Why Is Quantitative Genetic Analysis Important

Why is quantitative genetics important for animal breeding and production? (7)
Quantitative genetics is defined as the study of effects that heredity and environment have on traits that can be quantitatively measured, such as size. Quantitative genetic analysis is performed on traits showing a continuous range of values, such as height and weight. However, traits displaying a discrete number of values (such as number of offspring) and even binary traits (such as disease presence or absence) are all amenable to quantitative genetic analysis. The genetic architecture of a complex trait consists of all the genetic and environmental factors that affect the trait, along with the magnitude of their individual effects and interaction effects among the factors. The quantitative genetics approach has diverse applications. It is fundamental to an understanding of the variation and co-variation among relatives in natural and managed populations, of the dynamics of evolutionary change, and of the methods for animal improvement and alleviation

However, a trait is expressed not just based on genes but also environmental factors. The effect of the environment can be manipulated by breeders and is thus called management, traits with low heritability need to be more carefully managed to reduce the non-genetic or environmental differences. Traits related to reproduction and fitness tend to be lowly heritable and therefore the environmental conditions should be regulated for optimum selection. Management refers to the non-genetic factors that affect phenotype in animals. This includes housing, nutrition and controlling climate. The relationship between heritability and management in breeding is important as we utilize this symbiosis by calculating genetic evaluations, predicting response to selection, and help show the efficiency of improving traits through either management or through