Growth hormone-releasing hormone plasmid treatment by electroporation decreases offspring mortality over three pregnancies.

LifeTideSW5 is a growth hormone-releasing hormone (GHRH)-expressing plasmid delivered by intramuscular (IM) electroporation (EP), and the first therapeutic plasmid delivered by this physical method to be approved for use in food animals. Gestating sows (n = 997) were treated once with a single 5-mg GHRH-plasmid by EP or served as controls. Data on offspring from three parities subsequent to treatment were collected. No adverse effects related to treatment were noted. First parity post-treatment offspring from treated sows displayed a 2.93 kg (P < 0.0001) increase in carcass weight (CW), 1.0 mm (P < 0.0001) less back-fat (P2), and a 27.0 g CW/day (P < 0.0001) increase in rate of gain (ROG) compared with controls. An increase of 21.6% was recorded in the number of offspring surviving. In the second and third parities post-treatment, offspring from treated females displayed higher number of born alive and total born number, and lower stillborn rates. Third parity offspring from treated sows displayed a 1.6 kg advantage in CW (P < 0.05), 1.0 mm less P2 (P < 0.05), and a 10.0 g CW/day benefit in ROG. Furthermore, offspring from treated females had a 19.04% lower post-wean loss rate. Overall, plasmid GHRH administration decreased morbidity and mortality in treated females and their offspring over three consecutive pregnancies.