Skip to main content Accessibility help

The effect of dietary carbohydrate composition on apparent total tract digestibility, feed mean retention time, nitrogen and water balance in horses

  • R. B. Jensen (a1), D. Austbø (a2), K. E. Bach Knudsen (a3) and A.-H. Tauson (a1) (a2)


A total of four diets with different carbohydrate composition were investigated in a 4×4 Latin square design experiment with four Norwegian Coldblooded trotter horses. The objective of the present study was to increase the fermentable fibre content and reduce the starch intake of the total ration obtained by partly substituting mature hay and barley with sugar beet pulp (SBP), a soluble fibre source. The diets investigated were hay only (HAY), hay (85% of dry matter intake (DMI)) and molassed SBP (15% of DMI) (SBP), hay (68% of DMI) and barley (32% of DMI) (BAR), and hay (68% of DMI), barley (26% of DMI) and SBP (6% of DMI) (BAR+SBP). The feeding level was 18.5, 17.3, 15.7 and 15.7 g DM/kg BW per day for the HAY, SBP, BAR and BAR+SBP diets, respectively. Each diet was fed for 18 days followed by 10 days of data collection, where apparent total tract digestibility (ATTD), total mean retention time (TMRT) of ytterbium-labelled hay, water balance, digestible energy (DE) intake and nitrogen balance were measured. An enzymatic chemical dietary fibre (DF) method was used to get detailed information on the composition and ATTD of the fibre fraction. Inclusion of SBP in the diet increased the ATTD of the constituent sugars galactose and arabinose (P<0.01). Feeding the HAY and SBP diets resulted in a lower TMRT owing to a higher DF intake than the BAR and BAR+SBP diets (P<0.01). There was no difference in water intake between HAY and SBP, but faecal dry matter was lower for HAY than the other diets (P=0.017), indicating that water was more tightly bound to fibre in the HAY diet. The diets were iso-energetic and provided enough DE and protein for light to moderate exercise for a 550 kg horse. In conclusion, this study showed that the DF intake had a larger effect on TMRT than partly substituting hay or barley with SBP, and that highly fermentable pectin-rich soluble DF from SBP maintains high nutrient utilization in horses.


