Effects of feeding frequency and voluntary salt intake on fluid and electrolyte regulation in athletic horses.
Abstract: The effect of feeding frequency and voluntary sodium intake (VSI) on fluid shifts and plasma aldosterone concentration (PAC) were studied at rest and after exercise in six athletic horses. The horses were fed twice a day (2TD) and six times a day (6TD) for 25 days for each protocol, according to a changeover design. VSI was measured by weighing each horse's salt block daily. Feeding 2TD or 6TD caused no major alterations in fluid shifts, but in the 2TD treatment there was a postprandial increase in plasma protein concentration and osmolality that lasted <1 h. PAC and VSI were not affected by feeding frequency. VSI ranged from 0 to 62 mg x kg body weight-1 x day-1 and caused significant alterations in PAC. At VSI <26 mg x kg body weight-1 x day-1, a diurnal rhythm for PAC was noted. Water intake, fecal concentrations of sodium and potassium, and packed cell volume during exercise were influenced by VSI. The response to exercise did not differ between treatments. In conclusion, VSI, but not feeding frequency, has significant effects on fluid and electrolyte regulation in athletic horses.
Publication Date: 1999-05-08 PubMed ID: 10233125DOI: 10.1152/jappl.1999.86.5.1610Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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This research investigates the impact of differing eating patterns and salt intake on the fluid and electrolyte regulation in athletic horses. Key findings suggest that voluntarily ingesting sodium has considerable effects on such regulation, while feeding frequency does not significantly affect these aspects.
Study Design
- The researchers conducted an experiment on six athletic horses to understand the influence of feeding frequency and voluntary sodium intake (VSI) on the fluid shifts and the concentration of plasma aldosterone (PAC).
- The horses were subjected to two different feeding regimes: they were fed either twice a day (2TD) or six times a day (6TD). Each protocol lasted for 25 days.
- VSI was monitored by weighing the horse’s salt block each day.
Results and Findings
- Neither the 2TD nor the 6TD feeding schedule significantly changed fluid shifts in the horses.
- However, with the 2TD treatment, there was a noticeable increase in the concentration of plasma proteins and osmolality, occurring after feeding and persisting for less than an hour.
- Both PAC and VSI were unaltered by the variations in feeding frequency.
- Sodium intake showed significant fluctuation, ranging from 0 to 62 mg per kg of body weight each day. These fluctuations correspondingly affected PAC.
- When the sodium intake was less than 26 mg per kg of body weight each day, a diurnal rhythm for PAC was observed.
- Water consumption, fecal concentrations of sodium and potassium, and packed cell volumes during exercise were all affected by the variations in sodium intake.
- The horses demonstrated the same response towards exercise irrespective of the feeding protocol.
Conclusion
- The study concluded that voluntary salt or sodium intake has substantial effects on fluid and electrolyte regulation in athletic horses.
- Feeding frequency, however, was not found to significantly influence fluid and electrolyte regulation.
Cite This Article
APA
Jansson A, Dahlborn K.
(1999).
Effects of feeding frequency and voluntary salt intake on fluid and electrolyte regulation in athletic horses.
J Appl Physiol (1985), 86(5), 1610-1616.
https://doi.org/10.1152/jappl.1999.86.5.1610 Publication
Researcher Affiliations
- Department of Animal Physiology, Swedish University of Agricultural Sciences, S-750 07 Uppsala, Sweden. Anna.Jansson@difys.slu.se
MeSH Terms
- Aldosterone / blood
- Animals
- Circadian Rhythm / drug effects
- Circadian Rhythm / physiology
- Drinking / drug effects
- Drinking / physiology
- Eating / physiology
- Exercise Test
- Feces / chemistry
- Fluid Shifts / drug effects
- Horses / physiology
- Male
- Potassium / blood
- Sodium / blood
- Sodium Chloride, Dietary / pharmacology
- Water-Electrolyte Balance / drug effects
- Water-Electrolyte Balance / physiology
Citations
This article has been cited 14 times.- Harvey AM, Ramp D, Mellor DJ. Review of the Foundational Knowledge Required for Assessing Horse Welfare. Animals (Basel) 2022 Dec 1;12(23).
- Saastamoinen M, Särkijärvi S, Suomala H. Protein Source and Intake Effects on Diet Digestibility and N Excretion in Horses-A Risk of Environmental N Load of Horses. Animals (Basel) 2021 Dec 15;11(12).
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- Freeman DE. Effect of Feed Intake on Water Consumption in Horses: Relevance to Maintenance Fluid Therapy. Front Vet Sci 2021;8:626081.
- Saastamoinen M, Särkijärvi S, Valtonen E. The Effect of Diet Composition on the Digestibility and Fecal Excretion of Phosphorus in Horses: A Potential Risk of P Leaching?. Animals (Basel) 2020 Jan 15;10(1).
- Connysson M, Rhodin M, Jansson A. Effects of Horse Housing System on Energy Balance during Post-Exercise Recovery. Animals (Basel) 2019 Nov 14;9(11).
- Ekman S, Lindahl A, Rüetschi U, Jansson A, Björkman K, Abrahamsson-Aurell K, Björnsdóttir S, Löfgren M, Hultén LM, Skiöldebrand E. Effect of circadian rhythm, age, training and acute lameness on serum concentrations of cartilage oligomeric matrix protein (COMP) neo-epitope in horses. Equine Vet J 2019 Sep;51(5):674-680.
- Stefánsdóttir GJ, Gunnarsson V, Roepstorff L, Ragnarsson S, Jansson A. The effect of rider weight and additional weight in Icelandic horses in tölt: part I. Physiological responses. Animal 2017 Sep;11(9):1558-1566.
- Zeyner A, Romanowski K, Vernunft A, Harris P, Müller AM, Wolf C, Kienzle E. Effects of Different Oral Doses of Sodium Chloride on the Basal Acid-Base and Mineral Status of Exercising Horses Fed Low Amounts of Hay. PLoS One 2017;12(1):e0168325.
- Ringmark S, Lindholm A, Hedenström U, Lindinger M, Dahlborn K, Kvart C, Jansson A. Reduced high intensity training distance had no effect on VLa4 but attenuated heart rate response in 2-3-year-old Standardbred horses. Acta Vet Scand 2015 Mar 20;57(1):17.
- Chittavong M, Jansson A, Lindberg JE. Effects of high dietary sodium chloride content on performance and sodium and potassium balance in growing pigs. Trop Anim Health Prod 2013 Oct;45(7):1477-83.
- Chittavong M, Lindberg JE, Jansson A. A field study on feed supplementation, body weight and selected blood parameters in local pigs in Laos. Trop Anim Health Prod 2013 Feb;45(2):505-10.
- Abraham AJ, Duvall ES, Doughty CE, Riond B, Ortmann S, Terranova M, le Roux E, Clauss M. Sodium Retention in Large Herbivores: Physiological Insights and Zoogeochemical Consequences. J Exp Zool A Ecol Integr Physiol 2025 Jul;343(6):664-676.
- Alshut F, Venner M, Martinsson G, Vervuert I. The effects of feeding sodium chloride pellets on the gastric mucosa, acid-base, and mineral status in exercising horses. J Vet Intern Med 2023 Nov-Dec;37(6):2552-2561.
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