WASHINGTON — Changes in prices of dairy products were modest in the week ending July 27, compared to the previous week, the U.S. Department of Agriculture said in its July 31 National Dairy Products Sales Report. Grade AA butter averaged $1.45 a lb as of July 27, up 1c from the previous week.

US 40-lb blocks of cheddar cheese averaged $1.69 a lb for the most recent week, up 0.8c from the previous week, the U.S.D.A. said. US 500-lb barrels adjusted to 38% moisture averaged $1.71 a lb as of July 27, up 2c from the previous week.

Dry whey prices meeting U.S.D.A. Extra Grade standards averaged 57.9c a lb in the latest week, a decline of 0.3c from the previous week.

Nonfat dry milk prices meeting U.S.D.A. Extra Grade or Grade A standards averaged $1.75 a lb in the latest week. The price per pound increased 1.2c from the previous week, the U.S.D.A. said.