RCT QUARTERLY 2nd Edition | Page 12

Terms you will hear talked about in the dog world.

OUTCROSSING

LINE BREEDING

The distinction between

Line-Breeding and In-Breeding

all depends on who you talk to! 

Some breeders tend to refer to

In-Bred litters as Line-Bred.  Given the human

taboo's about In-Breeding, there is a tendency to

shy away from the term "In-Bred", particularly when talking to

those unfamiliar with the topic.

We must remember that human values regarding In-Breeding do

not apply universally in the animal kingdom.  Our values are based

on our own social structures and in family dynamics.  In the animal

kingdom it is not at all uncommon for father-daughter and mother-son

matings to occur.  In a wild dog pack, commonly the alpha (most dominant)

dog will mate the bitches.  Sometimes only the alpha bitch will rear

puppies - killing off any puppies that might come from a lower ranking female.

 However, if the alpha bitch dies and the alpha dog remains, he will quite naturally

mate with females in the pack - most likely many of these are his daughters.

This process has occurred throughout the ages, and yet we still have the canine species! 

So obviously, it is not a recipe for disaster, but it does have it's risks.  The most obvious danger

in In-Breeding is the condensation of undesired genes.  These may be carried recessively

(i.e. in the genetic material or "genotype", but masked by a more dominant gene so the trait is not seen in the

animal - or "phenotype").  Clearly, if an animal carries an undesired recessive trait, then there is a chance (mostly around 50%)

that a daughter might carry the same trait.  Thus any progeny from the two will have a probability (around 25%) of exhibiting the undesired trait.  On the surface of it "outcrossing", i.e. breeding two unrelated animals, may seem safer.  But, there is still a chance that they may both happen to carry the same undesired trait and so the progeny are similarly affected.

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