Venous blood gas parameters in healthy Mediterranean buffalo calves in the first 72 hours of life

Abstract

In the first hours after calving the neonate radically modifies its anatomy and physiology to adapt to extrauterine life. These modifications, however, make the calf prone to respiratory and metabolic dysfunction. Thus, stillbirth, defined as the death of the neonate within 48 h after birth, represents a relevant issue for buffalo farming. Of the clinical procedures, the blood gas analysis of venous samples provides useful information regarding the acid-base status of the neonate, allowing the optimal management of potential illness calves. However, the blood gas parameters have never been studied in the buffalo calf in the first 72 h of life. Thus, this study aimed to report blood gas parameters at calving and 1, 12, 24, and 72 h after birth in healthy buffalo neonates born after normal parturition. The study involved 20 healthy buffalo calves, born from normal pregnancy and parturition. The parturition and the first hours after were monitored by closed-circuit television cameras, and within 1 min after calving the buffalo neonate received a clinical evaluation (APGAR, temperature), venous blood sampling for blood gas (pH, partial pressure carbon dioxide - pCO2, partial pressure oxygen - pO2, base excess, bicarbonate concentration, oxygen saturation, total carbon dioxide - tCO2, and lactate), and glycemia analysis. The same evaluations were performed after 1, 12, 24, and 72 h. The present study showed a moderate mixed acidosis at calving, similar to that reported in the bovine neonate, likely due to the high venous blood pCO2 and lactate. This acidemia resolved spontaneously within 12 h as a reduction of pCO2 (P ≤ 0.05). Lactate reduced significantly (P ≤ 0.05) only at 72 h, similarly to the trend reported previously for the bovine calf. Blood lactate concentration was correlated with glycemia at calving and 1 h (r = 0.677, P = 0.014), and with stage 2 duration (r = 0.647, P = 0.006). These findings support a possible mechanism of glucose generation induced by catecholamines coupled to anaerobic metabolism soon after calving. After calving, all the blood gas parameters changed rapidly reaching values comparable with those reported in the literature for older buffalo calves from 72 h after calving. No correlations were found between APGAR score and venous blood gas parameters, likely due to the inclusion criteria that selected only health buffalo calves born after normal parturition. The findings suggested that the venous blood gas analysis could be considered supportive rather than an alternative to the clinical evaluation of the buffalo calf.