限制与自由采食条件下猪主要性状遗传和表型参数的研究

Studies on the Genetic and Penotypic Parameters of Some Traits in Swine Raised with Restrictcd and Ad Libitum Feeding:

猪的生长速度、饲料转化率和胴体质量是主要生产经济指标,也是重要的育种改良性状。了解这些性状在不同饲养条件下的遗传和表型参数,可为育种选择工作提供依据。本文对自由采食和限制喂料两群猪的平均日增重(DG)、日采食量(FI)、饲料转化率(FCR)、P_2点背瞟厚(BF)和后腿瘦肉量(HL)作了遗传分析和比较。试验猪为合成品系,其主要遗传成份为大白猪和长白猪以及少量巴克夏猪。分析结果:限制采食猪各性状的平均数和标准差为:DG729±48.45g,FI1.85±0.043kg,FCR2.56±0.15,BF15.3±1.90mm,HL6.07±0.36kg;自由采食猪依次为821±85.87g,213±0.16kg,2.85±0.31,16.8±2.43mm和6.07±0.56kg。限制采食猪各性状的遗传力为:DG0.399,F10.410;FCR0.403,BF0.619,HL0.446;自由采食猪依次为0.307,0.480,0.129,0.315和0.350。在限制采食下,DG与FCR、HL;FCR与HL之间有很强的遗传相关,相关系数分别为-0.94,0.95和-0.97;而在自由采食下,这三个相关系数则依次为-0.46,0.97和-0.46。

The growth rate, feed conversion ratio and the carcases quality of swine are not only the major economic criteria of swine production but the important traits for the swine improvement. To understand the genetic and phenotypic parameters of these traits under the different environment conditions can provide the scientific basis for the breeding and selection of the swine.The paper describes the genetic analysis and comparisons of the traits including average daily gain (DG), daily feeding intake (FI), feed conversion ratio (FCR), backfat thickness on P_2 points (BF) and ham lean weight (HL). The swine for the experiment were the offsprings of a systhetic line, mostly from Large White, Landrace and a small proportion from Berkshire.The results of analysis indicated that the means and standard deviation of these traits of the swine fed with restricted feeding were: DG 729±48.45g; FI1.8±0.043kg; FCR2.56±0.15; BF15.3±1.9mm; HL6.70±0.36kg respectively while those with ad libitum feeding, 821±85.07g; 2.3±0.16kg; 2.85±0.31; 16.8±2.43mm and 6.07±0.56kg correspondingly in sequence.The heritabilities of these traits of group with restricted feeding were: 0.399 (DG), 0.410 (FI), 0.403 (FCR), 0.619 (BF)and 0.446 (HL), while that of the group with ad libitum feeding were 0.307 (DG), 0.480 (FI), 0.129 (FCR), 0.315 (BF) and 0.350 (HL) respectively.Highly genetic correlations were found between average daily gain and feed conversion ratio (r=-0.94), between daily gain and ham lean weight (r= 0.95), and between feed conversion ratio and ham lean weight (r=-0.97) in the group fed with restricted feeding.The correlation coefficient of the corresponding parameters in the group fed with ad libitum feeding were -0.46, 0.97 and -0.46 respectively.