Buitenhuis A J, Lund M S, Thomasen J R, Thomsen B, Nielsen V Hunnicke, Bendixen C, Guldbrandtsen B
Danish Institute of Agricultural Sciences, Department of Genetics and Biotechnology, PO Box 50, 8830 Tjele, Denmark.
J Dairy Sci. 2007 Jan;90(1):472-81. doi: 10.3168/jds.S0022-0302(07)72649-8.
Lameness is an important factor for culling animals. Strong legs and feet improve herd life of dairy cows. Therefore, many countries include leg and feet conformation traits in their breeding programs, often as early predictors of longevity. However, few countries directly measure lameness related traits to include these in a breeding program. Lameness indices in 3 different lactations and 5 leg conformation traits (rear legs side view, rear legs rear view, hock quality, bone quality, and foot angle) were measured on granddaughters of 19 Danish Holstein grandsires with 33 to 105 sons. A genome scan was performed to detect quantitative trait loci (QTL) based on the 29 autosomes using microsatellite markers. Data were analyzed across and within families for QTL affecting lameness and leg conformation traits. A regression method and a variance component method were used for QTL detection. Two QTL each for lameness in the first [Bos taurus autosome (BTA); BTA5, BTA26] and second (BTA19, BTA22) lactations were detected. For the 5 different leg conformation traits, 7 chromosome-wise significant QTL were detected across families for rear legs side view, 5 for rear legs rear view, 4 for hock quality, 4 for bone quality, and 1 for foot angle. For those chromosomes where a QTL associated with 2 different traits was detected (BTA1, BTA11, BTA15, BTA26, and BTA27), a multitrait-1-QTL model and a multitrait-2-QTL model were performed to characterize these QTL as single QTL with pleiotropic effects or distinct QTL.
跛足是淘汰动物的一个重要因素。强壮的腿脚能提高奶牛的群体寿命。因此，许多国家在其育种计划中纳入了腿部和足部形态特征，通常将其作为长寿的早期预测指标。然而，很少有国家直接测量与跛足相关的性状并将其纳入育种计划。对19头丹麦荷斯坦种公牛的孙女进行了测量，这些孙女有33至105个儿子，测量了3个不同泌乳期的跛足指数和5个腿部形态特征（后腿侧视图、后腿后视图、跗关节质量、骨骼质量和蹄角度）。使用微卫星标记基于29条常染色体进行全基因组扫描以检测数量性状位点（QTL）。对影响跛足和腿部形态特征的QTL进行了家系间和家系内数据分析。采用回归法和方差成分法进行QTL检测。在第一个泌乳期 [牛常染色体（BTA）；BTA5、BTA26] 和第二个泌乳期（BTA19、BTA22）各检测到两个跛足QTL。对于5个不同的腿部形态特征，在家系间检测到7个染色体水平显著的QTL与后腿侧视图相关，5个与后腿后视图相关，4个与跗关节质量相关，4个与骨骼质量相关，1个与蹄角度相关。对于检测到与2个不同性状相关的QTL的那些染色体（BTA1、BTA11、BTA15、BTA26和BTA27），采用多性状-1-QTL模型和多性状-2-QTL模型将这些QTL表征为具有多效性的单个QTL或不同的QTL。
