U.S. lean hog futures were mixed Tuesday as weaker cash prices for animals weighed on sooner-expiring contracts and corn prices supported futures for winter and spring.

The October hog contract fell 0.57 cent, or 0.6%, to 89.4 cents a pound in trading at the Chicago Mercantile Exchange. December hogs fell 0.12 cent, or 0.2%, to 85.67 cents a pound. The February contract was up 0.35 cent, or 0.4%, to 88.05 cents a pound.

October hog futures felt pressure after cash prices weakened during the session. Traders are carefully watching cash prices since October futures, which expire Oct. 14, are currently trading at a roughly 17-cent discount to cash prices. Futures and cash prices converge as a contract nears expiration.

Despite that steep discount, October futures are nonetheless trading nearly 10 cents above the highest price at which October has ever expired. Some investors are betting cash prices will remain at historically high levels, while others say recent record pork prices will fade from view quickly as hog producers in the Northern Hemisphere, including China, boost production in autumn.

Pork prices and hog futures rallied to records in July as China worked to boost its pork supplies and a summer heat wave in the Midwest led to slower weight gains in animals, which in turn tightened supplies.

Corn futures for December rose 1% to $7.27 1/2 a bushel at the Chicago Board of Trade. A rise in corn prices can support livestock futures since producers will try to recoup higher feed costs, which can also pressure producers to shrink herds. Some traders dispute the connection and argue supplies of fresh meat, rather than a producer's costs, are the determining factor of prices.

Cash hog prices were reported mostly steady to weaker on expectations of gradually increasing supplies through late summer and fall. Slaughter estimates for Monday and Tuesday were each 413,000 head, the largest first two-day total in a non-holiday week since late March.

Terminal markets traded mostly steady to $1 per hundredweight lower on a live basis with top prices from $69.50 to $72 per hundredweight on a live basis.

The USDA's pork carcass composite value, a measure of wholesale prices, on Monday fell 40 cents to $109.45 a hundred pounds.