Sweat composition in Arabian horses performing endurance exercise on forage‐based, low Na rations

Abstract

SummaryReasons for performing study: Excessive sweat loss during endurance exercise may lead to electrolyte disturbances and previous research suggests dietary factors may affect hydration status. While investigating the effect of dietary fibre type on hydration status, sweat samples were collected which allowed for the evaluation of sweat composition in horses consuming forage-based, low sodium (Na) rations. Objective: To investigate sweat composition in Arabian horses performing endurance type exercise while fed forage-based, rations low in Na. . Na and Cl concentrations were lower than those previously reported. Conclusions: Differences in sweat constituents due to diet were observed, but more importantly both Na and Cl concentration are lower than those previously reported perhaps due to low dietary Na intake or breed of animal.evj_208 382..386

Effects of Different Oral Doses of Sodium Chloride on the Basal Acid-Base and Mineral Status of Exercising Horses Fed Low Amounts of Hay

“…Breed or even individual differences may also play a role. Spooner et al [18] observed a comparatively low sodium content in the sweat of Arabian horses. Evaporation of water during sweat collection may lead to an overestimate of the electrolyte content of sweat [5].…”

Muscle physiology and nutrition in exercising horses

“…2010). Another study documented unusually low sweat sodium concentrations during exercise in horses consuming 3 different forage rations providing sodium at only 6.6% of National Research Council (NRC) recommendation (Spooner et al . 2010).…”

Sensitivity of ponies to sodium in the drinking water

“…In horses, loss of Na via sweat plays an important role in their Na metabolism because they rely on sweating as major mechanism for heat dissipation during exercise (Coenen, 2005; Cohen et al, 1993; McCutcheon & Geor, 2014; Meyer et al, 1990). Horse sweat is hypertonic in relation to the plasma and contains considerable amounts of Na, ranging between 2.0 and 5.7 g/L (reviewed by Spooner et al, 2010). However, the sweat glands do not conserve Na, regardless of the horse's body stores (Lindner et al, 1983; Spooner et al, 2010).…”

“…Horse sweat is hypertonic in relation to the plasma and contains considerable amounts of Na, ranging between 2.0 and 5.7 g/L (reviewed by Spooner et al, 2010). However, the sweat glands do not conserve Na, regardless of the horse's body stores (Lindner et al, 1983; Spooner et al, 2010). Sweat losses of around 1 L/100 kg body weight (BW) per hour during light exercise under temperate conditions (in Welsh ponies and crossbreeds, Meyer et al, 1990) may increase to 2–2.5 L/100 kg BW per hour when exercised in hot, humid conditions (NRC, 2007), thus leading to excessive Na losses.…”