Physiological and metabolic responses in newborn piglets associated with the birth order.

The objective of this study was to evaluate the effect of birth order on the physiological and metabolic responses of the newborn piglet the first hours after birth. A total of 281 randomly selected newborn piglets were included, classified according to birth order in 12 groups (L1-L12). The expulsion interval, neonatal vitality, latency in connecting to the maternal teat and physiological profile were recorded for each piglet. The number of piglets born alive and dead was also recorded. The blood gases, electrolytes and glucose levels of the neonates were obtained by means of an automatic blood gas and electrolyte analyzer. Groups L1, L2, L11, and L12 had the least score on the vitality scale, the longest expulsion intervals, and longest latency to connect with the maternal teat, as well as greater physiological alterations (hyperglycemia, hyperlactatemia and hypercapnia) compared to groups L4 to L9. Likewise, type-II stillbirths only occurred in the first and last quarter of the birth order of the litter. In conclusion, piglets born in the first and last quarter of the birth order of the litter had a greater risk of having physiological and behavioral alterations during farrowing.