Abstract: Chelating resins for use in selectively binding heavy metals, having the structure ##STR1## where Ps represents a poly(divinylbenzene), and R represents an organic radical containing at least one N and/or S atoms but not a C--OH group, that is bound to the S atom. The preparation of these chelating resins is also disclosed.
Abstract: A feeder for poultry comprising a feed tray, a feed supply stack secured on the tray and audio conveying means to facilitate dispersion of feeding behavior enhancing sounds from the stack a feeding period.