The effect of peripheral administration of ghrelin on the performance of growing geese

Abstract. The purpose of the present study is to investigate the effect of intraperitoneal (IP) injection of ghrelin on goose performance. Hence, forty-eight 28-day-old geese were assigned into three treatments which lasted 40 days. The first intact group included no injection; that is, treatment 1 was characterized by G0; treatment 2, given to the second intact group, was characterized by G50, 50 ng kg⁻¹ ghrelin body weight (BW); and treatment 3, given to the third intact group, was characterized by G100, 100 ng kg⁻¹ ghrelin BW. Ghrelin was injected at the outset of the experimental rearing period (28-day-old birds). Blood samples were taken at two different times: (1) 12 h after the injection and (2) at the end of the rearing period. The effects of the injections were examined and evaluated during two rearing periods (28–48 days old and 48–68 days old). In the second treatment (G50), ghrelin injection caused an increase in the feed intake during the growing period but not the finishing period. Body weight gain and feed conversion ratio (FCR) of the growing period and finishing period did not change following any ghrelin treatments (P > 0.05). Injection of ghrelin at G100 increased breast muscle (pectoral) weight. The results of the present study indicate that ghrelin has a significant impact on feeding regulation and muscle growth at a certain period in geese. Nevertheless, it should be noted that ghrelin may have different effects on feeding of avian species.