**5. Genetic diversity**

Through indiscriminate crossbreeding with exotic breeds, mainly imported from Africa and Europe, it was put at risk the existence and preservation of naturalized breeds that are now important genetic heritage [28]. These animals have characteristics which may be considered useful both from the productive point of view and adaptive such as tolerance or resistance to diseases and parasites and adaptive wide variations related to the availability and quality of food and water. Therefore, the animals best adapted and/or more resistant survived and reproduced to the present day. Thus, the naturalized breeds are a result of the process of natural selection over the years.

Research aimed at the conservation and breeding of naturalized breeds that are important for the selection of animals for the purpose of controlling intersections, avoiding inbreeding, and indiscriminate crossbreeding that thus purebreds are preserved. Therefore, it is necessary to seek a production system that makes evident its potential, so that they are recognized by the creators and that they perceive the possibility of the use of local breeds for higher returns [29].

Studies related to knowledge of adaptive characteristics of different breeds to the environment can sustain production systems in livestock based on adapted breeds, reducing the impact on the environment and receiving better products for consumption.

With recent technological developments, new molecular tools were developed in order to understand the origin and domestication process of domestic species. These tools helped the discovery of evolutionary relationships, taxonomy, and demographics of a wide variety of species, providing important support both in identifying priority areas for conservation programs and in the understanding of genetic diversity in domestic and wild species threat‐ ened with extinction [3].
