HL,
the white comes from a recessive gene,both the lab and retriver have a white recessive and it was able to express itself in the hybred!
If you bred your dog back to a "black" lab or "golden" retriver chances are you wouldnt see another "white" in the litter. Your dog would be considered a phenotype!
These "phenoes" are usually very sound and healthy animals,however their pups may suffer from all sorts of nasty things that normally wouldnt be seen in a "pure" strain.
They are important as all the breeds were developed from this type of breeding but it can involve plenty of trial and error and many pups that must be put down!
