversion ratio (FCR) and residual feed intake (RFI). Two measures of RFI were estimated as the difference between actual feed intake and that predicted from models that included initial test age and weight and DG (RFI1); and initial test age and weight, DG and BF (RFI2). Heritability estimates for DG, MWT and FI were moderate for both breeds. BF estimates were high for both the breeds. The measures of feed efficiency (FCR and RFI) were moderately heritable. Genetic correlations of BF with measures of RFI were stronger when BF was not included in the estimation of RFI (0.40 and 0.46 for Duroc and Landrace, respectively (for RFI1), compared with 0.05 and 0.06 for Duroc and Landrace, respectively (for RFI2)). Genetic correlations of MWT with measures of RFI were all negative and low. Genetic and phenotypic correlations between DG and measures of RFI were close to zero, which indicated that selection for reduced RFI could be made without adversely affecting DG. BF should also decrease, and MWT should increase under selection for reduced RFI. The reduction in BF would depend on the measure of RFI used.     

Genetic parameters for measures of the efficiency of gain of boars and the genetic relationships with its component traits in Duroc pigs

Genetic parameters for the efficiency of gain traits on 380 boars and the genetic relationships with component traits were estimated in 1,642 pigs (380 boars, 868 gilts, and 394 barrows) in 7 generations of a Duroc population. The efficiency of gain traits included the feed conversion ratio (FCR) and residual feed intake (RFI) and their component traits, ADG, metabolic BW (MWT), and daily feed intake (FI). The RFI was calculated as the difference between the actual and expected FI. The expected FI was predicted by the nutritional requirement and by the residual of phenotypic (RFI(phe)) and genetic (RFI(gen)) regressions from the multivariate analysis for FI on MWT and ADG. The means for RFI(phe) and RFI(gen) were close to zero, and the mean for nutritional RFI was negative (-0.11 kg/d). The traits studied were moderately heritable (ranging from 0.27 to 0.53). The genetic and phenotypic correlations between ADG and FI were moderate to high, whereas the genetic correlation between MWT and FI was moderate, and the phenotypic correlation between them was low. The corresponding correlations between RFI(phe) and RFI(gen) were > 0.95, implying that they can be regarded as the same trait. The genetic and phenotypic correlations of FCR with measures of RFI were high but lower than unity. The RFI(phe) was phenotypically independent of its component traits, MWT (r(p) = 0.01) and ADG (r(p) = 0.03). The RFI(gen) was genetically independent of MWT (r(g) = -0.04), whereas there was a weak genetic relationship (r(g) = 0.15) between RFI(gen) and ADG. Residual FI was more heritable than FCR, and the genetic and phenotypic correlations of RFI(phe) and RFI(gen) with FI were positive and stronger than that of FCR with FI. These results provide evidence that RFI(phe) or RFI(gen) should be included in breeding programs for Duroc pigs to make genetic improvement in the efficiency of gain.     

Genetic parameters for feed efficiency traits and their relationships with growth and carcass traits in Duroc pigs

Genetic parameters for feed efficiency traits of 380 boars and growth and carcass traits of 1642 pigs (380 boars, 868 gilts and 394 barrows) in seven generations of Duroc population were estimated. Feed efficiency traits included the feed conversion ratio (FCR), and nutritional (RFI(nut)), phenotypic (RFI(phe)) and genetic (RFI(gen)) residual feed intake. Growth and carcass traits were the age to reach 105-kg body weight (A105), loin eye muscle area (EMA), backfat (BF), intra-muscular fat (IMF) and meat tenderness. The mean values for RFI(phe) and RFI(gen) were close to zero and for RFI(nut) was negative. All the measures of feed efficiency were moderately heritable (h(2) = 0.31, 0.38, 0.40 and 0.27 for RFI(nut), RFI(phe), RFI(gen) and FCR respectively). The heritabilities for all growth and carcass traits were moderate (ranged from 0.37 to 0.45), except for BF, which was high (0.72). The genetic correlations of RFI(phe) and RFI(gen) with A105 were positive and high. Measures of RFI were correlated negatively with EMA. BF was more strongly correlated with measures of RFI (r(g) > or = 0.73) than with FCR (r(g) = 0.52). Selection for daily gain, EMA, BF and IMF caused favourable genetic changes in feed efficiency traits. Results of this study indicate that selection against either RFI(phe) or RFI(gen) would give a similar correlated response in carcass traits.     

