U.S. lean hog futures closed mixed, as the nearby contract got support from hot weather that has caused lower hog weights.

August lean hogs closed up 1.125 cents, or 1.1%, to $1.016 a pound. Oct lean hogs close down 0.325 cents to 91.375 cents.

USDA reported average hog weights in Iowa/southern Minnesota for last week at 263.7 pounds, down 2.9 pounds from the previous week and 4.7 pounds below a year ago. The latest figure was also the lowest since early July 2009.

Meanwhile, the USDA's pork carcass composite value, a measure of wholesale prices, on Tuesday rose $1.03 to $101.31 a hundred pounds, a new all-time high.

Strong export sales amid growing world demand, seasonally smaller hog supplies and high feed costs are contributing to rising wholesale and retail pork prices, analysts say. Wholesale pork prices are up nearly 17% from a year ago.

Futures gains Wednesday were limited by the broader concerns about the economy as the prospect of a U.S. default on its debt grows.

Cash hog prices were reported mostly steady. Tightened supplies of slaughter-ready animals and lighter average weights are helping support cash prices as processors compete for the available animals.

Four pork plants are scheduled to be closed Monday, three of them for a floater holiday.

Some livestock dealers and market managers predict that cash hog prices could remain generally steady through the balance of this week and into next week despite the plant closures Monday since supplies are snug.

The terminal markets traded steady to as much as $3 higher with top prices from $65 to $74 a hundred pounds on a live basis.