Ødegård C, Svendsen M, Heringstad B
Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, PO Box 5003, NO-1432 Ås, Norway; Geno Breeding and A. I. Association, PO Box 5003, NO-1432 Ås, Norway.
Geno Breeding and A. I. Association, PO Box 5003, NO-1432 Ås, Norway.
J Dairy Sci. 2014 Jul;97(7):4522-9. doi: 10.3168/jds.2013-7837. Epub 2014 Apr 24.
The aim of this study was to estimate genetic correlations between claw disorders and feet and leg conformation traits in Norwegian Red cows. A total of 188,928 cows with claw health status recorded at claw trimming from 2004 to September 2013 and 210,789 first-lactation cows with feet and leg conformation scores from 2001 to September 2013 were included in the analyses. Traits describing claw health were corkscrew claw, infectious claw disorders (dermatitis, heel horn erosion, and interdigital phlegmon), and laminitis-related claw disorders (sole ulcer, white line disorder, and hemorrhage of sole and white line). The feet and leg conformation traits were rear leg rear view (new and old definition), rear leg side view, foot angle, and hoof quality. Feet and leg conformation traits were scored linearly from 1 to 9, with optimum scores depending on the trait. Claw disorders were defined as binary (0/1) traits for each lactation. Threshold sire models were used to model claw disorders, whereas the feet and leg conformation traits were described by linear sire models. Three multivariate analyses were performed, each including the 5 feet and leg conformation traits and 1 of the 3 claw disorders at a time. Posterior means of heritability of liability of claw disorders ranged from 0.10 to 0.20 and heritabilities of feet and leg conformation traits ranged from 0.04 to 0.11. Posterior standard deviation of heritability was ≤0.01 for all traits. Genetic correlations between claw disorders and feet and leg conformation traits were all low or moderate, except between corkscrew claw and hoof quality (-0.86), which are supposed to measure the same trait. The genetic correlations between rear leg rear view (new) and infectious claw disorders (-0.20) and laminitis-related claw disorders (0.26), and between hoof quality and laminitis-related claw disorders (-0.33) were moderate. Eight of the 15 genetic correlations between claw disorders and feet and leg conformation traits had 0 included in the 95% highest posterior density interval. These results imply that selection for feet and leg conformation is not an efficient approach to genetically improve claw health in Norwegian Red cattle.
本研究的目的是估计挪威红牛爪部疾病与蹄腿形态性状之间的遗传相关性。分析纳入了2004年至2013年9月期间在修蹄时记录了爪部健康状况的188,928头母牛，以及2001年至2013年9月期间有蹄腿形态评分的210,789头头胎泌乳母牛。描述爪部健康的性状有螺旋爪、传染性爪部疾病（皮炎、蹄踵角质侵蚀和趾间蜂窝织炎）以及与蹄叶炎相关的爪部疾病（蹄底溃疡、白线病以及蹄底和白线出血）。蹄腿形态性状包括后腿后视（新定义和旧定义）、后腿侧视、蹄角度和蹄质量。蹄腿形态性状按1至9进行线性评分，最佳分数取决于性状。爪部疾病在每个泌乳期被定义为二元（0/1）性状。采用阈 sire模型对爪部疾病进行建模，而蹄腿形态性状则用线性 sire模型描述。进行了三项多变量分析，每次分析都包括5个蹄腿形态性状和3种爪部疾病中的1种。爪部疾病易感性遗传力的后验均值范围为0.10至0.20，蹄腿形态性状的遗传力范围为0.04至0.11。所有性状遗传力的后验标准差均≤0.01。爪部疾病与蹄腿形态性状之间的遗传相关性均较低或中等，螺旋爪与蹄质量之间的遗传相关性除外（-0.86），这两个性状被认为测量的是同一性状。后腿后视（新定义）与传染性爪部疾病之间的遗传相关性为-0.20，与蹄叶炎相关的爪部疾病之间的遗传相关性为0.26，蹄质量与蹄叶炎相关的爪部疾病之间的遗传相关性为-0.33，这些遗传相关性为中等。爪部疾病与蹄腿形态性状之间的15个遗传相关性中有8个在95%最高后验密度区间内包含0。这些结果表明，选择蹄腿形态并非在遗传上改善挪威红牛爪部健康的有效方法。
