Rachel is barren and upset that Jacob is spending so much time with Leah. So she gives Jacob her handmaid, Bilhah, and Jacob has two sons with her (Dan and Naphtali). Leah, not to be outdone, gives her handmaid, Zilpah, to Jacob and she has two sons (Gad and Asher). Leah’s son Reuben comes from the fields with Mandrakes. Rachel wants them badly enough that she allows Jacob to be with Leah again in exchange for them. Leah gets pregnant two more times and has Issachar and Zebulun. She also has a daughter named Dinah. Finally Rachel gets pregnant and has Joseph. Jacob asks Laban to let him go and to allow him to take some cattle with him. He is allowed to take any of the spotted cattle and goats. And Jacob again agrees to feed and tend to the flock another season. But he selectively breeds the cattle, sheep and goats through artificial insemination so that his are strong and Laban’s become weaker.
In other words:
Jacob has a bunch more children and decides it’s time to leave. Laban doesn’t want him to go and take the cattle. So Jacob agrees to work some more if he can have the spotted animals and then proceeds to make sure his are the strongest and the ones that will stay with Laban are weak.
Favorite and most interesting bit:
That Jacob was able to selectively breed the animals using artificial insemination, basically using a rod of poplar dipped in semen to conceive animals and he was basically able to create a flock that benefits him and sticks it to Laban who had been playing him and changing the deals with him for over 14 years.
Moral Lessons Learned:
Smart scientists can run circles around stupid con men any day! (Genesis 30: 43)