The effect of time of feeding on plasma amino acids during exercise and recovery in horses.
Abstract: Feeding management in horses suggests feeding horses in advance of exercise, particularly the grain portion of the diet. Plasma amino acids () peak at 3 to 6 h postfeeding depending on the AA. The timeframe between feeding and exercise may affect the availability of AA during and after exercise. The purpose of this study was to observe the differences in plasma AA in horses fed prior to exercise or after exercise. Eight light type horses were fed a diet with adequate protein and AA for horses in light to moderate exercise. After an adjustment period, horses completed a standardized exercise test (). Relative to the SET, horses were fed either 2 h prior ( horses) to the SET, 1 h after completing the SET ( horses), or horses remained fasted throughout the sampling period ( horses). Plasma was drawn prior to exercise, at the peak of exercise as well as at 1, 2, 4, and 7 h postexercise. Plasma was analyzed for AA, glucose, lactate, creatinine, creatine kinase, ammonia, urea-N, and 3-methylhistdine. After completion of the SET and sampling period, horses entered a 1-wk recovery period, which was followed by another SET. The protocol repeated until horses rotated through all feeding protocols in the study (three SETs). The majority of the plasma AA were elevated in PRE horses compared with POST horses prior to the SET until 2 h postexercise where POST horses' plasma AA concentrations became elevated and remained elevated until the end of the sampling period. In that same time frame, plasma AA for the PRE group decreased out to the end of the sampling period. The elevation of plasma AA in POST horses would be expected as they were fed at 1 h postexercise, whereas PRE horses were reaching a 4 h postfeeding time frame at this point. This elevation was not observed for plasma concentrations of isoleucine, leucine, methionine, and histidine. Concentrations of these AA initially were greater for POST horses in the postexercise period; however, they declined more rapidly than the other AA. The rapid decrease of some of the plasma AA concentrations may suggest uptake by muscle for recovery. This in conjunction with a decrease in plasma creatine kinase concentrations for POST horses suggests that feeding postexercise may facilitate better muscle protein balance (synthesis vs. breakdown) in the recovery period following exercise.
© The Author(s) 2021. Published by Oxford University Press on behalf of the American Society of Animal Science.
Publication Date: 2021-03-23 PubMed ID: 34179699PubMed Central: PMC8221455DOI: 10.1093/tas/txab045Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
The research is about the effects of feeding times on the plasma amino acid levels during and after exercise in horses. It investigates whether feeding horses before or after exercising impacts the availability of amino acids and the recovery process. The study concludes that feeding after exercise could facilitate a better muscle protein balance through increased amino acid uptake and decreased creatine kinase concentration.
Objective of the Study
- The study’s primary aim is to determine how the timing of feeding horses affects the plasma amino acid (AA) availability during and after exercise. It compares the plasma AA levels of the horses fed before exercise, after exercise, and those that fasted throughout the study period.
Study Design and Methodology
- The study involved the use of eight light-type horses on a diet rich in proteins and amino acids suitable for horses engaged in light to moderate level exercises.
- After a period of adjustment, the horses participated in a Standardized Exercise Test (SET).
- The horses were fed according to three different feeding schedules relative to the exercise. The groupings were; feeding 2 hours before the SET, feeding 1 hour after the SET, and horses that fasted throughout the experiment.
- Plasma was drawn from the horses and analyzed at different intervals; before exercise, at the peak of exercise, and at intervals of 1, 2, 4, and 7 hours post-exercise.
- Plasma was tested for AA, glucose, lactate, creatinine, creatine kinase, ammonia, urea-N and 3-methylhistdine.
Key Findings
- The majority of the plasma AA were found to be higher in the horses fed before (PRE) exercise, compared with those fed after (POST) exercise from pre-exercise time until 2 hours post-exercise.
- However, starting from 2 hours post-exercise, the levels of plasma AA in POST horses (those fed after exercise) became and remained higher until the end of the sampling period. At the same time, the PRE group’s plasma AA levels steadily decreased.
- The elevated plasma AA for the POST group was as expected. A decrease in plasma creatine kinase in the POST group also suggested that feeding after exercise could facilitate better muscle protein balance in the recovery period after exercise.
- The decrease in plasma Isoleucine, Leucine, Methionine, and Histidine levels in POST horses after the initial surge suggested the uptake of these amino acids by the muscles for recovery.
Implications and Conclusion
- The research showed that the timing of feeding relative to exercise impacts the plasma amino acid availability in the horses.
- This study suggests that feeding horses post-exercise could promote better muscle recovery than when horses are fed pre-exercise. The changes in plasma AA and creatine kinase concentrations observed support this conclusion.
Cite This Article
APA
Graham-Thiers PM, Bowen LK.
(2021).
