The effect of oral L-carnitine supplementation on the muscle and plasma concentrations in the Thoroughbred horse.

This research study evaluated the impact of orally given L-carnitine on plasma, muscle, and urine concentrations in Thoroughbred horses over a period of 58 days.

Methodology

• The research involved administering L-carnitine orally to Thoroughbred horses for a duration of 58 days. The given quantity ranged from 10-60 grams per day, distributed in 2-3 doses. The doses were well tolerated by the horses with no harmful side effects reported.

Findings

• Oral administration of 10g of L-carnitine significantly increased the plasma-free carnitine concentration from 21.2 to 31.8 mumol/l, 7 hours post administration.
• When the dosage was increased to two doses of 30g each, the mean plasma-free carnitine concentration increased to 36.5 mumol/l.
• Along with the increased carnitine levels, plasma acetylcarnitine also saw a rise from approximately 1 to 5.5 mumol/l (7 hr post) on 2 x 30 g/day.
• However, muscle total carnitine concentration remained unaffected over the course of 58 days.

Observations

• The urinary output varied between 3.5-7.5% of the administered carnitine, indicating a low rate of intestinal absorption.
• This suggests that the amount of L-carnitine absorbed from the digestive tract into the horse’s system was minimal. The majority of the administered L-carnitine was likely excreted without being metabolized by the horse’s body.

Conclusion

• This study has given valuable insights into how orally administered L-carnitine affects plasma, muscle, and urine concentrations in Thoroughbred horses.
• While the supplement had a noticeable effect on plasma carnitine levels, it didn’t have a significant impact on muscle carnitine content over the study period. Also, a low absorption rate was noted, as observed from the lower-than-expected urinary output.
• This calls for further research into alternate methods of L-carnitine administration or modifications in dosage to optimize its absorption and effectiveness.