(adversary proceeding within Chapter 7 bankruptcy; ag supply dealers’ liens determined to have super priority status over plaintiff’s liens to extent the feed supplied to hogs shipped to Iowa to the extent the acquisition value of the livestock was exceeded by the livestock’s value at the time the lien attached; dealers brought summary judgment motions claiming sales price of hogs exceeded acquisition costs which were based on per hog grower payments, so entire amount of liens should be paid; court held state court decisions did not provide guidance on calculating difference between acquisition price and livestock’s value, so summary judgment denied).