The amount of freight moved last month fell for the first time since April, according to newly released figures.

The American Trucking Associations’ advanced seasonally adjusted For-Hire Truck Tonnage Index slipped 0.4% in July after edging 0.1% higher in June.

The index registered 125.4 for the month versus 125.9 in June, the highest level on record. Compared with July 2012, the index increased 4.7%, which is robust, although the smallest year-over-year gain since April.

Year-to-date, compared with the same period in 2012, the tonnage index is up 4.7%.

The not seasonally adjusted index, which represents the change in tonnage actually hauled by the fleets before any seasonal adjustment, equaled 129.6 in July, which is 3% above the previous month at 125.9.

“After gaining a total of 2.2% in May and June, it isn’t surprising that tonnage slipped a little in July,” said ATA chief economist Bob Costello. “The decrease corresponds with the small decline in manufacturing output during July reported by the Federal Reserve last week.”

“Despite the small reprieve in July, we expect solid tonnage numbers during the second half of the year as sectors that generate heavy freight, like oil and gas and autos, continue with robust growth,” Costello said.

“Home construction generates a significant amount of tonnage, but as mortgage rates and home prices rise, growth in housing starts will decelerate slightly in the second half of the year, but still be a positive for truck freight volumes,” he said. “Tonnage gains in the second half of the year are likely to overstate the strength in the economy as these heavy freight sectors continue to outperform the economy overall.”