I'm not sure what BSL stands for, but I will look them up. See as a chicken is born with 4000 potential eggs, it is unlikely she could even live long enough to lay them all! But, WOW, thats a lot of eggs she is laying!My BSL hens lay a very large Dark brown terra cotta colored egg, sometimes I even get the speckles............ so you may want to add a couple of them, they do start early and they lay like crazy....... I don't think my one hen with the very huge egg has ever taken a break in a year and a half, makes me sad she is using up all those beautiful eggs so quick because she is such a sweet hen 1 of my favorites.