The study, conducted by Iowa State University for the American Soybean Association (ASA), involved testing more that 1,300 samples from 30 soybean-growing states.
Results found that US soybeans carried average crude protein of 35.65 per cent and average vegetable oil content of 18.66 per cent - on a 13 per cent grain moisture basis.
"These are slightly above the long-term US averages of 35.42 per cent protein and 18.60 per cent oil," said the report. "The soybeans from the 2003 crop will produce, on average, 43.8 pounds of 48 per cent protein meal and 10.9 pounds of oil per bushel."
According to the ASA, the protein content of US soybeans was up from 35.42 per cent in 2002 - the highest figure seen in three years.
US soybean prices recently hit all time highs due to losses to the US soy crop as a result of hot and dry weather in the summer months.
Based on 1 October conditions, the US department of Agriculture said in October that production this year in the United States would shrink to 2.468 billion bushels, down sharply from an average of analysts' estimates for 2.578 billion and well below the government's forecast in September for 2.643 billion bushels.