Suspending the Newborn Calf.
While a common practice among lay people, suspending the calf by the hind legs is not recommended. In doing so the full weight of the viscera is on the diaphragm of the calf, and compresses the lungs. This makes it more difficult for the calf to breathe (expand its lungs) rather than easier. There is no fluid in the lungs of the newborn calf, they are consolidated (atelectic) prior to the first breath. There is a small amount of mucus in the trachea and the nostrils. The latter can be squeezed by stripping the nasal passages from the eyes towards the nostrils. Mucus seen running from the mouth and nose of the suspended calf is actually amniotic fluid coming from the stomach. [Meconium staining denotes intrauterine hypoxia].
Drost M (1966)