CHICAGO, Jan 30 (Reuters) - Lean hog futures on Chicago Mercantile Exchange rose for a sixth straight session on Tuesday, notching a four-month high, as cash hog prices firmed, traders said.

CME April hogs settled up 1.475 cents at 84.900 cents per pound after rising to 85.925 cents, the contract's highest since Sept. 20.

The CME's Lean Hog Index, a two-day weighted average of cash prices, rose to 70.60 cents per pound, its highest reading since Nov. 29.

Tuesday's hog slaughter totaled 492,000 head, up from 479,000 a week ago, the U.S. Department of Agriculture (USDA) reported. The government on Monday revised last week's hog slaughter downward by 30,000 head to 2.689 million head.

Wholesale pork prices declined for a second day. The USDA priced the pork carcass cutout late Tuesday at $88.55 per hundredweight (cwt), down 52 cents from Monday.

In the cattle market, CME live cattle futures ended higher but the benchmark April contract stayed below this week's 2-1/2-month top, settling up 0.525 cent at 181.750 cents per pound.

CME March feeder cattle jumped 2.700 cents to finish at 241.325 cents per pound.

Traders await the start of this week's cash cattle trade as well as the USDA's biannual cattle inventory report due on Wednesday. In July, the government reported the U.S. beef cattle herd at 29.4 million head, the smallest for that date in USDA records dating to 1971.

"We continue to cull the herd. This contraction is beginning to really make a difference as far as the beef production outlook," said Dennis Smith, commodity broker for Archer Financial Services.

U.S. wholesale beef prices fell by Tuesday afternoon, with choice cuts priced at $296.07 per cwt, down $3.35 from Monday, according to USDA data.

(Reporting by Julie Ingwersen; Editing by Sherry Jacob-Phillips)