The chi-square and Wishart distributions play an important role in animal breeding applications, especially in the estima-tion of variance components using Bayesian methods. These two distributions are so related that one can easily be derived from the other. In other words, the chi-square distribution is a particular case of the Wishart distribution or the Wishart distribution is a mul-tivariate generalization of the chi-square distribution. This article provides a simple mathematical basis of the above-mentioned dis-tributions; it shows how one is derived from the other and in what from they are used in animal breeding applications.

The chi-square and Wishart distributions play an important role in animal breeding applications, especially in the estima-tion of variance components using Bayesian methods. These two distributions are so related that one can easily be derived from the other. In other words, the chi-square distribution is a particular case of the Wishart distribution or the Wishart distribution is a mul-tivariate generalization of the chi-square distribution. This article provides a simple mathematical basis of the above-mentioned dis-tributions; it shows how one is derived from the other and in what from they are used in animal breeding applications.