U.S. biodiesel production fell to 140 million gallons in April from 147 million gallons a month earlier, the U.S. Energy Information Administration said in a report on Friday. Soybean oil remained the largest biodiesel feedstock, with 520 million lbs used in April, or about 48 percent of the total. In March, soyoil used in biodiesel production was 624 million lbs. Chicago Commodities Desk