Submitted to: Midwestern Section of the American Society of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: November 15, 2003
Publication Date: March 15, 2004
Citation: Salfen, B.E., Carroll, J.A., Keisler, D. 2004. Effects of exogenous ghrelin on feed intake, weight gain, behavior, and endocrine parameters in weanling pigs [abstract]. Midwestern Section of the American Society of Animal Science Conference. 82(2):89. Technical Abstract: Our objectives were to determine relative gain, feed intake, behavior, and endocrine parameters in weaned pigs receiving exogenous ghrelin. Twenty-four barrows weaned at 18 d of age (d 0 of study), were jugular vein catheterized, weighed, and assigned to either a ghrelin (GR; n=12) or saline injection group (CON; n=12). Initial pig weights were not different between treatments (7.87 +/- 0.39 vs. 7.92 +/- 0.35 kg for GR and CON treatments, respectively). Pig weights and feed intakes were measured once daily throughout the study. Starting on d 1, GR pigs were intravenously injected three times daily for 5 d with 2 ug/kg human ghrelin and CON pigs were similarly injected with saline. Activity observations and blood samples were taken at -15, 0, 15, 30, 60, 90, 120, 240, and 480 min relative to the first injection. Weight gain during the 5 d injection period was greater in the GR-treated compared to CON-treated pigs (0.57 +/- 0.10 vs. 0.21 +/- 0.13 kg, respectively; P < 0.04), however, there was no increase in feed intake. Two observation periods during the experiment showed more pigs in the GR treatment eating during the observation period compared to CON-treated pigs (P < 0.05). The initial injection of exogenous ghrelin elevated serum ghrelin, GH, insulin, and cortisol (P < 0.05). Endogenous serum ghrelin increased from d 1 to 8 of the study in CON animals (P < 0.05). Serum IGF-I initially fell in both treatment groups from d 1 to 2 (P < 0.05), but then increased from d 5 to 8 (P < 0.05). Peripheral concentrations of glucose in the GR-treated pigs were greater on d 2, 3, 7, and 8 than on d 1 (P < 0.05). In both treatment groups, peripheral concentrations of leptin increased from d 7 to 8 and cortisol decreased from d 1 to 5 of the study. These observations provide evidence that ghrelin may positively influence weight gain, while concomitantly increasing GH, insulin, and cortisol secretion in weaned pigs.