Alaska Air does it all the time:
Antlers and horns are only accepted as checked baggage if they are properly packaged and meet normal size and weight restrictions.
Antlers must be wrapped in shrink wrap or plastic covering.
Antler tips must be padded to prevent punctures.
Antlers must be free of raw meat, blood, or noticeable odors.
Linear dimensions must not exceed 120 inches (305cms). Any animal rack/antler that exceeds 120 linear inches cannot be accepted.
Maximum allowable dimensions are 38 inches deep by 34 inches wide and 70 inches length/height.