Both markets have fully recovered the losses incurred shortly after Japan's March 11 earthquake. In the days after that disaster, cattle futures lost about 6 percent of their value and hog futures more than 5 percent.

Fund buying pushed the markets to the day's highs, but it was cash market events that started futures higher.

In cattle, higher cash sales this week in Nebraska, the No. 2 cattle state behind Texas, at $190 per cwt on a carcass basis triggered buying in futures. As the futures rose short covering and chart-based buy orders were activated.

"If you were short, would you be happy right now?" said one cattle trader explaining the rush by some traders to buy back short positions.

Since the Japanese earthquake, wholesale beef prices rose to their highest since 2003, cash cattle traded higher from Texas to Nebraska, and Japan was back in the market buying US beef.

Also, Japan may need to buy more beef to replace meat that was either spoiled due to power outages or contaminated by the radiation leaks, said Dan Norcini, independent livestock trader.

USDA on Thursday reported Japan bought 3,900 tonnes on US beef last week, the largest sale to any country that week.

While beef demand is strong, the supply may decline, which could force cattle prices even higher, traders said. The US cattle herd is the smallest in more than 50 years and feedlot cattle numbers are expected to decrease in the months ahead.

April cattle futures closed up 2.775 cents, or 2.4 percent, at 118.600 cents per lb and actively traded June was up 2.975 cents, or 2.59 percent, at 117.750 cents.

April peaked Friday at 118.650 cents per lb the highest ever for a lead contract.

Feeder cattle moved higher with live cattle with March up 1.100 cents, or 0.84 percent, at 131.900 cents per lb and April up 2.225 cents, up 1.68 percent, at 134.850.

Hog futures advanced, with June contract the highest in a month, helped by this week's higher pork prices and by talk of pork plants needing hogs to maintain production schedules.

Also, a USDA report on Friday showing a $7.37-per-cwt increase in the average Iowa/Minnesota cash hog price helped push futures higher. Cash and futures traders speculated that jump in cash may reflect a price increase over a few days.

The USDA Hogs and Pigs Report, that was released after the close, appeared to have little affect on Friday's futures trading. The report showed about 1 percent more hogs on US farms as of March 1 than a year ago and a breeding herd about unchanged from a year ago.

April hogs closed up 2.150 cents, or 2.27 percent, at 92.475 cents per lb and June up 2.525 cents, or 2.5 percent, at 103.700.