Effect of in Ovo Administration of Exogenous Ghrelin on Weight of Internal Organs in Newly-hatched Chicks

The present study was performed for investigation on possible effects of exogenous ghrelin (GH-releasing peptide) on liver, heart, gizzard (proventriculus+gizzard), intestine and breast muscle weights. One hundred fertilized eggs were divided into two groups includes control or group1 (without any in ovo ghrelin administration) and group2 (in ovo administration of 100ng/egg ghrelin at day-5). In ovo injection process was done by 22g needles and infusion of 0.5 ml solution in albumen. All of eggs were incubated under normal hatchery conditions. At end of incubation, ten chicks from each group were decollated and internal organs were separated and weighed. The results had shown that exogenous ghrelin only had significant effect on intestine weight (group1: 2.05g and group2: 2.30g) (P<0.01) and minor positive effect on gizzard weight (group1:2.20g and group2: 2.26), too. There was not any significant positive effect on liver, heart and breast muscle weights via in ovo injection of ghrelin. With attention to ghrelin’s gastrointestinal origin (synthesis in gastrointestinal cells) and physiological potential for GH releasing, so its effect on gastrointestinal organs of chicken (such as gizzard and intestine) may be because of its specific regulatory roles in development of these organs during embryonic life. Present findings are in agreement with past findings about effects of in ovo injected ghrelin on chicken intestinal enzymes activity. As conclusion, in ovo ghrelin can affect embryonic development of gastrointestinal organs and their weight gain in chicks.