Leptin, Insulin and Ghrelin Levels in Goat Milk and in Plasma of the Suckling Kids

10 suckling kids (fed goat milk containing 0.53 nmol/l of leptin, 0.30 nmol/l of insulin and l.0l nmol/l of ghrelin) were analysed from the 3“! to the 5th week of age (before the beginning of the weaning period). During the experimental period, body Weight and milk consumption Were recorded. Blood samples were taken Weekly, . before the first meal of the day. Plasma was analyzed for leptin, insulin and ghrelin. As expected, body weight and milk intake increased during the experimental period. Although daily intake of milk hormones and growth factors increased during the period, it was observed that ghrelin did not vary and leptin decreased (P<0.02) in plasma of suckling kids. Contrarily, plasma levels of insulin increased more than 4 times (P<0.0l), with a significant correlation with the quantity of hormone ingested daily (P<0.0l). This latter result is probably due to the increasing amount of milk consumption during the entire period, but it is possible to hypothesize the presence of receptors that facilitate the transfer of milk-born insulin through the gastrointestinal mucosa of the suckling kids. Milk-borne insulin, indeed, plays a crucial role in the functional development of pancreas at the onset of weaning in rats and it has been reported that milk insulin increases plasma insulin levels and this can be a stimulator of pancreatic amylase gene expression just before weaning.