Genesis 30:41

Whenever the stronger of the flock were breeding , Jacob would lay the sticks in the troughs before the eyes of the flock , that they might breed among the sticks ,

Whenever the stronger females were in heat, Jacob would place the branches in the troughs in front of the animals so they would mate near the branches,

And it came to pass, whensoever the stronger cattle did conceive, that Jacob laid the rods before the eyes of the cattle in the gutters, that they might conceive among the rods.