杜洛克猪饲料利用效率测定阶段及RFI校正公式研究

为了解决中国猪育种过程中饲料利用效率测定期长、无校正公式等问题，本研究对应用4种不同方法计算的杜洛克猪全期和不同生长阶段的剩余采食量（RFI）进行了Pearson相关性分析，以得到可代表全期RFI的测定阶段，进而缩短测定时间。应用不同体重RFI线性插值与达100 kg真实体重RFI对杜洛克猪达100 kg体重RFI校正公式参数进行拟合求解，以得到杜洛克猪达100 kg体重RFI校正系数。结果显示，4种方法计算的RFI均为105~180 d生长阶段和全期相关性最高，相关系数均在0.92以上，适配回归方程为：全期RFI=0.9786×（105~108 d测定阶段RFI）+0.0002，最高拟合度为0.9734。杜洛克公猪及母猪达100 kg体重RFI校正系数分别为0.0519和0.0179。在此系数下，公猪70~100 kg范围内校正准确性较高，母猪40~100 kg范围内校正均比较准确。本试验结果可直接用于制定育种方案，既可缩短RFI测定的时间，又可为更准确地计算RFI提供参考，为制定优良的育种方案提供有效数据。     

The relationship between residual feed intake and feed intake behavior in group-housed Duroc barrows

Because feed is the major input in pork production, conversion of feed into lean tissue at minimum costs has been a focus for improvement. Several researchers have proposed using residual feed intake (RFI) rather than feed conversion ratio (FCR) for genetic improvement of feed efficiency. Little is known about the variation in RFI in pigs. As several studies suggest a greater RFI is related to greater animal activity levels, the current study investigated the phenotypic relationship between RFI and feed intake (FI) behavior of 104 group-housed growing Duroc barrows allowed ad libitum access to feed. Feed intake, BW gain, feeding time (TIME), feeding frequency (VISITS), RFI, and FCR were calculated for 5 periods of 14, 23, 28, 21, or 23 d in length (periods 1 through 5, respectively) on animals that were between 73 to 95 d of age at the start of the testing period. Barrows that grew faster consumed more feed (P < 0.001), and barrows that consumed more feed were fatter (P < 0.01). There were no correlations between VISITS and TIME, between VISITS and FI, or between VISITS and RFI. Barrows that spent more time at the feeder, however, consumed more feed (P < 0.05) and had greater RFI in periods 1, 3, and 5 (P < 0.05). As expected, FI and FCR were highly correlated with RFI (P < 0.001). These results suggest that a greater FI rather than greater feed intake activity resulted in greater RFI values.     

Estimation of heritability of feeding behaviour traits and their correlation with production traits in Finnish Yorkshire pigs

A major proportion of the costs of pork production is related to feed. The feed conversion rate (FCR) or residual feed intake (RFI) is thus commonly included in breeding programmes. Feeding behaviour traits do not directly have economic value but, if correlated with production traits, can be used as auxiliary traits. The aim of this study was to estimate the heritability of feeding behaviour traits and their genetic correlations with production traits in the Finnish Yorkshire pig population. The data were available from 3,235 pigs. Feeding behaviour was measured as the number of visits per day (NVD), time spent in feeding per day (TPD), daily feed intake (DFI), time spent feeding per visit (TPV), feed intake per visit (FPV) and feed intake rate (FR). The test station phase was divided into five periods. Estimates of heritabilities of feeding behaviour traits varied from 0.17 to 0.47. Strong genetic correlations were obtained between behaviour traits in all periods. However, only DFI was strongly correlated with the production traits. Interestingly, a moderate positive genetic correlation was obtained between FR and backfat thickness (0.1–0.5) and between FR and average daily gain (0.3–0.4), depending on the period. Based on the results, there is no additional benefit from including feeding‐related traits other than those commonly used (FCR and RFI) in the breeding programme. However, if correlated with animal welfare, the feeding behaviour traits could be valuable in the breeding programme.     

