The breeding of the unrelated animals which may belongs to same breed but having different ancestories; or between different breeds, or between different species, is called out breeding. Outbreeding is of following types:

1. Out - crossing: In this type of breeding, the animals of same breed, but not having common oncestory on either side of their pedigree up to 4 - 6 generations are intercrossed. It has following advantages:Out - crossing is the best breeding method for animals that are below average in milk production and growth rate in beef cattle.
   It overcomes the problem of inbreeding depression.
   
2. Cross - breeding: It involves interbreeding of superior males of one breed with superior females of another breed. It allows the desirable qualities of two different breeds to be combined. This strategy is used either to develop new superior breeds or to improve the local breeds. A number of animal breeds have been developed by this approach.