According to the Old Testament, one of the reasons why the House of Israel chose to spurn the House of Judah was due to the latter's vile obsession not only with war but with human and animal sacrifice. One can split the Old Testament prophets into camps based upon whether they speak for the Judites or whether they remonstrate against them and their heinous practices. The Israelite prophets Amos, Hosea, and Jeremiah, were the staunchest opponents of the House of Judah (David) and throughout their narratives they cajole the Judites, imploring them to abandon their godless practices, particularly the sacrifice of their firstborn sons.
The bull, being symbolic of earthiness, represented his own gross constitution which must be burned up by the fire of his Divinity. (The sacrificing of beasts, and in some cases human beings, upon the altars of the pagans was the result of their ignorance concerning the fundamental principle underlying sacrifice. They did not realize that their offerings must come from within their own natures in order to be acceptable.)
As development of the wool industry made it more profitable to keep sheep alive for their fleeces than to kill them for their meat, the goat became a more popular sacrificial victim.