Ah! The powder will hit 15 animals within the yard. How many butterflies do you have? If it's less than 15 and the chickens are not dropping grain then it's a bug.
Hell, I just went to my Piggy room (picture here) and even they dropped meat! Why does everyone drop things besides the chickens! (especially when I stood right beside them to use the powder!)
I fired off a dose in a narrow gap between twenty butterflies and about the same amount of piggies, startlingly crappy might be a better description of the yield, about comparable to fifteen seconds 'hard' work harvesting the normal way, what's the point and what yield is the lesser product. Hardly worth the effort of using it let alone making the stuff.