Effect of intravenous injection of galanin on plasma concentrations of growth hormone, thyroid hormones and milk production in the Saanen goat

The goal of this study was to determine whether intravenously galanin injection effect on plasma concentrations of growth hormone (GH), thyroxine (T4), triiodothyronine (T3) and milk production in theSaanen goats. Fifteen Saanen goats were randomly divided into 5 groups (n = 3 in each group). Each group received daily injection of 0, 0.2, 0.4, 0.8 and 1.6 g galanin/Kg for 10 days (period of injection).Blood and milk samples were collected daily on d-2 to d-1 (before treatment), d0 to d10 (during treatment), and d11 to d12 (after treatment) each morning. Injection of galanin significantly (P < 0.05)increased plasma concentrations of GH. Also, galanin decreased plasma concentrations of T3 and T4 throughout the experiment period, while it had no significant effect on milk production. The result of this study indicated that galanin may increase the plasma concentration of GH, and decrease the plasma concentration of T3 and T4, but fail to alter milk production in the Saanen goats