Son of Butch":1a9gjg1l said:
Rule of thumb: 8 different individuals as great grandparents = outcross pedigree
And yet if any or all of the 8 "different" grandparents are full (or 3/4, half or even 1/4) siblings,
the inbreeding coefficients will be far higher than 3.125%.
Yes they certainly can be, hence "Rule of Thumb" and not written in stone.
An example would be the Holstein breed average coefficient is approximately 6.25% = first cousins
The great Holstein show sire Goldwyn really sires beautiful daughters and stamps his pattern on them.
His sire James coefficient is 3.67% and his dam Baler Twine is 9.74%
But because of the intense linebreeding of both Grand and Aerostar in his pedigree
Goldwyn's inbreeding coefficient is 15.7%
All pure breeds have to have the same ancestors in common at some point to make them a breed.
The current angus genetic pool is more diverse than the holstein breed and many others.
In angus 8 different great grandparents in most all cases will not be a common inbreeding coefficient problem
IMO the direct correlation of inbreeding coefficient % and stillbirth % is the number #1 reason to outcross