'Gutters' in the Bible

and setteth up the rods which he hath peeled in the gutters in the watering troughs (when the flock cometh in to drink), over-against the flock, that they may conceive in their coming in to drink;

And it hath come to pass whenever the strong ones of the flock conceive, that Jacob set the rods before the eyes of the flock in the gutters, to cause them to conceive by the rods,