Apparatus for engaging a filler/product pump that include: (a) a horn having a length, an outer surface and an internal product channel extending therethrough; (b) a forming collar in communication with the horn, wherein, in operation, the forming collar is configured to cooperate with the horn to direct planar casing material to take on a generally tubular shape over an outer surface of the horn while product travels through the internal channel; (c) a netting chute sized and configured to receive a portion of the horn therein, the netting chute configured to hold a sleeve of elastic netting material thereon; and (d) an automated derucker operatively associated with the netting chute whereby the derucker is configured to automatically travel through a derucker stroke cycle comprising upstream and downstream locations to pull segments of netting material toward a downstream end portion of the netting chute while product is pumped out of the horn.