EFFECT OF THE LEVEL OF ASPHYXIA DURING DELIVERY ON VIABILITY AT BIRTHAND EARLY POSTNATAL VITALITY OF NEWBORN PIGS

Newborn pigs (n = 117) were used to provide information on the relatio nships of degree of asphyxia during delivery, viability at birth, and some striking aspects of postnatal vitality including survival, interv al between birth and first udder contact and between birth and first s uckling, rectal temperature at 24 h of life (RT(24)), and growth rate over the first 10 d of life. The degree of asphyxia at birth was estim ated from cord blood pCO(2), pH, and lactate levels. Onset of respirat ion, heart rate, skin color, and attempts to stand during the first mi nute after birth were used to estimate the viability score. Neonatal a sphyxia, i.e., decreased blood pH and increased blood pCO(2) and lacta te, was associated with the production of unusually high levels of cat echolamines. The degree of asphyxia increased with late position in th e birth order (P < .01) and was higher in piglets born posteriorly (P < .05). Further, the average blood pCO(2) within a litter increased (P < .05) with litter size. There was an inverse relationship between th e degree of asphyxia and the viability score (P < .001). Highly viable piglets reached the udder more rapidly (P < .001) and had a higher RT (24) (P < .001) than those of low viability. Plasma glucose concentrat ions increased with blood pCO(2) and plasma epinephrine concentrations (P < .001). Neonatal asphyxia reduced postnatal vitality by delaying the first contact with the udder (P < .03) and was associated with a l ower RT(24) (P < .05), growth rate(P < .001), and survival over 10 d ( P < 0.06). These variables, i.e., interval between birth and first udd er contact, RT(24), and growth rate, were correlated with birth weight (P < .001); RT(24) was also shown to decrease (P < .001) with the tim e taken to reach the udder. Overall, results suggest that piglets suff ering from asphyxia during delivery are less viable at birth and less prone to adapt to extrauterine life.