BOSS contains Vitamin E which plays a role in both the willingness to breed and its success. Vitamin A is also important.
Pelleted feed includes sufficient levels of these vitamins at the time of manufacturing, but if the feed is stored for prolonged periods or in poor storage conditions, these vitamins can be lost.
So there are circumstances where BOSS can make a difference and the same applies to dark leafy plants for Vitamin A. But only if the reluctance to breed is due to vitamin deficiency.