How does Pharaoh know?

Genesis 47:5 says, “And Pharaoh spake unto Joseph, saying, Thy father and thy brethren are come unto thee:

47:6 The land of Egypt is before thee; in the best of the land make thy father and brethren to dwell; in the land of Goshen let them dwell: and if thou knowest any men of activity among them, then make them rulers over my cattle.”  Why would Pharaoh give the best of the land of Egypt to a bunch of Israelites?  Especially if Jacob's family was an abomination in the eyes of the Egyptians because they were shepherds.  Moreover where did Pharaoh get the idea that they were cattle farmers?  They never said it to him but yet he puts them in charge of his cattle?  Isn’t this a just a little odd.  Did Pharaoh know that they were lying to him?