Departamento de Anatomía, Embriología y Genética Animal, Facultad de Veterinaria, Universidad de Zaragoza, E-50013, Spain.
Genetics. 2014 Mar;196(3):643-51. doi: 10.1534/genetics.113.159475. Epub 2014 Jan 10.
This work presents a model for the joint analysis of a binomial and a Gaussian trait using a recursive parametrization that leads to a computationally efficient implementation. The model is illustrated in an analysis of mortality and litter size in two breeds of Danish pigs, Landrace and Yorkshire. Available evidence suggests that mortality of piglets increased partly as a result of successful selection for total number of piglets born. In recent years there has been a need to decrease the incidence of mortality in pig-breeding programs. We report estimates of genetic variation at the level of the logit of the probability of mortality and quantify how it is affected by the size of the litter. Several models for mortality are considered and the best fits are obtained by postulating linear and cubic relationships between the logit of the probability of mortality and litter size, for Landrace and Yorkshire, respectively. An interpretation of how the presence of genetic variation affects the probability of mortality in the population is provided and we discuss and quantify the prospects of selecting for reduced mortality, without affecting litter size.
这项工作提出了一种使用递归参数化联合分析二项式和高斯性状的模型，该模型可实现高效的计算。该模型在对丹麦两个品种的猪（长白猪和约克夏猪）的死亡率和产仔数的分析中进行了说明。现有证据表明，仔猪死亡率的增加部分是由于成功选择了出生仔猪的总数。近年来，人们需要降低养猪计划中的死亡率。我们报告了死亡率概率的对数几率水平的遗传变异的估计值，并量化了其如何受产仔数的影响。分别对长白猪和约克夏猪的死亡率进行了多种模型的考虑，并通过假设死亡率概率的对数几率与产仔数之间存在线性和三次关系，得出了最佳拟合。提供了对遗传变异如何影响群体中死亡率的概率的解释，并且我们讨论并量化了在不影响产仔数的情况下选择降低死亡率的前景。
