Jews today no longer offer sacrifices because they no longer have a proper place to do so. Yaweh is rather specific in his requests about where sacrifices can be offered, and the last place he specified was the temple in Jerusalem. When the Romans destroyed the temple around 70 C.E. the sacrificial rituals stopped, because offering a sacrifice improperly would be considered a sin. Orthodox Jews pray for the restoration of the temple in Jerusalem and the resumption of the rituals that were performed there. This includes the sacrifice. This may sound cruel, but since the either the preists or the family of the man offering the sacrifice normally eat the animal, and it is slaughtered in a manner similar to that which animals are slaughtered for food (the draining of the blood through the carotid artery) it wouldn't necessarilybe considered cruel or wasteful.
Currently there is a mosque on the site of the old temple in Jerusalem which prevents the re-building of the temple.
Also, the practice of tithing has its roots in Deut. and Genesis, so it wouldn't really be a mistake to read that concept onto sacrifice. It was also common practice for a landowner to collect a 10% fee from those farming his land. Similarly if one king aided another in battle, and the latter was victorious, the king who came to his assistance was entitled to a percentage of the spoil. This process could easily be applied to a deity as well.
