ABSTRACT

We estimated the effect of inbreeding on racing performance in the Standardbred trotter. A random sample of 1,217 horses with organized pedigree was utilized to calculate individual proportions of French and American ancestry and their heterozygosity and inbreeding coefficients. Average earnings per start for the 807 raced horses summarized between three and five years of age were analysed, after first applying a fourth-root transformation followed by standard-normalization within their birth-year group (1988 and 2006/2007). The resulting variable was analysed using a linear model with fixed effects of sex, additive breed effect and a regression on the squared inbreeding coefficient. The model was expanded with a fixed effect of birth-year and a random effect of animal. In both models, the regression coefficient for the squared inbreeding coefficient was found negative (P < 0.04). Breed effect was not significant. Heritability was estimated as 0.227 ± 0.106.

摘要

我们估计了近亲繁殖对标准猪蹄赛车性能的影响。使用1,217匹有组织血统的马的随机样本来计算法国和美国血统的各个比例及其杂合性和近交系数。在首先对四岁儿童进行出生年龄组（1988年和2006/2007年）的第四次根转换，然后进行标准归一化之后，分析了三到五岁之间的807匹赛马的平均每次启动收入。使用线性模型对结果变量进行分析，该模型具有固定的性别效应，加性繁殖效应以及对近交系数平方的回归。该模型在出生年份的固定影响和动物的随机影响下进行了扩展。在两个模型中P  <0.04）。繁殖效果不显着。遗传力估计为0.227±0.106。