The effect of time of feeding on plasma amino acids during exercise and recovery in horses.
Transl Anim Sci, 5(2), txab045.
https://doi.org/10.1093/tas/txab045 Publication
Researcher Affiliations
- Equine Studies Department, Emory & Henry College, Emory, VA 24327, USA.
- Equine Studies Department, Emory & Henry College, Emory, VA 24327, USA.
References
This article includes 20 references
- Bröer S. Amino acid transport across mammalian intestinal and renal epithelia.. Physiol Rev 2008 Jan;88(1):249-86.
- Clark LL, Roberts MC, Argenzio RA. Feeding and digestive problems in horses. Vet Clinics of North America: Equine Practice Vo. 6(2):433–449.
- Graham-Thiers PM, Bowen LK. Effect of protein source on nitrogen balance and plasma amino acids in exercising horses.. J Anim Sci 2011 Mar;89(3):729-35.
- Graham-Thiers PM, Wilson JA, Haught J, Goldberg M. Relationships between dietary, plasma and muscle amino acids in horses. Prof. Anim. Sci. 28(3):351–357.
- Greer BK, Woodard JL, White JP, Arguello EM, Haymes EM. Branched-chain amino acid supplementation and indicators of muscle damage after endurance exercise.. Int J Sport Nutr Exerc Metab 2007 Dec;17(6):595-607.
- Hiney KM, Potter GD. A review of recent research on nutrition and metabolism in the athletic horse.. Nutr Res Rev 1996 Jan;9(1):149-73.
- Johnson RJ, Hart JW. Influence of feeding and fasting on plasma free amino acids in the equine.. J Anim Sci 1974 Apr;38(4):790-4.
- Makai K, Takahashi T, Eto D, Ohmura H, Tsubone H, Hiraga A. Heart rates and blood lactate response in Thoroughbred horses during a race. J. Eq. Sci. 18:153–160.
- Matsui A, Ohmura H, Asai Y, Takahashi T, Hiraga A, Okamura K, Tokimura H, Sugino T, Obitsu T, Taniguchi K. Effect of amino acid and glucose administration following exercise on the turnover of muscle protein in the hindlimb femoral region of thoroughbreds.. Equine Vet J Suppl 2006 Aug;(36):611-6.
- Miller-Graber P, Lawrence L, Foreman J, Bump K, Fisher M, Kurcz E. Effect of dietary protein level on nitrogen metabolites in exercised Quarter Horses. Equine Ex. Phys. 3:305–314.
- Nostell KE, Essén-Gustavsson B, Bröjer JT. Repeated post-exercise administration with a mixture of leucine and glucose alters the plasma amino acid profile in Standardbred trotters.. Acta Vet Scand 2012 Feb 1;54(1):7.
- NRC. Nutrient requirements of swine, 10th ed. Washington (DC): National Academy of Science.
- NRC. Nutrient requirements of horses, 6th ed. Washington (DC): National Academy of Science.
- Poso AR, Essen-Gustavsson B, Lindholm A, Persson SGB. Exercise-induced changes in muscle and plasma amino acid levels in the Standardbred horse. Equine Ex. Phys. 3:2020–208.
- Russell MA, Rodiek AV, Lawrence LM. Effect of meal schedules and fasting on selected plasma free amino acids in horses.. J Anim Sci 1986 Nov;63(5):1428-31.
- Urschel KL, Geor RJ, Waterfall HL, Shoveller AK, McCutcheon LJ. Effects of leucine or whey protein addition to an oral glucose solution on serum insulin, plasma glucose and plasma amino acid responses in horses at rest and following exercise.. Equine Vet J Suppl 2010 Nov;(38):347-54.
- van den Hoven R, Bauer A, Hackl S, Zickl M, Spona J, Zentek J. Changes in intramuscular amino acid levels in submaximally exercised horses - a pilot study.. J Anim Physiol Anim Nutr (Berl) 2010 Aug 1;94(4):455-64.
- van den Hoven R, Bauer A, Hackl S, Zickl M, Spona J, Zentek J. A preliminary study on the changes in some potential markers of muscle-cell degradation in sub-maximally exercised horses supplemented with a protein and amino acid mixture.. J Anim Physiol Anim Nutr (Berl) 2011 Oct;95(5):664-75.
- Wolfe RR. Protein supplements and exercise.. Am J Clin Nutr 2000 Aug;72(2 Suppl):551S-7S.
- Woodward AD, Holcombe SJ, Steibel JP, Staniar WB, Colvin C, Trottier NL. Cationic and neutral amino acid transporter transcript abundances are differentially expressed in the equine intestinal tract.. J Anim Sci 2010 Mar;88(3):1028-33.
Citations
This article has been cited 0 times.Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
