Genesis 30:37-39

37Jacob then took branches of fresh poplar, almond, and plane wood, and peeled the bark, exposing white stripes on the branches.

38He set the peeled branches in the troughs in front of the sheep — in the water channels where the sheep came to drink. And the sheep bred when they came to drink.

39The flocks bred in front of the branches and bore streaked, speckled, and spotted young.