Whenever the stronger females of the flock were in heat, Jacob would place the branches in the troughs, in full view of the animals, so that they would breed in front of the branches.
Jewish Publication Society of America Version (JPS1917) - Genesis 30:41 >And it came to pass, whensoever the stronger of the flock did conceive, that Jacob laid the rods before the eyes of the flock in the gutters, that they might conceive among the rods;