杜洛克猪MAP3K5基因多态位点与生长、饲料利用性状的关联分析

试验旨在研究MAP3K5基因多态性与杜洛克猪生长、饲料利用性状的关联性。利用Illumina SNP60芯片测序结果比较发现了MAP3K5基因的4个SNPs位点（Ssc1：30769583 A>C;Ssc1：30781169 A>G;Ssc1：30940839 A>G;Ssc1：30962276 G>A）。统计获得MAP3K5基因的4个SNPs位点的基因型频率及等位基因频率,发现4个SNPs为低度－中度的多态突变位点。对MAP3K5基因多态性与生长、饲料利用性状的关联性进行分析,结果表明,杜洛克猪Ssc1：30769583 A>C位点CC基因型个体与AA基因型个体相比剩余采食量（RFI）性状降低了133.08 g/d（P<0.05）;Ssc1：30781169 A>G位点的GG基因型个体与AG基因型个体相比RFI性状降低了116.18 g/d（P<0.05）,ADFI性状降低了0.23 kg/d（P<0.05）;Ssc1：30940839 A>G位点的GG基因型个体与AG基因型个体相比饲料转化率（FCR）性状降低了0.10%（P<0.05）;Ssc1：30962276 G>A位点的AA基因型个体与GG基因型个体相比ADG性状降低了0.04 kg/d（P<0.05）。试验初步认为MAP3K5基因4个SNPs位点的多态性对杜洛克猪的RFI、ADFI、FCR和ADG具有一定影响。     

Association Analysis on MAP3K5 Gene Polymorphism Site with Growth and Feed Efficiency Related Traits in Duroc Pigs

This study was aimed to analyze the association of four SNPs of MAP3K5 gene with growth and feed efficiency related traits in Duroc populations. Four SNPs(Ssc1:30769583 A>C;Ssc1:30781169 A>G;Ssc1:30940839 A>G;Ssc1:30962276 G>A)of MAP3K5 gene in Duroc populations were obtained by porcine SNP60 BeadChip（Illumina). The genotype frequency and allele frequency of four SNPs of MAP3K5 gene were analyzed,the result showed that four SNPs were the low-moderate mutation SNPs.The polymorphism of MAP3K5 gene and its association with feed efficiency related traits in Duroc population were analyzed. The results indicated that CC genotype individuals in Ssc1:30769583 A>C had significant lower RFI（133.08 g/d）than AA genotype individuals（P<0.05);GG genotype individuals in Ssc1:30781169 A>G had significant lower RFI（116.18 g/d）and ADFI（0.23 kg/d）than AG genotype individuals（P<0.05);GG genotype individuals in Ssc1:30940839 A>G had significant lower FCR（0.10%）than AG genotype individuals（P<0.05);AA genotype individual in Ssc1:30962276 G>A had significant lower ADG（0.04 kg/d）than GG genotype individuals（P<0.05). All in all,the results suggested that four SNPs polymorphisms of MAP3K5 gene had the significant impact on RFI, ADFI, FCR and ADG traits in Duroc pigs.     

夏季发酵床模式与改进水泥地面模式生猪饲养效果比较

为了比较夏季发酵床与改进水泥地面模式保育猪和生长猪饲养效果,选择日龄相近、生长发育良好的杜×长×大三元配套系商品猪,初始体重分别为（9.59±0.81）kg保育猪88头和（18.43±1.32）kg生长猪64头,随机分成发酵床模式组和改进水泥地面模式组。保育猪饲养期为31d,生长猪饲养期为57d。全程记录饲养期间每天猪舍内温度、湿度、地面温度。结果表明,改进水泥地面模式舍内温度、地面温度和相对湿度均低于发酵床模式。改进水泥地面模式与发酵床模式相比,保育猪日增重提高14.6%、料重比降低11.7%;生长猪日增重无显著差异,但料重比降低9.8%。夏季保育猪和生长猪在改进水泥地面模式下的饲养效果优于发酵床模式,建议南方地区发酵床只用于夏季以外季节的保育猪饲养。