sport is a color variance in blue bird breeding, commonly called splash
these come from say a blue millie fluer, you'll get 2 blue millie fluer, 1 millie fluer, and 1 sport millie fluer. The sport has not meaning in white birds
There are dominate and recessive white
Dominate will breed white always, recessive white will not unless bred to another white bird.
Dominate white is what is used in genetic work to make your white patternted birds
examples
red plye is a bb red bred to a dominate white
goldneck, a millie fluer bred to dom white
buff laced, a gold laced bred to dominate white.
Basically, it works like blue does, in a way, if you cross bred a dominate white to a bird of color, the black feathers of the colored bird will be replaced by white ones, and the remainly feathers will be diluted to a paler version
As for which are which, I'm not sure, most arent, most are reccessive. If it is a breed with the above colors listed in it, then you can bet dominate whites exist in that breed
There are some genetic masters on here that I am sure will be along soon and can maybe shed more light on which breeds commonly have them in dominate white.
