Pros and Cons of:
Inbreeding (mating of closely related individuals)
Pro
- Produces uniform or predictable offspring.
- Hidden (recessive) genes show up and can be eliminated.
- Individuals will “breed true” and are “pure”.
- Doubles up the good genes
- Eliminates unwanted traits.
- Con
- Doubles up on faults and weakness
- Progressive loss of vigor and immune response
- Increased reproductive failures, fewer offspring
- Emphasis on appearance means accidental loss of the good genes for other attributes
- Genetically impoverished individuals
Line-Breeding (mating of less closely related individuals)
Pro
Avoids inbreeding very closely related Roller pigeons, but the Rollers are still pure
- Produces uniform or predictable offspring
- Slows genetic impoverishment.
Con
- Requires excellent high value breeders
- Does not halt genetic impoverishment, just slows it down
Outcrossing (mating unrelated individuals within the same breed)
Pro
- Brings in new qualities or reintroduces lost qualities
- Increases vigor
- Still pure Rollers
Con
- Less consistency and predictability of offspring
- May have to breed out unwanted genes accidently introduced.
- May be difficult to find individuals which are true outcrosses
- May take years to get consistent offspring
- Produces many variants not suitable for use in the breeding program.