In before Georgio Tsoukalos.
From the description, extraterrestrials and satanic rituals are more likely and bird predation unlikely.
Interestingly, this phenomenon is not isolated to cattle. Wild animal males and females have also been dissected for particular organs, done in a way even our best medical science could not do it. The moose carcasses have been very heavy with no markings where hoisting tools were used and the re are incision points under the carcass, as if the heavy animal was off the ground then let down or dropped after the removals. In some cases the heart has been removed WITHOUT cutting or tearing the sac which encases the heart.