The argument is over whether the fact that we no longer slaughter animals demonstrates that that the commandments of God expressed in the Old Testament are obsolete. My position is that the demand for a blood sacrifice has not been abolished by the death of Christ on the cross, but rather it has been fulfilled.
"I did not come to abolish the law, but fulfill it," -- Jesus Christ.
"Not one jot or tittle of the law shall be repealed until the return of Jesus Christ in all his glory" -- St. Paul.
That is correct. The demand was fulfilled. The system which expressed that demand in the keeping of ceremonial laws was abolished.