Hog and cattle prices this year will be higher than previously forecast as meat supplies tighten, partly because harsh winter weather hampered animals’ weight gain, USDA said in a report today.

Hogs will average $47 to $50 per hundredweight, national base, live equivalent 51-52 percent lean, up from $46 to $49, according to the USDA’s monthly World Agricultural Supply and Demand report.

Prices for choice steers are expected to average $87 to $92 per hundred pounds in 2010, up from $85 to $91 in a prior forecast.

The USDA also reduced its 2010 forecasts for U.S. beef and pork production and trimmed the 2009 corn harvest by 20 million bushels, to a still-record 13.131 billion bushels.

Snowstorms hit much of the central U.S. during January and February, slowing shipping and forcing animals to eat more to stay warm.

“Winter weather has stressed cattle in many parts of the country, which is reflected in lighter carcass weights,” the USDA said. As with cattle, slaughter-ready hog weights were lighter than expected, the USDA said.

Total beef production is projected at 25.747 billion pounds, down from a previous estimate of 25.752 billion pounds and down 1.2 percent from 25.065 million pounds in 2009, the USDA said.

Pork production was reduced to 22.45 billion pounds from 22.54 billion pounds. The new 2010 forecast is down 2.4 percent from production of 23.01 billion pounds in 2009.

Export forecasts for beef and pork were unchanged from last month, at 2.04 billion pounds and 4.5 billion pounds, respectively.

“Although the recent resolution of pork sanitary issues will permit exports to Russia, exports to that market will be limited by import quotas,” the USDA said.

“Cow slaughter is relatively low and January milk cow numbers were higher than expected,” the USDA said. The pace of herd reduction “slowed from last month.”

A slide in corn prices in recent months has already provided a boost for livestock producers’ profit outlook, and they may see further benefit amid lower than expected overseas demand, USDA data showed.

The USDA cut its forecast for U.S. corn exports during the 2009-10 marketing year, to 1.9 billion bushels from 2 billion bushels, and raised ending stocks, to 1.799 billion bushels from 1.719 billion bushels.

Farm prices for corn are expected to average $3.45 to $3.75 per bushel in 2009-10, down from a previously-forecast range of $3.45 to $3.95, the USDA said.

Read the full report.