Thematic Bible: Facts about breeding

That very day, Laban removed the male goats that were striped or spotted, all the female goats that were speckled or spotted that is, every one that had white on them and all the black lambs and placed them into the care of his sons. He sent them as far away from Jacob as a three days' journey could take them. Meanwhile, Jacob kept tending the rest of Laban's flock. Jacob took branches from white poplar trees, freshly cut almond trees, and some other trees, stripped off their bark to make white streaks, and uncovered the white part inside the branches. read more.
Then he placed the branches that he had stripped bare in all the watering troughs where the flocks came to drink. He placed the branches in front of the flock, and they went into heat as they came to drink. When the flocks mated in front of the branches, they would bear offspring that were striped, speckled, or spotted. Jacob kept the lambs separate, facing the striped and entirely black ones that belonged to Laban's flock. He set his own herd by itself and would not let them be with Laban's flock. Whenever the more vigorous of the flock came into heat, Jacob would place the branches in the troughs in front of the flock to make them mate by the branches. But he didn't put the branches in front of any of the feeble members of the flock. As a result, the feeble ones belonged to Laban, but the stronger ones belonged to Jacob. Therefore the man Jacob prospered so much that he had large flocks, female and male servants, as well as camels and donkeys.

"When Laban said, "The speckled ones will be your wages,' then all the flock gave birth to speckled ones. Then when he said, "The streaked ones will be your wages,' all the flock gave birth to streaked offspring. "So God has taken away your father's livestock and has given them to me.