Engblom L, Lundeheim N, Schneider M Del P, Dalin A-M, Andersson K
1Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, PO Box 7023, SE-750 07 Uppsala, Sweden.
Animal. 2009 Jun;3(6):783-90. doi: 10.1017/S175173110900411X.
The aim of this study was to estimate genetic parameters for longevity from Swedish crossbred sows to investigate the possibilities of selecting for this trait. Data were collected from 16 commercial piglet-producing herds, on crossbred (Landrace × Yorkshire) sows farrowing in the period 1 January 2001 to 31 December 2004. The data set with records on 10 373 sows was split into two sets according to the breed of the sire, i.e. Landrace sires (LS) or Yorkshire sires (YS). Removal hazard during productive life (PL) was analysed with survival analysis, using a sire model. Stayability from first to second litter (STAY12), stayability from first to third litter (STAY13), length of productive life (LPL) and lifetime production (LTP) were analysed with linear models, using an animal model. Females after the worst sire had 1.7 times higher (progeny of LS) and 2.4 times higher (progeny of YS) risk of removal than females after the best sire. Heritability for PL was estimated at 0.06 (LS) and 0.12 (YS). The heritabilities for the linear longevity traits ranged from 0.03 to 0.08. Genetic correlations between the four linear longevity traits were all high and positive (0.6 to 1.0), as were the phenotypic correlations (0.5 to 0.8). The correlations (Spearman rank) between the sire's estimated breeding values for all the five longevity traits were all significant (P < 0.001) and moderate to strong in both data sets. Estimated breeding value (EBV) correlations between the five longevity traits and traits included in the present Swedish breeding evaluation (Quality Genetics (QG)) were significant in a few cases. Significant and favourable EBV correlations were found between age at first farrowing and both STAY12 and STAY13 (-0.20 and -0.31), as well as between litter weight at 3 weeks and LPL and LTP (0.13 to 0.20). Significant and unfavourable EBV correlations were found between age at 100 kg and STAY12 (0.32), as well as between the exterior conformation score from testing station and PL (-0.20). The level of the estimated heritabilities for longevity indicates that genetic improvement of sow longevity would be possible. However, overall, there was no strong indirect selection for sow longevity with the current Swedish breeding evaluation (QG).
本研究的目的是估计瑞典杂交母猪长寿的遗传参数，以探讨选择该性状的可能性。数据收集自16个商业仔猪生产猪群，涉及2001年1月1日至2004年12月31日期间产仔的杂交（长白猪×约克夏猪）母猪。根据父本品种，将记录有10373头母猪的数据集分为两组，即长白公猪（LS）或约克夏公猪（YS）。使用父本模型，通过生存分析对生产寿命（PL）期间的淘汰风险进行了分析。使用动物模型，通过线性模型分析了从第一胎到第二胎的留种率（STAY12）、从第一胎到第三胎的留种率（STAY13）、生产寿命长度（LPL）和终生产量（LTP）。最差父本之后的母猪被淘汰的风险比最佳父本之后的母猪高1.7倍（LS的后代）和2.4倍（YS的后代）。PL的遗传力估计为0.06（LS）和0.12（YS）。线性长寿性状的遗传力范围为0.03至0.08。四个线性长寿性状之间的遗传相关性均为高度正相关（0.6至1.0），表型相关性也是如此（0.5至0.8）。在两个数据集中，所有五个长寿性状的父本估计育种值之间的相关性（Spearman秩相关）均显著（P < 0.001），且为中度至高度相关。在少数情况下，五个长寿性状与当前瑞典育种评估（优质基因（QG））中包含的性状之间的估计育种值（EBV）相关性显著。在初产年龄与STAY12和STAY13之间发现了显著且有利的EBV相关性（-0.20和-0.31），以及在3周龄时的窝重与LPL和LTP之间发现了显著且有利的EBV相关性（0.13至0.20）。在100千克体重时的年龄与STAY12之间发现了显著且不利的EBV相关性（0.32），以及在测试站的外形评分与PL之间发现了显著且不利的EBV相关性（-0.20）。长寿估计遗传力的水平表明母猪长寿的遗传改良是可能的。然而，总体而言，当前瑞典育种评估（QG）对母猪长寿没有强烈的间接选择作用。
