Source: Insight On The Scriptures
The sacrifices commanded under the Law covenant all pointed forward to Jesus Christ and his sacrifice or to benefits that flow from that sacrifice. (Heb 8:3-5; 9:9; 10:5-10) As Jesus Christ was a perfect man, so all animal sacrifices were to be sound, unblemished specimens. (Le 1:3, 10; 3:1) Both the Israelite and the alien resident who worshiped Jehovah were included in presenting the various offerings.Nu 15:26, 29.
Now, just because sacrifices were acceptable does not mean that abuse or inhumane treatment of the animals were. Don't forget that just killing an animal does not signify inhumane treatment.
The Bible inculcates just and merciful treatment of the lower creatures. Indeed, Almighty God represents himself as the Loving Provider for their lives and well-being. (Pr 12:10; Ps 145:15, 16) The Mosaic Law enjoined proper care of domestic animals. When found straying, domestic animals were to be returned safely to their owner; when crushed under a burden, they were to be relieved. (Ex 23:4, 5) They were to be worked humanely. (De 22:10; 25:4) They, as well as man, were to benefit from the Sabbath rests. (Ex 20:10; 23:12; De 5:14) Dangerous animals were to be controlled or destroyed. (Ge 9:5; Ex 21:28, 29) Crossbreeding of different sorts was forbidden.Le 19:19.