Liver in bologna.

[LWP]

While looking through different bologna recipes I'm considering trying, I noticed that in Len Poli's recipe he calls for 1/4 lb. of liver in addition to the 3 lbs. of beef and 2 lbs. of pork. Does anybody know what the role this small ratio of liver plays in the final result? My guess is that it would lend a bit of familiar commercial flavor since most commercial bolognas are just assorted animal parts pureed together but I have no idea if that's even close to correct. He does say in the recipe that those not wanting to use the liver can substitute bacon instead.