Acid–base balance of umbilical artery blood of liveborn piglets at birth and its relation with factors affecting delivery of individual piglets

In the limited number of studies that reported on the relation between factors affecting birth of individual piglets and acid–base balance values at birth, predominantly simple correlation coefficients have been used. The aim of the present study was to analyse the relation between factors affecting delivery of individual liveborn piglets and acid–base balance values (pH, pCO2pCO2, HCO3− and BEecf) at birth. In total 201 piglets originating from 44 litters were used for the collection of blood samples from the umbilical artery immediately after birth, preferably in the period of apnea. Blood samples were analysed with the iStat® Portable Clinical Analyser.Significantly lower pH, HCO3−, BEecf and significantly higher pCO2pCO2 levels were found in posteriorly presented piglets, independently of the condition of the umbilical cord, birth weight and cumulative birth interval/rank. Independently of presentation, birth weight and rank, piglets born with ruptured umbilical cords showed significantly lower pH values. Next to that, increasing birth weights resulted in increasing HCO3− and BEecf values at birth, independently of presentation, condition of the umbilical cord and cumulative birth interval/rank. Both an increase in cumulative birth interval and in rank was associated with a significant decrease of pH, HCO3−, BEecf and increase of pCO2pCO2 levels in umbilical cord blood at birth.Together these results demonstrate for the first time that a clear relation exists between (factors affecting) the progress of delivery and acid–base balance values in a polytocous species like the pig.