Split refers to having only one copy of a recessive gene. There is no obvious indication that the gene is present (because it is recessive)--you know it is because of your breeding.
A black split to lavender is genetically (Lav,lav). A regular black would be (Lav,Lav), and if the split had had a 2nd copy of lav (lav,lav) it would have been lavender rather than black.
Any creature can only pass the genes it possesses to its offspring.
A lavender bird (lav,lav) will always pass lav to its offspring.
A split can pass either of the two alleles (Lav & lav) that it carries; some will receive Lav and others lav. Statistically that should be about 50/50.
Somewhere there's a website that gives an example (including simple drawings) of a person wearing shorts and long pants. When he's wearing the long pants you can't see the shorts hidden underneath, but if he only has on shorts you can see them. Of course that requires the leap of "why the heck is someone wearing two sets of pants?!"
Sonoran silkies, I have another way of explaining what you said in a simpler way, using letters not words as i find it easier. if B=black (dominant) and b=lavender(recesive), then the split blacks you are refering to are Bb (heterozygous). then homozygous black (BB) and lavender (bb).
will the OP do a test cross with the black/split black pullets?
Absolutely no! Recessive and dominant relate to the alleles of an individual gene, NOT to the relationship between different genes!!! And that is what the relationship between black and lavender is. A not-lavender bird is not necessarily black, but black has fewer genes that react with lavender to create other patterns and varieties.
Black is a specific gene: the E allele, and there are a number of different E alleles. Most of them can be used to create a completely black chicken with the addition of helper genes.
Lavender is the lav gene, and there are two alleles: lav for lavender and Lav for not-lavender.
Please don't use made up letters as many of them are actually used to refer to specific genes and that becomes confusing. B is the barring gene. It you want to use words, use "lavender" and "not-lavender"
Quote:
All black/splitblack pullets will be paired with the lavender cockeral. What will be will be. Once lavendar pullets are established then all black/splitblack pullets will be removed.