The variation of leptin plasma concentration in growing buffaloes.

Leptin, a hormone mainly secreted by adipose tissue, is involved in the regulation of food intake, energy expenditure and whole-body energy balance. The aim of this study was to evaluate whether leptin concentration changes in growing buffaloes. The correlation between plasma leptin level and some haematic parameters as well as between leptin level and some growing indices was also analysed. Plasma level of glucagone, insulin, glucose, NEFA and 3-hydroxybutyrate were measured. Liveweight, rump area, compactness index, bodily index, tronco-thoracic index and average daily gain were chosen as somatic parameters. Blood samples were collected at 30 days intervals for ten months from 20 young growing buffaloes, starting from animals 130 days old. We found that plasma leptin level increased with weight gain. In particular, plasma leptin level decreased between the 7th and 9th month of age, anddramatically increased between the 10th and the 12th month of age. Plasma insulin and somatic parameters were positively correlated with leptin level while glucose and NEFA were negatively correlated with leptin plasma level. These results suggest that leptin might play a central role in the regulation of glycaemia and fat mobilization during growth in buffaloes.