Calving duration and obstetric assistance influence pulmonary function of Holstein calves during immediate fetal-to-neonatal transition.

Neonatal immediate adaptation to extrauterine life depends mainly on adequate lung function, which is under the influence of previous fetal maturation and obstetrical condition, both acting to stimulate the efficient liquid removal from the pulmonary parenchyma during the immediate transition period. The objective of the present study is to identify chest radiographic changes of neonatal calves born under the influence of different duration of calving and obstetric assistance and correlate with clinical analysis and blood acid-base balance. Experimental groups were determined according to the duration of calving: 2 h (n  =  16), 2-4 h (n  =  16) and >4 h (n  =  12), and additionally by two sub-groups: no-intervention calving (n  =  22) and intervention calving (n  =  22).