Full Length Research Paper

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

Mohammad Shamsollahi¹*, Homayun Khazali², Armin Towhidi³, Mehdi Zhandi³, Mohammad Ali Emami-Mibodi⁴, Yahya Mohammadi⁵ and Mansour Ahmadi¹

¹Department of Animal Science, Faculty of Agriculture, Islamic Azad University, Ilam branch, Ilam, Iran.

²Department of Biology, Faculty of Basic Science, University of Shaheid Beheshti, Tehran, Iran.

³Department of Animal Science, Faculty of Agronomy and Animal Science, University of Tehran, Karaj, Iran.

⁴Agriculture and Natural Resources Research Institute, Yazs, Iran.

⁵Department of Animal Science, University of Ilam, Ilam, Iran.

*Corresponding author. E-mail: shamsollahim@yahoo.com. Tel: 0098-918-3435269. Fax: 0098-841-2228074.

Accepted 12 September, 2008

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 the Saanen 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.

Key word: Galanin, growth hormone, thyroxine, triiodothyronine, Saanen goats.