Veterinarski Glasnik (Jan 2009)
Concentration of cortisol, insulin-like growth factor-I and immunoglobulin G class in blood of neonatal calves of different body mass at birth
Abstract
The objective of this work was to examine whether concentrations of cortisol, insulin-like growth factor-I (IGF-I) and immunoglobulin G class (IgG), in fact blood parameters which are believed to be of extreme importance in the postnatal survival of calves, are dependant on the body mass of calves at birth. Investigations were performed on 12 newborn calves of the Holstein-Friesian breed, placed into two groups on the grounds of their body mass at birth. The first group (n=6) comprised calves whose body mass was more than 35 kg at birth (41.67±3.08 kg), while the second group (n=6) comprised calves whose body mass at birth was less than 35 kg (32.00±3.58 kg). Blood samples were taken immediately preceding the consuming of colostrum, as well as at 32 hours of neonatal life. Cortisol and IGF-I concentrations were determined in blood serum samples taken immediately before colostrum consumption, while IgG concentration was determined in the samples taken 32 hours after the birth of the calves. The cortisol concentration in calves born with a greater body mass (61.51±32.78 nmol/l) was lower (p=0.052) than in calves born with a smaller body mass (94.89±17.74 nmol/l). A significant negative correlation (r= -0.592; p<0.05) was established between the body mass of calves at birth and the cortisol concentration. The IGF-I concentration determined immediately following birth in calves with a greater boy mass at birth (10.17±1.71 nmol/l) was statistically significantly higher (p<0.05) in comparison with calves born with a smaller body mass (7.04±1.15 nmol/l). There was a significant positive correlation (r = 0.519; p<0.10) between the body mass of calves at birth and the IGF-I concentration. Thirty-two hours following birth, the IgG concentration in blood serum of calves born with a bigger body mass (18.72±1.99 g/l) was significantly higher (p<0.05) than in calves born with a smaller body mass (11.68±4.79 g/l). A significant positive correlation was established between the body mass of calves at birth and the IgG concentration determined at 32 hours of neonatal life (r = 0.620; p<0.05). The obtained results point to the conclusion that calves of body mass over 35 kg at birth are better adapted to the conditions of the outer environment in comparison with calves born with a body mass of less than 35 kg. .
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