The Canadian dollar weakened against the greenback on Friday, and the yield on benchmark government debt slipped. The loonie was trading 0.5% lower at C$1.3764 to the greenback, or 72.65 U.S. cents, after trading in a range of 1.3683 to 1.3771. Canadian government 10-year bond yields fell 9 basis points to 3.644%. The yield on similar U.S. government benchmark debt fell to 4.5033%. U.S. May crude futures rose $1.71 to $86.73 a barrel on Friday.