concrete products also rose following no change a month earlier. Treated wood prices turned up after falling in the preceding month. The indexes for asphalt felts and coatings and for mineral wool for structural insulation declined less in May than they had a month earlier.   ; Prices for intermediate foods and feeds inched up 0.1 percent following a 0.5-percent increase in April. The beef and veal index advanced 1.0 percent after moving up 2.4 percent in the previous month. Flour prices also rose less in May than they had a month earlier.   ; The index for prepared animal feeds decreased more than it had in April, and prices for processed young chickens turned down in May after advancing in the prior month. By contrast, prices for dairy products climbed 4.5 percent subsequent to a 1.6-percent increase in April. The index for shortening and cooking oils also rose more than it had in the preceding month. Prices for pork and for sausage and deli meats turned up in May after declining in the previous month.   ; Crude goods The Producer Price Index for Crude Materials for Further Processing increased 2.0 percent in May after falling 1.5 percent in the preceding month. This reversal can be traced to the index for crude energy materials, which rose following a decline in April. By contrast, slightly counteracting the upturn in crude goods prices, the indexes for crude foodstuffs and feedstuffs and for crude nonfood materials less energy advanced less in May than they had in April.   ; Prices for crude energy materials jumped 4.3 percent in May after dropping 4.9 percent in the prior month. This upturn is attributable to the natural gas index, which climbed 6.6 percent following a 13.0-percent decrease in April. By contrast, crude petroleum prices moved up 1.9 percent in May compared with a 7.9-percent rise a month earlier. For the second consecutive month, the coal index inched up at a 0.2-percent rate.   ; The index for crude foodstuffs and feedstuffs increased 1.1 percent in May after advancing 1.3 percent in April. In May, higher prices for fluid milk, slaughter broilers and fryers, corn, soybeans, and fresh fruits and melons outweighed lower prices for fresh and dry vegetables, slaughter hogs, and unprocessed shellfish.   ; The index for crude nonfood materials less energy edged up 0.1 percent in May following a 0.4-percent increase in April. In May, rising prices for copper base scrap, wastepaper, aluminum base scrap, and for construction sand, gravel, and crushed stone slightly outweighed declining prices for iron and steel scrap, raw cotton, gold ores, and for hardwood logs, bolts, and timber.