Effects of Uphill Exercise on Digestible Energy Intake and Energy Expenditure during Exercise in Yearling Horses

  • Matsui, A. (Breeding and Training Research Unit, Hidaka Yearling Training Farm, Japan Racing Association) ;
  • Katsuki, R. (Equine Research Institue, Japan Racing Association) ;
  • Fujikawa, H. (Equine Research Institue, Japan Racing Association) ;
  • Kai, M. (Equine Research Institue, Japan Racing Association) ;
  • Kubo, K. (Equine Research Institue, Japan Racing Association) ;
  • Hiraga, A. (Equine Research Institue, Japan Racing Association) ;
  • Asai, Y. (Breeding and Training Research Unit, Hidaka Yearling Training Farm, Japan Racing Association)
  • Received : 2003.07.31
  • Accepted : 2004.01.26
  • Published : 2004.07.01


The objectives of this study were to evaluate the digestible energy intake and energy expenditure in yearling horses on different training protocols (uphill- and level-track exercise training protocols). Twenty-four thoroughbred yearlings (12 males and 12 females, aged 27.0$\pm$0.9 months) were divided into two groups based on their training on two different tracks: the uphill (with a gradient of about 3%) training group (uphill training) and the level training group (level training). The digestible energy (DE) intake and energy expenditure (EE) during exercise were measured in both the groups. It was found that the DE intake in the uphill training and the level training groups was 5.1$\pm$3.1 and 36.9$\pm$4.8 Mcal/day, respectively. The EE during exercise in the two groups was 3.05$\pm$0.51 and 2.07 $\pm$0.56 Mcal, respectively. Thus, there was a significant difference in the EE (p<0.05), but not in the DE intake between the animals of the two training groups. The EE for a given intensity of exercise was greater in the uphill training group than in the level training group, but the DE intake was not affected by the exercise intensity. The DE intake was not generally affected by the intensity of exercise in this study, but a daily negative gain of body weight was observed in the uphill training group, particularly in the females. Thus, the energy requirement may be higher in yearlings undergoing uphill training than in those undergoing level training.


