This is an introduction to breeding coefficient for the lay breeder as inbreeding is considered unacceptable by the uninformed. This will attempt to inform you to what inbreeding is, how it is used and how to calculate it.

Take the percentage of true relationships and divide by 2 than add the amount from each time that individual is found in the pedigree. This will give you a coefficient that is statistically the percentage of inbreeding(homzygousity).
 

Each parent = 50% divided by 2= 25% breeding coefficient.

Each grandparents = 25% divided by 2=12 1/2% breeding coefficient etc.

(This formula can be carried as far back in a
pedigree as you have pedigree to calculate) 

joe max=25%  mary puppy=37½% inbred coefficient max=12½% lilly=25% susy

This is a father/daughter cross, inbred coefficient is 37 1/2% to Max. He is the only dog that is considered in this demonstration.

INBREEDING:
"The inter-breeding of closely related individuals esp. to preserve and fix desirable characters of and to eliminate unfavorable characters from a stock" Quoted from 'The Merriam Webster Dictionary'

LINE BREEDING:
"The inbreeding of animals descended from an ancestor having some desirable characteristics which it is wished to strengthen and perpetuate" Quoted from 'The New Lexicon Webster's Dictionary'

  As you can see from the dictionary quotes, inbreeding and line breeding are actually the same thing. The use of ancestors to perpetuate or eliminate characteristics. Out breeding is used to gain characteristics your stock lacks or to hide detrimental characteristics your stock has.

We will, also, attempt to explain out-breeding, what it is, how it is used and how to use it

INBREEDING (LINE BREEDING):
"The inter-breeding of closely related individuals esp. to preserve and fix desirable characters of and to eliminate unfavorable characters from a stock"

Is the use of related individuals in a breeding program when intensely used such as father/daughter, mother/son, brother/sister, grandfather/granddaughter, grandmother/grandson, this is called inbreeding.

Inbreeding is used to establish type, I.E., when an exemplary individual comes close to your 'ideal' of the perfect cocker you might inbred to that cocker to create puppies with similar type to use in your future breeding efforts.

You might use inbreeding to establish a specific color or coat pattern such as breeding a non brown bitch back to her brown father to produce brown puppies.

You can, also, use inbreeding to check your stock for detrimental recessive genes:
Although this will produce a higher than average amount of  deleterious effects in resulting offspring it is the responsible breeders obligation to ferret out these detrimental genes.(and be prepared to care for these individual animals)

The difference between the use of the terms inbreeding and line breeding is that inbreeding is usually thought of as coming from one side of the pedigree, but line breeding comes from both sides such as both parents having the same dog in their background, in reality they are the same. They are the accumulation of homozygous genes. The only, per se, thing to be concerned with in inbreeding is loss of vigor.

In other domestic livestock, a breeding coefficient of 37% is considered normal in the breed as a whole. So one back cross to a parent would be no more inbred than the breed as a whole.

Inbreeding can be used for many purposes, specific traits such as color, length of ears, size of feet and bone, neck, etc, any good reason. But inbreeding just because they are handy is never a reason to inbred. This will bring down your quality and stamp it on succeeding generations.

Inbreeding can be used to bring up the quality of your breeding stock but line breeding will maintain it. This means a closed breeding group all future breeding animals are selected from within a related group.

All of these methods of breeding should be done with caution and careful selection of future breeding stock.

OUT-CROSSING:
The interbreeding of different breeds (cockapoo) or species (mule) of animals, IE. ', as you can see this term is of no use to the serious cocker breeder.(So the next time you hear someone mention a complete out-cross ask them whether they bred to a poodle or a jack.)
Out breeding is the mating of as unrelated individuals as is possible within the same breed.

Out breeding is used to bring in traits to your gene pool to enhance what you already have. Out breeding is, also, used to mask deleterious recessive traits in you breeding stock, such as eye and hip problems.

Out breeding is used when you need to gain specific traits in your breeding stock and you can not find it in related stock or your closed breeding program is too small in numbers and you find yourself in the situation of loss of vitality or constant small litter size.