The reason most people experience losses with new rare breeds is often because of a limited gene pool. Greenfire farm has started getting smart when importing after this repeated problem their customers experience by importing unrelated birds and then later importing another group. Unfortunately they didn't have that practice when they imported Bredas. So getting different genetic is kind of a luck of the draw.
Also when getting a new breed it's really important to get your birds from different breeders. I got my bredas as eggs from different suppliers but it is still a very limited gene pool.
I have a different opinion on gene pools.
In third world counties native breeds might only lay 80 eggs a year and might only reach mature weights of 4 lbs. Humanitarian groups started to import commercial breeds to these areas to improve their quality of life. They might import leghorns that produce 300 eggs a year or Brahma meat birds that average 14 lbs mature rate, but what they found is that these imported breeds would fail to thrive in the new area. They had to change the way they were doing things. I read a manual written by one of these group that had a recommend breeding plan that rather than trying to breed an imported Leghorn to another imported leghorn to produce pure leghorns they would cross the imported stock with the native stock and grade the native stock over to the Leghorn standard.
The native stock had lived in the areas for decades if not centuries and had adapted to where they could withstand all the conditions in the area. The bacterial found in the soil in one part of the word will be very different that what is found in a different part of the world. The breeds that had developed in the area have the genetic make up suited for the area. The imported breed might not. If a wide gene pool were imported then there would always be a portion of it that was suited for the new conditions (bacteria, diet, pathogens, climate, etc.). For example, if fowl pox went through the flock a wide gene pool would surly have some birds survive (but a narrow gene pool might not) because their genetic make up would allow them to be more resistant to the particular strain of fowl pox than others. When the survivers are breed together they pass of their genetic make up to their offspring and when the next generation gets hit by the same strain of Fowl pox that is unique to that area a higher percentage of the flock survives. They breed again the flock continues to adapt. Breeding the native birds that already had adaptations to pass on to offspring was more effective at establishing commercial birds in the third world counties than a large scale breeding project that might be logistically impossible to do.
I had a man in Canada tell me about one of the large breeding projects they did. They imported Light Sussex from the UK to a research station. In doing so they sought out a good cross section of the gene pool by getting stock from several unrelated blood lines. They then put all the imported stock in a single flock and grew it to 500-600 birds. As you can imagine they get a lot of cold weather in Canada in the winter and have other notable difference in climate from the UK (i.e. the feed wheat to their chickens in the UK but they feed Corn to their chickens in Canada, etc.). They let the flock "settle" for several years to allow genes to mix and for the ones best suited for the climate in Canada to rise to the top. They did this but not culling for the first five years. They kept a cockerel for about every 3 hens and let natural selection take its course. Line breeding or culling could block certain genes from rising in the gene pool. They reported that the birds became flighty, their eggs got really small, egg production was really low, etc. After they flock had mixed for 5 years they started line breeding and got cockerel 2 pound over the breed standard in just three years and reported that other utilities had similar success at being regained.
The man in Canada said the problem with Green Fire farm's method was not the number of birds or number of blood lines they were importing but the way they were being breed. They sell stock right away with out mixing the blood in large flocks. They mix what they are selling the best that they can and hope that some back yard breeder will do the flock of 500 hundred that isn't culled for several years thing (that ain't going to happen in backyard flocks). I say grow out as many as you can. I am a backyard breeder and limited in what I can do. My limit is 100 birds a year. I focus on vigor in my breeding. If someone has a respiratory illness they are culled, if someone holds their wings low they get culled. If they are not putting on enough weight they are culled, if they walk with stilty legs they get culled, if they sit in the hen house all day and don't forage they get culled. I have to grow out 100 so that I can get 2-3 good cockerels 4-6 good pullets. I never seem to get as good of birds as I want and always resolve to hatch a bigger group the next year.
To much red in the lobe.
