inbreeding how to, how not to?

[Jossi]

As you probably know I have bought 4 blue back goulds.They wont be up for breeding this year, but I was thinking nex fall/winter, they will then be 1,5 years old. They are all siblings so they wont be breed with each other, but with unrelated normals.

But since the blue are hard to find around here and I intend on selling the offspring witch will be split blue, I guess that people might be interested in getting both a female and a male split to blue for the chanse of blue offspring.
Is it safe to breed offspring that are cousins (is this the right term in english?) What I mean is for instans two sisters that breed with two different males and their offspring is then put together... I hope you get what I mean

I am going to try my best to find two split blue that I can use to safely produce blue backs... but if I have no luck?

I know that the blue I just got have parents that are totaly unrelated.

Im new to this genetic stuff and I can assure you that I really dont want to inbreed if it is posible as I know that it weakens the blood line and I really dont want that. It has never been a problem before since I up to now only breed the normals that are easier to find, but now that this colour is a bit hard to get hold off, I just want to know what my options are I would really love to be able to produce some blue offspring in the future.

If its not to recommend I will just have to sit here and watch my little beauties and be happy that I got some myself

Thanks

[nixity]

I would suggest out crossing as much as possible.
It will take longer this way, but you'll get much healthier babies in the long run. The problem with line breeding is that most people are selecting for not just one, but multiple desirable traits, and they will line breed to try to "seal" those traits in the offspring.
In this case you're only selecting for color, so while you may end up with blue birds, you may also end up with small, wiry, snaky birds, too. If you're going to go the route of line breeding (cousin to cousin) make sure you select the absolute best birds and don't do it just to get the blues or to make the sale, you know?

Also, if blues are so hard to find, how do you know for sure the blues you got came from unrelated pairings?

This is something to consider because if they are at all possibly already inbred themselves, inbreeding again at any level could have disastrous results.

[Jossi]

I cant be sertain that they are not related, since I didnt breed them my self, but I do trust the breeder. Acording to him one of the parents are imported from Holland (another country).

I dont want to do this if I can get my hands on some split blue from another breeder, but it took me about 1,5 years to get the blue I have.

I do have some time, since Im not breeding them for another year, and their offspring wont be breed until the year after that... I just want to be sure about how to do it when the time is right and I want some options if I dont have any luck with finding anything.

Ill take everything you write in consideration and no doubt about the fact that I will only use the best birds for breeding, witch is what I do with all of my birds, rare or not