this study involved chickens. i think i understand this one a little better than my previous one. as a matter of fact, i think this is more evidence of what i have already heard and found on igf-1lr3. if there are any questions, i will try my best. also, here is the link to the site. it was one study out of many, so scroll down to near the bottom of the page.

Metabolic Responses of the Chicken to an Intravenous Injection of Either Chicken (CIGF-I) or Human Insulin -like Growth Factor-I (hIGF-I)
J. McMurtry, G. Francis, T. Caperna, R. Vasilatos-Younken, R. Rosebrough, D. Brocht

USDA, ARS, Growth Biology Lab, Beltsville, MD, USA
(FAX: 301-504-8803; E-mail:

The purpose of this study was to compare the metabolic and endocrine responses of male broiler chickens to an intravenous injection of either cIGFI, hIGFI or cIGFILR3 (an IGFI analogue). At 5 weeks of age, chickens were surgically implanted with a jugular cannula. Following an 8 h fast, equimolar amounts of cIGFI, hIGFI and cIGFILR3 (100, 102 and 126 mg/kg bw, respectively) were infused. Control birds were infused with an equal volume of saline. Plasma samples were collected at selected intervals pre and postinfusion and analyzed for various hormonal and metabolite parameters as well as insulinlike growth factor binding protein (IGFBP) activity. Similar hypoglycemic responses (50%) were induced by cIGFI and hIGFI, and to a lesser extent (30%) by LR3. A concomitant decline in insulin concentrations was noted. GH levels were differentially affected following growth factor treatment in that cIGFI and hIGFI were similarly depressed, while only minor decreases in GH were observed following LR3 treatment. Regardless of treatment, plasma T4 and T3 declined during the sampling period. Significant increases in plasma glucagon and free fatty acid concentrations were observed, while triglyceride levels were unaffected. Changes in IGFBP activity were noted. Similar metabolic and endocrine responses were elicited by cIGFI and hIGFI, while less dramatic changes in these parameters were induced by cIGFI LR3.