For a while there was the notion that animals only learnt to kill from man. I don't know if that meant animals were perfect and sinless too and also would live forever. If animals wouldn't kills for food would they eat things that had died? What would happen to all the bodies that didn't get cleaned it? At one level does "eating" happen ... mammals ... rodents and earthworms ... mites ...
The trouble with religion is there is no cohesive story. It's a mishmash with parts that change to try to deal with other contradictions. It never makes sense as a whole.