After owning cattle for several yrs I was presented with twin calves. It took a little while for me to get someone to assist me & it turned out the 1st twin was breach. 1st calf was DOA & second calf was barely breathing. It's air passageway was full of mucus. After hanging upside down a short time to aid in fluid drainage it stopped breathing. Oh well if one owns livestock one is going to lose a few but it's always saddening.