Corresponding author



Hide All
Austbø, D and Volden, H 2006. Influence of passage model and caecal cannulation on estimated passage kinetics of roughage and concentrate in the gastrointestinal tract of horses. Livestock Science 100, 3343.
Bach Knudsen, KE 1997. Carbohydrate and lignin contents of plant materials used in animal feeding. Animal Feed Science and Technology 67, 319338.
Bach Knudsen, KE 2001. The nutritional significance of ‘dietary fibre’ analysis. Animal Feed Science and Technology 90, 320.
Brøkner, C, Austbø, D, Næsset, JA, Bach Knudsen, KE and Tauson, AH 2010. The effect of sugar beet pulp on caecal pH in Norwegian cold-blooded trotter horses. In The impact of nutrition on the health and welfare of horses (ed. AD Ellis, AC Longland, M Coenen and N Miraglia), pp. 210212. Wageningen Academic Publishers, Wageningen, The Netherlands.
Brøkner, C, Bach Knudsen, KE, Karaman, I, Eybye, KL and Tauson, AH 2012a. Chemical and physicochemical characterisation of various horse feed ingredients. Animal Feed Science and Technology 177, 8697.
Brøkner, C, Austbø, D, Næsset, JA, Bach Knudsen, KE and Tauson, AH 2012b. Equine pre-caecal and total tract digestibility of individual carbohydrate fractions and their effect on caecal pH response. Archives of Animal Nutrition 66, 490506.
Coenen, M, Kienzle, E, Vervuert, I and Zeyner, A 2011. Recent German developments in the formulation of energy and nutrient requirements in horses and the resulting feeding recommendations. Journal of Equine Veterinary Science 31, 219229.
Connysson, M, Essén-Gustavsson, B, Lindberg, JE and Jansson, A 2010. Effects of feed deprivation on Standardbred horses fed a forage-only diet and a 50:50 forage-oats diet. Equine Veterinary Journal. Supplement 42, 335340.
Coverdale, JA, Moore, JA, Tyler, HD and Miller-Auwerda, PA 2004. Soybean hulls as an alternative feed for horses. Journal of Animal Science 82, 16631668.
Cuddeford, D, Woodhead, A and Muirhead, R 1992. A comparison between the nutritive value of short-cutting cycle, high temperature-dried alfalfa and timothy hay for horses. Equine Veterinary Journal. Supplement 24, 8489.
Drogoul, C, De Fombelle, A and Julliand, V 2001. Feeding and microbial disorders in horses: 2: Effect of three hay:grain ratios on digesta passage rate and digestibility in ponies. Journal of Equine Veterinary Science 21, 487491.
Ellis, JM, Hollands, T and Allen, DE 2002. Effect of forage intake on bodyweight and performance. Equine Veterinary Journal. Supplement 34, 6670.
Faichney, GJ and Boston, RC 1985. Movement of water within the body of sheep fed at maintenance under thermoneutral conditions. Australian Journal of Biological Sciences 38, 8594.
Fonnesbeck, PV 1968. Consumption and excretion of water by horses receiving all hay and hay-grain diets. Journal of Animal Science 27, 13501356.
Groenendyk, S, English, PB and Abetz, I 1988. External balance of water and electrolytes in the horse. Equine Veterinary Journal. Supplement 20, 189193.
Harris, P 2009. Feeding management of elite endurance horses. Veterinary Clinics of North America: Equine Practice 25, 137153.
Hudson, JM, Cohen, ND, Gibbs, PG and Thompson, JA 2001. Feeding practices associated with colic in horses. Journal of the American Veterinary Medical Association 219, 14191425.
Jansson, A and Lindberg, JE 2012. A forage-only diet alters the metabolic response of horses in training. Animal 6, 19391946.
Julliand, V, De Fombelle, A and Varloud, M 2006. Starch digestion in horses: the impact of feed processing. Livestock Science 100, 4452.
Karlsson, CP, Jansson, A, Essén-Gustavsson, B and Lindberg, JE 2002. Effect of molassed sugar beet pulp on nutrient utilisation and metabolic parameters during exercise. Equine Veterinary Journal. Supplement 34, 4449.
Larsson, K and Bengtsson, S 1983. Bestämning av lättilgängeliga kolhydrater i växtmaterial [Determination of readily available carbohydrates in plant materials]. Methods Report No. 22, National Laboratory of Agricultural Chemistry, Uppsala, Sweden.
Luthersson, N, Nielsen, KH, Harris, P and Parkin, TDH 2009. Risk factors associated with equine gastric ulceration syndrome (EGUS) in 201 horses in Denmark. Equine Veterinary Journal. Supplement 41, 625630.
Meyer, H 1987. Nutrition of the equine athlete. In Equine exercise physiology 2 (ed. JR Gillespie and NE Robinson), pp. 644673. ICEEP Publications, Davis, CA, USA.
Moore, JA, Pond, KR, Poore, MH and Goodwin, TG 1992. Influence of model and marker on digesta kinetic estimates for sheep. Journal of Animal Science 70, 35283540.
Moore-Colyer, MJS, Morrow, HJ and Longland, AC 2003. Mathematical modelling of digesta passage rate, mean retention time and in vivo apparent digestibility of two different lengths of hay and big-bale grass silage in ponies. The British Journal of Nutrition 90, 109118.
Murray, JA, Longland, A, Hastie, PM, Moore-Colyer, M and Dunnett, C 2008. The nutritive value of sugar beet pulp-substituted lucerne for equids. Animal Feed Science and Technology 140, 110124.
Murray, JA, Sanderson, R, Longland, AC, Moore-Colyer, MJS, Hastie, PM and Dunnett, C 2009. Assessment of mathematical models to describe the rate of passage of enzyme-treated or sugar beet pulp-substituted lucerne silage in equids. Animal Feed Science and Technology 154, 228240.
NRC 2007. Nutrient requirements of horses, 6th edition The National Academies Press, Washington, DC, USA.
Pagan, JD, Harris, P, Brewster-Barnes, T, Duren, SE and Jackson, SG 1998. Exercise affects digestibility and rate of passage of all-forage and mixed diets in Thoroughbred horses. The Journal of Nutrition 128, 2704S2707S.
Pond, KR, Ellis, WC, Matis, JH, Ferreiro, HM and Sutton, JD 1988. Compartment models for estimating attributes of digesta flow in cattle. The British Journal of Nutrition 60, 571595.
Redbo, I, Redbo-Torstensson, P, Ödberg, FO, Hedendahl, A and Holm, J 1998. Factors affecting behavioural disturbances in race-horses. Animal Science 66, 475481.
Ringmark, S, Roepstorff, L, Essén-Gustavsson, B, Revold, T, Lindholm, A, Hedenström, U, Rundgren, M, Ögren, G and Jansson, A 2013. Growth, training response and health in Standardbred yearlings fed a forage-only diet. Animal 7, 746753.
Rosenfeld, I, Austbø, D and Volden, H 2006. Models for estimating digesta passage kinetics in the gastrointestinal tract of the horse. Journal of Animal Science 84, 33213328.
Serena, A and Bach Knudsen, KE 2007. Chemical and physicochemical characterisation of co-products from the vegetable food and agro industries. Animal Feed Science and Technology 139, 109124.
Siddons, RC, Paradine, J, Beever, DE and Cornell, PR 1985. Ytterbium acetate as a particulate-phase digesta-flow marker. The British Journal of Nutrition 54, 509519.
Theander, O, Åman, P, Westerlund, E and Graham, H 1994. Enzymatic/chemical analysis of dietary fiber. Journal of AOAC International 77, 703709.
Van Soest, PJ, Robertson, JB and Lewis, BA 1991. Methods for dietary fiber, neutral detergent fiber, and nonstarch polysaccharides in relation to animal nutrition. Journal of Dairy Science 74, 35833597.
Van Weyenberg, S, Sales, J and Janssens, GPJ 2006. Passage rate of digesta through the equine gastrointestinal tract: a review. Livestock Science 99, 312.
Vermorel, M and Martin-Rosset, W 1997. Concepts, scientific bases, structure and validation of the French horse net energy system (UFC). Livestock Production Science 47, 261275.
Warren, LK, Lawrence, LM, Brewster-Barnes, T and Powell, DM 1999. The effect of dietary fibre on hydration status after dehydration with frusemide. Equine Veterinary Journal. Supplement 31, 508513.
Woodward, AD, Nielsen, BD, Liesman, J, Lavin, T and Trottier, NL 2011. Protein quality and utilization of timothy, oat-supplemented timothy, and alfalfa at differing harvest maturities in exercised Arabian horses. Journal of Animal Science 89, 40814092.
Zeyner, A, Geissler, C and Dittrich, A 2004. Effects of hay intake and feeding sequence on variables in faeces and faecal water (dry matter, pH value, organic acids, ammonia, buffering capacity) of horses. Journal of Animal Physiology and Animal Nutrition 88, 719.


The effect of dietary carbohydrate composition on apparent total tract digestibility, feed mean retention time, nitrogen and water balance in horses

  • R. B. Jensen (a1), D. Austbø (a2), K. E. Bach Knudsen (a3) and A.-H. Tauson (a1) (a2)


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed