Joseph Smith taught that the Law of Sacrifice would be restored:
However, in 1840, Joseph took a different position. He argued that literal animal sacrifices would be an ongoing part of the restored priesthood before and even after the second coming of Christ:
"Thus we behold the keys of this Priesthood consisted in obtaining the voice of Jehovah that He talked with him [Noah] in a familiar and friendly manner, that He continued to him the keys, the covenants, the power and the glory, with which He blessed Adam at the beginning; and the offering of sacrifice, which also shall be continued at the last time; for all the ordinances and duties that ever have been required by the Priesthood, under the directions and commandments of the Almighty in any of the dispensations, shall all be had in the last dispensation, therefore all things had under the authority of the Priesthood at any former period, shall be had again, bringing to pass the restoration spoken of by the mouth of all the Holy Prophets; then shall the sons of Levi offer an acceptable offering to the Lord...
... it is generally supposed that sacrifice was entirely done away when the Great Sacrifice [i.e.,] the sacrifice of the Lord Jesus was offered up, and that there will be no necessity for the ordinance of sacrifice in future; but those who assert this are certainly not acquainted with the duties, privileges and authority of the Priesthood, or with the Prophets.
The offering of sacrifice has ever been connected and forms a part of the duties of the Priesthood. It began with the Priesthood, and will be continued until after the coming of Christ, from generation to generation. We frequently have mention made of the offering of sacrifice by the servants of the Most High in ancient days, prior to the law of Moses; which ordinances will be continued when the Priesthood is restored with all its authority, power and blessings...
These sacrifices, as well as every ordinance belonging to the Priesthood, will, when the Temple of the Lord shall be built, and the sons of Levi be purified, be fully restored and attended to in all their powers, ramifications, and blessings. This ever did and ever will exist when the powers of the Melchizedek Priesthood are sufficiently manifest; else how can the restitution of all things spoken of by the Holy Prophets be brought to pass. It is not to be understood that the law of Moses will be established again with all its rites and variety of ceremonies; this has never been spoken of by the prophets; but those things which existed prior to Moses' day, namely, sacrifice, will be continued.
It may be asked by some, what necessity for sacrifice, since the Great Sacrifice was offered? In answer to which, if repentance, baptism, and faith existed prior to the days of Christ, what necessity for them since that time? The Priesthood has descended in a regular line from father to son, through their succeeding generations.”—Joseph Smith (Oct. 5, 1840), in Teachings of the Prophet Joseph Smith,, 171-73.