Recombinant porcine somatotropin: an immunotoxicology study

Area of Science:

• Animal Science
• Immunology
• Endocrinology

Background:

• Recombinant porcine somatotropin (rpST) is a growth-promoting agent.
• Understanding its effects on swine immune function is crucial for animal health and welfare.

Purpose of the Study:

• To investigate the impact of varying doses of rpST on diverse immune parameters in pigs.
• To assess the clinical relevance of any observed immune function alterations.

Main Methods:

• Pigs were administered rpST (5, 15, or 25 mg/pig/day) for 57 days.
• Evaluated gross pathology, histopathology, hematology, lymphocyte responses, neutrophil functions, and antibody titers.
• Monitored body weight gain, organ weights, and overall health indicators.

Main Results:

• rpST did not affect most immune variables, including white blood cell counts and neutrophil functions.
• Minor effects included decreased hemoglobin, packed red blood cell volume, and plasma protein levels.
• A transient decrease in IgG response to tetanus toxoid and increased neutrophil random migration were noted.
• Growth rate was reduced at the 15 mg dose, with increased liver/kidney weights and minor kidney vacuolation.

Conclusions:

• rpST treatment showed minimal impact on the majority of swine immune functions.
• Observed alterations in hematological parameters and antibody response were not clinically significant.
• No evidence suggests rpST negatively affects overall swine health or susceptibility to common pathogens.