Prediction of vitality and survival of newborn lambs using a modified Apgar score

Abstract

The Apgar score is widely used for global evaluation of the neonate in a minimally invasive way, it assesses neonatal vitality through a range of scores on clinical signs of health and vitality, such as reflexes, respiration rate, and mucosal coloration. The neonatal period is fundamental for lambs survival, that is dependent on complex interactions between maternal ability and newborn viability, as newborn lambs require milk and immunological protection that are dependent of mutual maternal-filial behaviour. The aim of this study was to determine the vitality of Suffolk newborn lambs by the modified Apgar method. Thirty-seven ewes were used and their lambs were classified at 5 min of age by the modified Apgar method. The ewes' body condition score, number of lambs born, and birth weight were recorded. Behaviour was evaluated by measuring, in minutes, the intervals between birth and sternal recumbency, the adoption of quadrupedal position, time until first suckling, and duration of first suckling. Blood samples were collected from the lambs between 24 and 36 h of age to determine gamma-glutamyltransferase activity. Of the 37 births observed, 20 were singles and 17 twins, resulting in 54 newborn lambs, which 27 were classified as high, 11 as moderate and 16 as low Apgar, and the percentages of deaths were 8% (n = 1), 10 % (n = 2) and 81.25 % (n = 13), respectively. The causes of death were: starvation-hypoglycemia-hypothermia complex (10/16, 62.5 %), pneumonia (3/16, 18.75 %), and stillbirth (3/16, 18.75 %). The concentration of gamma-glutamyltransferase in the lamb′s serum with low Apgar was significantly (p-value 0.0027) lower (462.4 IU/L) than in lambs born with moderate (1616.8 IU/L) and high (3177.7 IU/L) Apgar. Birth weight (r = 0.39 and p = 0.0015) and APGAR (r = 0.61 and p < 0.0001) were correlated with survival. The vitality evaluation did predict survival ability and passive immunity transfer characteristics.