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Cyclical plasma electrolyte and acid–base responses to meal feeding in horses over a 24-h period

Published online by Cambridge University Press:  09 March 2007

Amanda Waller ,
Kerri Jo Smithurst ,
Gayle L Ecker ,
Ray Geor  and
Michael I Lindinger
Amanda Waller*
Affiliation:
Department of Human Biology and Nutritional Sciences, University of Guelph, Guelph, ON, Canada N1G 2W1
Kerri Jo Smithurst
Affiliation:
Department of Human Biology and Nutritional Sciences, University of Guelph, Guelph, ON, Canada N1G 2W1
Gayle L Ecker
Affiliation:
Equine Centre, University of Guelph, Guelph, ON, Canada N1G 2W1
Ray Geor
Affiliation:
Department of Biomedical Sciences, University of Guelph, Guelph, ON, Canada N1G 2W1
Michael I Lindinger
Affiliation:
Department of Human Biology and Nutritional Sciences, University of Guelph, Guelph, ON, Canada N1G 2W1
*
*[email protected]
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Abstract

The present study used the physicochemical approach to characterize the changes in plasma electrolyte and acid–base states that occur in horses in response to feeding. Jugular venous blood was sampled every 0.5–2 h over a 24-h period from two groups (n = 4 and n = 5) of Standardbreds fed a mixed hay and grain ration at 8 am and 7 pm. One group of horses was studied in October, and one in December. The time course and magnitude of feeding responses differed between groups, and between the morning and evening meals. Feeding-induced changes in plasma electrolyte and acid–base variables occurred rapidly, within the first 1–3 h of meal consumption. The plasma acidosis associated with eating the meal was marked by increased plasma [H+] and decreased TCO2. The primary contributors to the increases in plasma [H+] were the decrease in the plasma concentration of strong ions ([SID]) and the pCO2. The increase in plasma total weak acid (protein) concentration ([Atot]) post-feeding had only a minor effect on the acid–base state. The feeding-induced acidosis abated 3–6 h after the meal, showing cyclical recovery of physicochemical variables that contributed to the acid–base disturbance. It is concluded that several key plasma electrolyte and acid–base parameters undergo significant, cyclical fluctuations in response to feeding in horses.

Keywords

equinepHH+physicochemical approachnutrition
Type
Research Article
Information
Equine and Comparative Exercise Physiology , Volume 2 , Issue 3 , August 2005 , pp. 159 - 169
Copyright
Copyright © Cambridge University Press 2005

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References

1Hasselbalch, K (1912). Neutralitatsregulation und reizbarkeit des atemzentrums in ihren Wirkungen auf die koklensaures-pannung des Blutes. Biochemistry-Zeitschrift 46: 403–439.Google Scholar
2Carlson, GP (2000). Fluid, electrolyte and acid–base balance. In: Kaneko, JJ, Harvey, JW & Bruss, ML (eds), Clinical Biochemistry of Domestic Animals. Toronto: Academic Press, pp. 485–516.Google Scholar
3Lindinger, MI (2004). Acid–base physiology during exercise and in response to training. In: Hinchcliff,, KW, Kaneps, AJ & Geor, RJ (eds), Equine Sports Medicine and Surgery: Basic and Clinical Sciences of the Athletic Horse Chapter 39. New York: Elsevier, pp. 586–610.Google Scholar
4Stewart, PA (1983). Modern quantitative acid–base chemistry. Canadian Journal of Physiology and Pharmacolgy 61: 1441–1461.Google ScholarPubMed
5Waller, A, Armstrong, S, Smithurst, K-J and Lindinger, MI (2004). Effects of diet, feeding and diurnal variation on acid–base balance in horses. Equine and Comparative Exercise Physiology 1: 153–165.Google Scholar
6Kerr, MG and Snow, DH (1982). Alterations in haematocrit, plasma proteins and electrolytes in horses following the feeding of hay. The Veterinary Record 110: 538–540.Google Scholar
7Stutz, WA, Topliff, DR, Freeman, DW, Tucker, WB, Breazile, JW and Wall, DL (1992). Effect of dietary cation–anion balance on blood parameters in exercising horses. Equine Veterinary Science 12: 164–167.CrossRefGoogle Scholar
8Clarke, LL, Ganjam, VK, Fichtenbaum, B, Hatfield, D and Garner, HE (1988). Effect of feeding on renin–angiotensin–aldosterone system of the horse. American Journal of Physiology 254: R524–R530.Google ScholarPubMed
9Yashiki, K, Kusunose, R and Takagi, S (1995). Diurnal variations of blood constituents in young thoroughbred horses. Journal of Equine Science 6: 91–97.CrossRefGoogle Scholar
10Jansson, A and Dahlborn, K (1999). Effects of feeding frequency and voluntary salt intake on fluid and electrolyte regulation in athletic horses. Journal of the American Physiological Society 86: 1610–1616.Google ScholarPubMed
11Constable, PD (1997). A simplified strong ion model for acid–base equilibria: application to horse plasma. Journal of Applied Physiology 83: 297–311.CrossRefGoogle ScholarPubMed
12Lindinger, MI, Heigenhauser, GJF, McKelvie, RS and Jones, NL (1992). Blood ion regulation during repeated maximal exercise and recovery in humans. American Journal of Physiology 262: R126–R136.Google ScholarPubMed
13Meyer, H (1996). Influence of feed intake and composition, feed and water restriction, and exercise on gastrointestinal fill in horses. Part 3. Equine Practice 18: 25–28.Google Scholar
14Eckersall, PD (1984). Equine whole saliva: a sample collection system and biochemical analysis. The Veterinary Record 115: 437–438.CrossRefGoogle ScholarPubMed
15van der Merwe, MT, Schlaphoff, GP, Crowther, NJ, Boyd, IH, Gray, IP, Joffe, BI and Lonnroth, PN (2001). Lactate and glycerol release from adipose tissue in lean, obese, and diabetic women from South Africa. Journal of Clinical Endocrinology and Metabolism 86: 3296–3303.Google ScholarPubMed
16Korach-Andre, M, Roth, H, Barnoud, D, Pean, M, Peronnet, F and Leverve, X (2004). Glucose appearance in the peripheral circulation and liver glucose output in men after a large 13C starch meal. American Journal of Clinical Nutrition 80: 881–886.CrossRefGoogle ScholarPubMed
17Fonnesbeck, PV (1968). Consumption and excretion of water by horses receiving all hay and hay–grain diets. Journal of Animal Science 27: 1350–1356.CrossRefGoogle Scholar
18Baker, LA, Topliff, DR, Freeman, DW, Teeter, RG and Breazile, JW (1992). Effect of dietary cation–anion balance on acid–base status in horses. Journal of Equine Veterinary Science 12: 160–163.CrossRefGoogle Scholar
19Popplewell, JC, Topliff, DR, Freeman, DW and Breazile, JE (1993). Effects of dietary cation–anion balance on acid base balance and blood parameters in anaerobically exercised horses. Journal of Equine Veterinary Science 13: 552–555.CrossRefGoogle Scholar
20Mueller, RK, Cooper, SR, Topliff, DR, Freeman, DW, MacAllister, C and Carter, SD (2001). Effect of dietary cation–anion difference on acid–base status and energy digestibility in sedentary horses fed varying levels and types of starch. Journal of Equine Veterinary Science 21: 498–502.CrossRefGoogle Scholar