IGF-I, NEFA and cortisol plasma concentrations in newborn donkey foals

Many hormonal and metabolic factors are involved in the neonatal adaptation and have been studied in several species, but knowledge are lacking for the donkey. IGF-I, NEFA and C are involved in the perinatal development in several species, but their role in the neonatal adaptation in donkey foals is unknown. The aim of this study was to investigate IGF-I, NEFA and cortisol (C) plasma concentrations in new-born Martina Franca donkey foals. Blood samples were collected 10 min after birth, at 12 h, 3, 7, 10, and 14 days of age from seven donkey foals and plasma was analysed by RIA for IGF-I and C and by a commercial kit for NEFA. IGF-I were significantly higher at 7 (p < 0.05) and at 10 and 14 days (p < 0.01) in comparison to the preceding sampling times, suggesting that like in the horse foals, also in this species in the neonatal period the IGF-I production increase could be responsible for the requested rapid growth. Cortisol was significantly higher (p < 0.01) at 10 min after birth in comparison to all the following sampling times, similarly to the profile reported for the horse full term born foal. The results confirmed that IGF-I, NEFA and C are involved in the process of neonatal adaptation in the donkey foal, with features similar to whose observed for the horse foal.