Give examples of interspecific hybridization in animal breeding. Explain why crossbreeding in this case is limited to the F1 generation.

distant hybridization is used much less frequently in animal breeding than in plant breeding, since the offspring obtained from crossing animals of different species is sterile. But interspecific hybrids may possess economically valuable traits. For example, from ancient times in livestock production a hybrid of a horse (mare) with a donkey (male) – a mule is obtained.