Previous studies from our laboratory have demonstrated that administration of a myogenic plasmid that encodes a protease-resistant growth hormone-releasing hormone (HV-GHRH) to pregnant rat dams augmented long-term growth in first-generation progeny. In the present study, gilts were injected /electroporated intramuscularly at day 85 of gestation with 0, 0.1, 0.5, 1, and 5 mg of the HV-GHRH-expressing plasmid. Piglets were weighed and bled periodically from birth to 100 kg. Piglets from gilts treated with 1 and 5 mg of HV-GHRH plasmid were larger at birth and weaning compared to controls. These two groups reached 100 kg 9 days earlier than the other groups. GHRH levels were increased at birth in piglets from treated gilts. IGF-I levels were significantly increased in the 5 mg group beginning at 21 days of age compared with controls. Pituitaries from the 5 mg group contained a significantly increased number of somatotrophs and lactotrophs from birth to 100 kg. This study confirms that enhanced maternal GHRH production results in inter-generational growth augmentation, and that the magnitude of the response is dose dependent. The similarity of the response across species suggests that the effect is likely exerted as a fundamental component of gestational and developmental physiology.