Association between birth order, blood pc02 and β-endorphin concentration in newborn piglets

Abstract

Parturition and delivery are stressful situations for the mother as well as the neonate. In newborn human babies and lambs, high plasma β-endorphin (β-EP) concentrations have been found, especially in conjunction with foetal distress. Foetal anoxia during parturition causes decreased blood pH, increased pC02, decreased piglet viability and stillbirth. Since high opioid levels can cause respiratory and circulatory difficulties. Piglets born later in the litter during prolonged parturition are more likely to suffer from these problems. It was, therefore, of interest to us to investigate whether late birth order and anoxia were associated with elevated plasma β-EP concentrations in newborn piglets.