Genesis 30:41-43

41And it came to pass, whenever the stronger livestock conceived, that Jacob placed the rods before the eyes of the livestock in the gutters, that they might conceive among the rods.

42But when the flocks were feeble, he did not put them in; so the feebler were Laban’s and the stronger Jacob’s.

43Thus the man became exceedingly prosperous, and had large flocks, female and male servants, and camels and donkeys.