CHICAGO, March 3 (Reuters) - Chicago Mercantile Exchange livestock futures slumped on Thursday, with live cattle and feeder cattle setting four-month lows.

The cattle markets came under continued pressure from weakness in equities, which lost ground as the Ukraine crisis kept investors on edge, traders said.

In grain markets, soaring costs for corn and wheat threaten to raise production costs for livestock producers that use the crops for feed. Meanwhile, prices for boxed beef shipped to wholesale buyers tumbled.

CME April live cattle ended 1.750 cents weaker at 138.350 cents per pound and reached its lowest price since Nov. 2. March feeder cattle dropped 1.950 cents to 156.350 cents per pound and touched its lowest price since Nov. 2.

In the boxed beef market, choice cutout values fell by $1.37 to $254.35 per cwt, while the select cutout sank by $3.55 to $247.79 per cwt, the U.S. Department of Agriculture (USDA) said.

The USDA, in a separate weekly report, said net export sales of U.S. beef in the week ended Feb. 24 reached 23,800 tonnes for 2022. That was up 64% from the previous week and 23% from the prior four-week average.

Weekly U.S. pork export sales were 42,200 tonnes for 2022, up 59% from the previous week and 80% from the prior four-week average, the USDA said.

CME April lean hog futures closed 1.1 cents down at 105.200 cents per pound, while June hogs ended up 0.050 cent at 116.500 cents per pound.

In other news, billionaire activist investor Carl Icahn is broadening a push to get McDonald's Corp to improve suppliers' treatment of pigs raised for bacon and sausage. (Reporting by Tom Polansek in Chicago; Editing by Subhranshu Sahu)