Chicago Mercantile Exchange (CME) live cattle futures firmed on Thursday, supported by concerns about heat stress in the US Plains, as well as optimism in the cash cattle market, Reuters reported, citing analysts.

"The cash outlook seems pretty firm," said Doug Houghton, technical analyst at Brock Capital Management. " I think there's some support maybe from the hot weather in the plains too."

Most-active October live cattle added 2.050 cents to 180.725 cents per pound. October feeder cattle firmed 2.375 cents to 253.250 cents per pound.

Cattle slaughter increased versus a day earlier to 124,000 head, matching the same period last year, according to the US Department of Agriculture (USDA).

Boxed beef prices ended higher, with choice cuts gaining 58 cents to $317.63 per hundredweight (cwt), while select cuts added 32 to $291.91 per cwt., the USDA said.

CME lean hog futures also climbed on strength in pork prices, despite seasonal pressure.

"A lot of it's because just the futures are so far discount to cash," said Houghton. "The cutout value was up a fair amount."

The most-active October futures LHV3 added 1.925 cents to 80.475 cents per pound.

Wholesale pork carcass cutout added $4.13 to $104.92 per cwt.

Daily hog slaughter of 471,000 head was down from 480,000 the same period last year, according to the U.S. Department of Agriculture.

The CME's Lean Hog Index .IHX, a two-day weighted average of cash prices, last dipped to 97.37 cents per pound, its lowest since July 6.