The effects of bovine recombinant growth hormone administration on insulin-like growth factor-I and the haemopoietic system in thoroughbred geldings.

The research study investigates the impacts of bovine growth hormones administered to Thoroughbred geldings, discovering such process prompts a surge in insulin-like growth factor-I and alters blood cell indices. This could offer therapeutic benefits when administered in specific doses.

Objectives and Methods

• The study aimed to analyze how bovine growth hormone (rbGH), when intramuscularly administered, affected the insulin-like growth factor-I (IGF-I) and the haemopoietic system of Thoroughbred geldings.
• An insulin-like growth factor binding protein (IGFBP)-blocked radioimmunoassay, which was modified and validated for the measurement of IGF-I in equine blood plasma, was used.
• Through a 48-hour period, baseline values for IGF-I and blood components were determined before introducing a single dose of either 5, 10, or 50 micrograms per kilogram of rbGH.

Findings

• The levels of insulin-like growth factor-I increased in correspondence with the doses, peaking between the 12 to 24-hour mark.
• The highest dose (50 micrograms per kilogram) yielded the highest IGF-I response which saw a 90.2±10.8% increase at the 24th hour.
• All three doses prompted an increase in the white blood cell count, with the count peaking at the 12th hour mark when the rbGH dose was at its highest.
• Notably, at the 24th hour mark, the haemoglobin significantly increased, specifically for the 10 micrograms per kilogram and the 50 micrograms per kilogram doses, whereas the red blood cell count was unaffected by the rbGH doses.

Implications

• The findings indicated that rbGH has a biological effect on horses and could bring therapeutic benefits.
• Dosage plays a critical role, and a mininum of 10 micrograms per kilogram is recommended for potential therapeutic use in horses.