Principles of Genetics and Breeding

13.1.12.3. Factorial Mating

Factorial mating also involves mating one male with one female but may require spawning an individual of the least numerous sex with multiple is most useful when the number and sex of broodfish is limiting because it results in the use of all available broodfish and increases the diversity of alleles passed to the next generation.

Factorial mating is a more complex, labour-intensive, controlled breeding strategy than the simple one-on-one, and its execution is enhanced by gamete extension and subdivision methods.

For example, when females are the limiting sex, then an egg lot from a female is partitioned or subdivided into aliquots, each of which is fertilized by a different male until all males are used.