Pork futures jumped on the open spurred by Wednesday's pork cutout advance, early session cash gains and sharply higher overnight CBOT corn futures.

Also, the central part of the country is in the midst of a deep freeze. That fostered ideas that hog marketings could slow as producers keep animals confined for heating purposes and to protect them from illnesses.

Lean hogs mustered additional upward momentum after February and April moved beyond technical resistance obstacles that set off buy stops and stirred fund buyers.

While February and June maintained most of their initial gains, April pulled back - and at one point slipped into negative territory - because of the contract's bearish premium to CME's hog index.

Also, February/April bull and April/June bear spreads tugged at April and provided February and June backing.

Country hog buyers anticipate steady to firm cash prices for Friday as processors prep for a weekend kill estimated at around 250,000 head.