A pure Green hen and an IB male would produce a 50/50 Spalding. Not sure if this will help but if you want to figure out how much of a percentage the chick will be you take the two percentages of he parents, add them together, and divide by two. That's how registering animals works with other species. For example: you have a mare that is 25% Appaloosa and 75% Quarter Horse. You breed her to a Full Blood (100%) Quarter Horse stud. You will add the Quarter Horse % (175%) then divide by two. You would have a foal that is 87.5% Quarter Horse and 12.5% Appaloosa. Another way is knowing what each ancestor is. In theory if your bird had 15/16 of it's ancestors Green you should have a Spalding that is 94% Green and 6% Blue.
He should stick around if the girls stick around.
Ps: a good green hen will have a uniform barring pattern in the shape of a chevron vs a hen with IB blood in her will have more of a broken TV barring pattern but it can still be hard sometimes.
Edited by barkerg - 4/1/16 at 3:27pm