Growth Hormone–releasing Hormone Plasmid Treatment by Electroporation Decreases Offspring Mortality Over Three Pregnancies

Abstract

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.

Effects of administration of two growth hormone–releasing hormone plasmids to gilts on sow and litter performance for the subsequent three gestations

“…The gilts used in the present study were genetically similar to pigs used in a previous study 7 in Australia. Gilts were tested prior to entry into the study and routinely during the study for swine influenza virus (H1N1 and H3N2), porcine reproductive and respiratory syndrome virus, and Mycoplasma hyopneumoniae.…”

“…A single treatment of pregnant gilts or sows reduces the perinatal mortality rate and improves production performance during 3 consecutive gestations. 7 Furthermore, in a study 8 in which baby pigs were cross-fostered, it was found that the improved preweaning growth of offspring born to GHRH plasmid-treated sows was attributable to improved maternal performance.…”

“…7 The purpose of the study reported here was to evaluate the ability of a novel optimized plasmid to achieve a similar response when administered at a lower dose than that of the commercial plasmid. The success of an optimized plasmid could dramatically improve the feasibility for the use of plasmid-based DNA treatments in agricultural animals, companion animals, and humans.…”

Antiparasitic DNA vaccines in 21st century

“…At the end of XX century development of molecular biology and biotechnology raised hopes for a quick development of anti-parasitic vaccine industry thanks to DNA (cDNA) based vaccines (Wolff et al 1990). However, despite that numerous experimental studies have been conducted since Wollff's publication, to date there are only few DNA vaccines that have been approved for veterinary use (Davidson et al 2005;Garver et al 2005;Bergman et al 2006;Person et al 2008). Moreover, only two of them are prophylactic vaccines; one to prevent West Nile Virus infections in horses (Davidson et al 2005) and the second to stimulate innate and adaptive immune responses of salmons to infections with haematopoietic necrosis virus (Garver et al 2005).…”

DNA Vaccines: How Much Have We Accomplished In The Last 25 Years?

“…A veterinary DNA vaccine to protect horses against West Nile virus was first licensed in 2005 by the FDA [146]. In 2008, the Australian Pesticides and Veterinary Medicines Authority approved a DNA-based growth hormone therapy, delivered using electroporation (EP), for use in swines [147]. In total, four animal DNA vaccines were approved for the vaccination of horses, salmon, pigs and dogs (Table 4).…”