[knightquest]

I can understand line breeding in farm and working animals. If you have a sheep for instance that produces perfect wool then it makes sense to use that sheep to produce young. The same with a working dog. If they are top notch at their given activity then they should be used.

My problem is that when you restrict any gene pool which is what you do with line and in breeding, then you increase the bad news as well as the good. It seems to me that the problems may not show themselves for five, ten or fifteen generations and the benefits show themselves more quickly.

As I have a background in dogs, they bother me most. To breed for looks is flawed. Dogs should be bred for longevity, health and temperament. All dogs should have a working title before they are shown and by the way, the handlers and owners should always be made to wear the same clothes and a clowns mask so that the judge doesn't know who they are. But that's another subject 

When we line breed we play god. In nature, the strongest and fittest get to breed, not the ones with what we perceive to have the nicest eyes for instance.

Remember that bloke who wanted humans to all look the same? His name was Hitler. Look where it got him!

Personally, I think that it's better for animals to be fit for purpose and look different than to have a group of 'clones'

Rant over,

Ian

[Hardfeather]

Knightquest
I take your point about the strongest and the fittest getting to breed. However, a good stockman will always ensure that he is breeding from the best available to him and, if he is ruthless in his disposal (by culling or distribution) of his less than acceptable products, he should always have first class individuals from which to choose his brood stock.

The problems start when indiscriminate or ill-informed breeders get carried away with creating fads rather than useful qualities and properties in their stock.

Gene pools can be naturally restricted owing to geographical influence; for example, where populations of wild animals are isolated from others of their species. This has happened in parts of Africa where some prides of lions are  showing signs of hereditary weaknesses, and are desperately in need of an outcross.

Outcrossing is one of the problems encountered in poultry breeding where a strain of birds has been line-bred for a long period. There comes a time, when the stock is beginning to degenerate in some way(s) owing to the length of time without an outcross. The sourcing of the outcross is, however, dependant on finding an individual which is as good as the line-bred stock, and which will compliment that stock.

Crossing out into related stock is one of the best ways to lessen the possible detrimental impact of an outcross. This is why some advocates of line-breeding will always have two or three (preferably) similar populations of basically related stock; that is, relatives with common ancestors, from which the breeder can draw an individual which has some genes in common with the stock to be outcrossed. By that means, an outcross can be used to infuse vigour and strengthen characteristics in a strain.

Playing God is, unfortunately, practiced in many breeding circles these days, not least in domestic pets. Playing God is, however, in some breeding, essential if the world is to be fed.

[doganjo]

Interbreeding is the opposite to inbreeding. It is the breeding of two totally unrelated animals. Unfortunately as it sounds like inbreeding it commonly used when the user means inbreeding
Rose

In dogs, which is the only animal I breed other than a few dooks 'n' chooks, that would be termed outcrossing.  I might say also that I breed for temperament, working ability,as well as looks - my kennel motto is "Goodlooking AND Intelligent"

[knightquest]

The problems start when indiscriminate or ill-informed breeders get carried away with creating fads rather than useful qualities and properties in their stock.

Gene pools can be naturally restricted owing to geographical influence; for example, where populations of wild animals are isolated from others of their species. This has happened in parts of Africa where some prides of lions are  showing signs of hereditary weaknesses, and are desperately in need of an outcross.

Playing God is, unfortunately, practiced in many breeding circles these days, not least in domestic pets. Playing God is, however, in some breeding, essential if the world is to be fed.

AengusOg,

I agree with what you say. I have selected the points above that I agree most with especially the ill informed breeders and fads bit. 
The African lions illustrate the problem perfectly.
My problem is mostly with dog breeders and their fads. Feeding the world is obviously important and I have to admit that I don't know enough about genetics to have a better solution.

Ian