Today thru medical science & DNA study, we're learning undoubtedly, that GOD knew things about the "Lamb" that til now, was IMPOSSIBLE that ANY "man" could've known.. & yet the Bible is our record that once again, God was telling us all along! There are several reasons why "God" chose the "Lamb" above all other animals as closest comparison to "Christ".. & there's a reason that science can confirm, why GOD preferred the sacrifice of a LAMB in the Old Covenant, above any other animal as a symbolic sacrifice. Here's "some" of what mainstream science has learned about the "Lamb" in recent years:

The first mammal to be successfully cloned & live into adulthood using "human" host cells was a LAMB nicknamed "Dolly." The scientists behind the project found that no other "known" animal shared a closer genetic makeup on a molecular scale, than a lamb.. making it the best viable candidate for success. Something else remarkable about the LAMB is that there are but 2 choice animals that can tolerate almost "any" venomous snakebite.. they are, the horse & the LAMB. This is important because these animals are actually how our "Anti-venoms" are developed to treat humans who become prey to poisonous snakebites. The anti-venom is developed by injecting the snake venom directly into the animal & giving time for their blood to fight it & build up immunity to it. The "immunized blood" is then withdrawn & the necessary elements to create human vaccinations are extracted & dispensed in the lab.. But there's more:

In the early 1980's the FDA outlawed use of horses in development of anti-venom due to the fact that far more horses fail to fight off certain snake venom than do those developed in the bloodstream of a LAMB. To date, the only approved anti-venom in the U.S. for treatment of snakebite are those manufactured in the lab from a LAMB's blood. If that's not enough, read up on a very recent "breakthrough" anti-cancer drug called "Prolarix" developed by Pfizer Pharmaceuticals.. & guess how this soon-to-be "game-changing" drug is being developed...?... You guessed right.. using the LAMB.

It's no wonder that God chose a "lamb" in Old Covenant sacrifice to symbolize "Jesus Christ" who would later broker the New Covenant under the same symbolism of being the "Lamb of God." In the Old Covenant, it now would seem that no other animal could come as close to the sacrifice of a human life than a LAMB, since there's more compatibility between a Lamb's Blood & a Human's.. than any other animal.. yet God did not ask for, nor expect one single human sacrifice aside from His own son.. but temporally accepted the "sacrificial lamb" in Old Testament times in proxy. It's also no wonder that Jesus (Yeshua) the Christ was born in an humble stable, where other lambs likely were held. There's too many parallel's to the medical power in the blood of a natural lamb to that of the Almighty Power in the Pure & Precious Blood of the LAMB OF GOD, for it to be coincidence. To this day, a natural LAMB's blood is used to manufacture anti-venom & perhaps the most effective anti-cancer drug that will hit the shelves.

Since lamb's blood is being used to defeat poison.. cancers.. It's no wonder that John the Baptist said in John 1:29 "Behold the Lamb of God, which taketh away the sin of the world." JESUS.. the only SINLESS Blood Sacrifice, can take away the bite of the snake.. fight & DEFEAT this spiritual cancer we call "SIN." Jesus alone is/was IMMUNE to SIN.. & no other blood will overcome the spiritual death that the poison of sin brings, BUT for the BLOOD of the LAMB of GOD! Worthy, Worthy is the Lamb!
-Kenny Griffin

(some of the sources for my research are in links below for your reference)
http://www.prnewswire.com/.../global-liver-cancer-drugs... http://novaonline.nvcc.edu/.../dolly96/Dolly_Module.html http://www.sheep101.info/bloodsheep.html