INS and fetal growth restriction: Glucose‐potentiated arginine‐stimulated insulin concentrations were similar among experimental groups (mean values for controls 31.8 ± 5.2 μg l−1, IUGR lambs 30.7 ± 4.5 μg l−1, IUGR‐AR lambs 27.4 ± 5.3 μg l−1).