Well, I grew up in North Texas "back when". We had lots of cotton, and many folks used cotton seed hulls - or burrs - same thing/different word, as supplemental winter feed. At the time they were plentiful and cheap. The hulls or burrs were mixed with something, usually in liquid form, to add palatability and nutritional value, both of which are lacking in burrs, and fed out in troughs. I can't remember problems with lump jaw or anything like that, but then I can't remember much anything else, either. I've not heard the term "cotton trash" before, but if it refers to a product that contains not only the hulls but the pieces of cotton stalks, leaves and bolls that are left over from the ginning process, that could be some fairly sorry stuff, I guess.