The neonatal
leptin surge is important for hypothalamic development, feed intake regulation, and long-term metabolic control. In sheep, the
leptin surge is eliminated with maternal
overnutrition and an elevated dam body condition score (BCS), but this has not been assessed in dairy cattle. The aim of this study was to characterize the neonatal profile of
leptin,
cortisol and other key metabolites in calves born to Holstein cows with a range of BCS. Dam BCS was determined 21 d before expected parturition. Blood was collected from calves within 4 h of birth (d 0), and on days 1, 3, 5, and 7. Serum was analyzed for concentrations of
leptin,
cortisol, blood
urea nitrogen, β-hydroxybutyrate (BHB),
free fatty acids (FFA),
triglycerides, and total
protein (TP). Statistical analysis was performed separately for calves sired by Holstein (HOL) or Angus (HOL-ANG) bulls.
Leptin tended to decrease after birth in HOL calves, but there was no evidence of an association between
leptin and BCS. For HOL calves, the
cortisol level increased with an increasing dam BCS on day 0 only. Dam BCS was variably associated with the calf BHB and TP levels, depending on the sire breed and day of age. Further investigation is required to elucidate the impacts of maternal dietary and energy status during gestation on offspring metabolism and performance, in addition to the potential impact of the absence of a
leptin surge on long-term feed intake regulation in dairy cattle.