Lean-hog futures ended higher Monday, led by the summer contracts and supported by expectations for strong pork exports to take additional product off the domestic market and push hog prices up.

Spillover from gains in live cattle, feeder cattle and stock prices helped boost lean hogs as well.

April, the front-month hog contract at the Chicago Mercantile Exchange, posted a modest gain, closing up 0.07 cent at 88.40 cents. Most-actively-traded June was up 1.15 cents, or 1.2%, at $1.0097 a pound.

Japan may have problems with radiation further across northern areas of the country following the earthquake and tsunami that damaged a nuclear-power plant. If livestock or products from the animals are found to have higher-than-allowed levels of radiation and deemed unsuitable for consumption, the Japanese may need to purchase more U.S. pork, a broker said.

Exports should stay strong, and the beginning of the seasonal rally may have already kicked off based on recent gains in wholesale pork prices, said Dan Norcini, an independent trader. The U.S. Department of Agriculture's pork cutout value climbed late last week, and on Friday hit its highest level since Aug. 30.

Some hedge selling was seen in the summer months during the session as producers and others locked in the higher prices for their hogs this summer. Still, June through August hit 1 1/2-week highs and closed near their respective session highs.

Cash hog prices were reported mostly flat with some higher bids seen possible for later in the week amid seasonally tightened supplies. The market trend is expected to track upward into the spring and summer once the peak of supplies from the fall farrowings has been processed. The more rapid run-up in cash prices may not occur until mid or late April but the market could move gradually higher in the near-term, analysts said.