Sternal recumbency or suspension by the hind legs immediately after delivery improves respiratory and metabolic adaptation to extra uterine life in newborn calves delivered by caesarean section

The aim of this study was to evaluate the effect of body positioning immediately after de- livery on respiratory and metabolic adaptation to extra-uterine life in newborn calves. One hundred and one Belgian White and Blue calves were delivered at term by an elective caesarean section and were assigned into three categories according to the body position imposed immediately after umbili- cal cord rupture: 71 calves were placed in lateral recumbency; 16 calves were placed in sternal recum- bency and 14 calves were suspended by the hind legs for less than 90 seconds (75 ± 5 s). Following this initial body position, the calves were allowed to move without restraint. They were examined at birth, 5, 15, 30, 45 and 60 minutes, and 2, 3, 6, 12 and 24 hours after birth by the following measure- ments: physical examination, heart rate, arterial blood gas analysis, pulmonary function tests using the esophageal balloon catheter technique, arterial and venous blood acid-base balance analysis, rec- tal temperature, jugular venous blood sampling for the determination of blood glucose, plasma lac- tate and serum cortisol concentrations, haematologic variables and passive immune transfer variables. Body positioning immediately after delivery clearly influenced respiratory and metabolic adaptation to extra-uterine life in term calves delivered by an elective caesarean section. Systematic sternal recumbency and suspension by the hind legs for less than 90 seconds immediately after umbil- ical cord rupture had a positive functional impact on postnatal pulmonary mechanics and gas ex- change and on postnatal correction of mixed acidosis present at birth, contributing in turn to an enhanced passive immune transfer. These two body positions should be encouraged to improve adap- tation at birth in healthy term calves delivered by an elective caesarean section. Evaluation of possible side-effects is required before application in severely asphyxiated calves.