A composite breed is a breed that has been developed, and often maintained as a new purebred, by systematically mating at least two component breeds. The goal of a composite breeding program is to blend desired characteristics from the component breeds and retain heterosis in future generations. The greater the genetic diversity between the sire and the dam, the greater the heterosis (hybrid vigor). Breeders can access greater genetic diversity by:
- Selecting across subspecies - The chart below lists various composite breeds, highlights the various component breeds they genetically represent and color codes the component breeds by their subspecies: Taurine (blue), Zebu (green) and Sanga (purple). This is arguable the most cost effective approach.
- Increasing in the number of component breeds - Researchers have estimated the percentage of heterosis that is retained over generations based on the number of component breeds reflected in the composite. For maximum results, no one component breed should be over represented. With each new component breed, you add an additional layer of complexity, time and cost.