My smart phone did not post what I thought I typed. Here father daughter works well . Mother son has not. Same level of coefficient.
That being said , when I worked in aniaml research with some of the best genticists in the world, both at the epigentic level and the molecular genetics level, none were concerned with any matings we did , except full sibs. That was done only as a back up plan to preserve genetic lines. Since our cell lines were proprietary and g8 to g 10 cloned lines, it became an issue of inbreeding regression. We had 1 cell line that worked well in our program, but the more intensly that line was inbred, them more defects came out. The full sib mating was anaylized for 2 years before being attempted, and worked as well as any. But was the only mating they were concerned with ,that can bring lethal gene defects out , even in what is considered a clean pedigree. This company help write the computer program that finishing mapping the bovine genome. Any thing published before about 10 years ago in genetics , was largely based on conjecture and mathematical equations. No one really knew all the possible outcomes, as the possibilities of genes stacking differently are in the 10s of thousands. Some the previous calculations were based on mathematical equaitons of conjecture and probibilities. After the computer programs and actual computer capabilities were big enough to tackle the task, the outcomes are different than previously thought.
It was easier to send men to the moon and likely mars, that project the outcomes of some of the genetics . Simply put, negative associations from environment can mutate genes as they are assembled in the formation of the egg. The full sib mating provides the best foundation to express the mutations.
That being said, in my commercial hair flock last year, I did do a full brother sister mating. The resulting ewe lamb is easily the best of the bunch. She is batsh-t crazy and will shake violenty if pressured in pen
Her background has at least 5 generations of 100 percent unrelated in any way . Clay Center has carefully started that project with 38 ( i think.may have been 18)parent lines that are unrelated in any way.
But breeding full sibs that have common ansestors is much more risky.
Hope my phone does not " mutate" this post.
As stated , it would be done as last resort and many preservation lines do this. However most preservation lines are more primitive to begin with.
That was discussed at lenght in the above program. In nature, you have selective and Darwin working. Weakings are naturally culled
When man intervenes , weaklings are saved and generally propegated as now there is emotional attachment.
We had a lot of female caregivers for our clones , and mostly scientific males types that enfforced a very strict culling strategy.
