The practice of mating closely-related animals is called

The practice of mating closely-related animals is called inbreeding. Inbreeding is the process of mating closely-related individuals, such as siblings or parents and offspring, within the same family or line. The main objective of inbreeding is to enhance the expression of desirable traits or to fix a specific genetic trait in a population. However, inbreeding can also lead to the expression of harmful recessive genes, which can result in reduced performance and fitness of the offspring.