It seems to me that the various sacrifices and processes reflect the diversity of testimonies among the elect. Each believer has a unique conversion experience. Not every child of God has the same intellect, environment, opportunities, distractions, education or heritage, yet everyone must come by a substitution sacrifice - Jesus. And, the ministers of God play varying roles in the conversion of His saints... some more; some less. But, the most important meaning of the different sacrifices appears to be the reflection that each one casts upon the ultimate sacrifice - Christ. Perhaps the young bull symbolized His strength. The sheep would surely represent His humility. The goat reminds us that He became sin for us. The dove might show us how innocent He was; the pigeon how poor. And, the types and figures go on and on... the fire of the altar speaks of God's holiness. The dissection of the sacrifice reminds us that God looks upon the inside, not the outside to find what pleases Him.
But, most glorious of all is the fact that the ancient Jewish disciples offered these sacrifices of their own voluntary will (Leviticus 1:3). It is the only kind of offering God desires - willing, not compulsory offerings. And, of course, Jesus is the ultimate volunteer in the area of sacrifice. He willingly offered Himself (John 10:18).