Digestible Energy;Energy Expenditure;Exercise;Horse


  1. Brouns, F. and E. Becker. 1993. Is the gut and athletic organ? Digestion, absorption and exercise. Sports Medicine. 15:242-257.
  2. Dauncei, M. J. and WPT. James. 1979. Assessment of the heartrate method for determining energy expenditure in man, using a whole-body calorrimeter. Br. J. Nutr. 42:1-13.
  3. Devienne, M. F. and C. Y. Guezennec. 2000. Energy expenditure of horse riding. Eur. J. Appl. Physiol. 82:499-503.
  4. Hebestreit, H., O. Bar-Or. C. McKinty, M. Riddell and P. Zehr. 1995. Climate-related corrections for improved estimation of energy expenditure from heart rate in children. J. Appl. Physiol. 79:47-54.
  5. Kalkwarf, H. J., J. D. Hass, A. Z. Belk, R. C. Roach and D. A. Roe. 1989. Accuracy of heart-rate monitoring and activity daiaries for estimating energy expenditure. Am. J. Clin. Nutr. 49:37-43.
  6. National Research Council. 1989. Nutrient Requirements of Horses. 5th. Ed. National Academy of Science, Washington DC p. 48.
  7. Orton, R. K., I. D. Hume and R. A. Leng. 1985. Effects of exercise and level of digestive function in horses. Eq. Vet. J. 17:386-390.
  8. Pagan, R. J., D. R. Hodgson, W. M. Bayly and P. D. Gollnick. 1990. Kinetics of VO2 and VCO2 in the horse and comparison of five methods- for determination of maximum oxygen uptake. Equine Vet. J. Suppl. 9:39-42.
  9. Harris, P. A., D. H. Snow, T. R. Great and P. D. Rossdale. 1990. Some factors influencing plasma AST/CK activities in thoroughbred racehorses. Equine Vet. J. Suppl. 9:66-71.
  10. Sutton, E. L., J. P. Bowland and J. F. McCarthy. 1977. Studies with horses comparing 4 N-HCl insoluble ash as an index material with total fecal collection in the determination of apparent digestibilities. Can. J. Anim. Sci. 57:543-549.
  11. Jones, J. H., K. E. Longworth, A. Lindholm, K. E. Conley, R. H. Karas, S. R. Kayar and .C. R.Taylor. 1989. Oxygen transport during exercise in large mammals. I. Adaptive variation in oxygen demand. J. Appl. Physiol. 67:862-870.
  12. Asai, Y., A. Matsui, T. Osawa, M. Kawai and S. Kondo. 1999. Digestible energy expenditure in grazing activity horses. Equine Vet. J. Suppl. 30:490-492.
  13. Butler, P. J., A. J. Woaks, L. S. Anderson, C. A. Robert and D. J. Marlin. 1993. Stride length and respiratory tidal volume in exercising Thoroughbred horse. Respir. Physiol. 93:51-56.
  14. Vogtmann, H., H. P. Pfirter and A. L. Prabucki. 1975. A new method of determining metabolisability of energy and digestibility of fatty acid in broiler diets. Br. Pou. Sci. 16:531-534.
  15. AOAC. 1999. Official Methods of Analysis (16th Ed.). Association of Official Analytical Chemists, Arlington, Virginia.
  16. Ceesay, S. M., A. M. Prentice, K. C. Day, P. R. Mufgatroyd, G. R. Goldberg, W. Scott and G.. B. Spurr. 1989. The use of heart rate monitoring in the estimation of energy expenditure, a validation study using indirect whole-body calofimetry. Br. J. Nutr. 61:175-186.
  17. Fonnesbeck, P. V. 1981. Estimating digestible energy and TDN for horses with chemical analysis of feeds. 290:241-242.
  18. Li, R., P. Deurenberg and J. G. Hautvast. 1993. A critical evaluation of heart rate monitoring to assess energy expenditure in individuals. Am. J. Clin. Nutr. 58:602-607.
  19. Brosh, A., Y. Aharoni, A. A. Degen, D. Wright and B. Young. 1998. Estimation of energy expenditure from heart rate measurements in cattle maintained under different conditions. J. Anim. Sci. 76:3054-3064.
  20. Ott, E. A., R. L. Asquith and J. P. Feaster. 1981. Lysine supplementation of diets for yearling horses. J. Anim. Sci. 53:1496-1503.
  21. Katsuki, R., Y. Asai and H. Fuhikawa. 1998. Effect of exercise on the apparent energy digestibility of timothy and alfalfa in thoroughbred horses. J. Equine Sci. 9:29-31.
  22. Hiraga, A., M. Kai, K. Kubo, Y. Yammaya and E. K. Erickson. 1995. The effect of incline on cardiopulmonary function during exercise in the horse. J. Equine Sci. 2:55-60.
  23. Frape, D. L. 1988. Dietary requirements and athletic performance of horse. Equine Vet. J. 20:163-172.
  24. Birks, E. K., J. H. Jones and J. D. Berry. 1991. Plasma lactate kinetics in xercising horse. In: Equine Exercise Physiology 3, (Ed. S. G. B. P. A. Lindholm and L. B. Jeffcott), Almqvist and Wikesell Tryckeri, Uppsala. pp. 170-187.
  25. Fan, Y. K., J. C. Hsu, H. C. Peh, C. L. Tsang, S. P. Cheng, S. C. Chiu and J. C. Ju. 2002. The Effects of Endurance Training on the Hemogram of the Horse. Asian-Aust. J. Anim. Sci. 15:1348-1353.
  26. Thornton, J., J. Pagan and S. Persson. 1987. The oxygen cost of weight loading and inclined treadmill exercise in the horse. p. 206-215. In: Equine Exercise Physiology 2. (Ed. J. R. Gillespie and N. E. Robinson) ICEEP Publication, Davis, California.
  27. Van Soest, P. J. 1963. Use of detergents in the analysis fibrous feeds II. A rapid method for the determination of fiber and ligunine. J. Ass. Agric. Chem. 6:829-835.

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