U.S. economic growth braked more sharply than expected in the first quarter as harsh weather dampened consumer spending and energy companies struggling with low prices slashed spending, but there are signs activity is picking up. A strong dollar and a now-resolved labour dispute at normally busy West Coast ports also slammed growth, the government said. “A stalling of U.S. economic growth at the start of the year rules out any imminent hiking of interest rates by the Fed,” said Chris Williamson, chief economist at Markit in London.