Genesis 30:38 He set the rods which he had peeled opposite the flocks in the gutters in the watering-troughs where the flocks came to drink. They conceived when they came to drink. (WEB KJV JPS ASV WBS YLT NAS)

Genesis 30:41 It happened, whenever the stronger of the flock conceived, that Jacob laid the rods before the eyes of the flock in the gutters, that they might conceive among the rods; (WEB KJV JPS ASV DBY WBS YLT NAS)