The influence of temperament on cortisol concentration and metabolic profile in Tsigai lambs

The aim of the present study was to investigate the relationships between temperament score and blood cortisol concentration, as well as energy metabolic parameters (glucose, triglyceride, non-esterified fatty acid and cholesterol) in Tsigai lambs during fattening. The temperament of lambs was assessed (scored) by a temperament score test, where the behaviour of animals was evaluated in a 5-score system (1: calm, 5: nervous) while spending 30 sec on the scale during weighing. Based on temperament scoring at the beginning of fattening 7, 6 and 7 lambs were selected according to temperament categories as calm (1 score 1), intermediate (score 3) and nervous lambs (scores 4 and 5), respectively. At this time, our study did not show any correlation between temperament score, blood cortisol concentration and the metabolic profile. However, at the end of fattening, the calmer lambs had lower cortisol concentrations (2.60 nmol/l) compared to the more nervous lambs (8.07 nmol/l). The calm lambs had lower (P<0.05) non-esterified fatty acid (0.37 mmol/l), cholesterol (1.44 mmol/l) and glucose (3.29 mmol/l) and higher triglyceride (0.98 mmol/l) concentrations and daily weight gain (447.45 g/day) compared to the excitable ones (0.81, 1.86, 4.14, 0.57 mmol/l and 366.84 g/day). These data prove that an increased temperament score, through the higher cortisol concentration, has a great effect on the lambs' energy metabolic profile, which influences the fattening performance.