Effects of the Daily Administration of a Rehydrating Supplement to Trotter Horses

Abstract

An interesting aspect of athlete horse management is connected with the effects of the profuseThe energy required to power muscle activity in athlete horses is drawn from the diet and/or body stores via a comparatively inefficient process, since about 80% of this energy is lost in the form of heat [17]; h e a t i s d i s p e r s e d t h r o u g h f o u r f un d a m e n t a l mechanisms: irradiation, convection, conduction and evaporation.I n e q u i d s , s w e a t t h u s r e p r e s e n t s t h e m a i n thermoregulatory mechanism (55-60%), whereas losses through breathing account for about 25% [14]. Intense exercise may induce thermal stress; heat p r o d u c t i o n e x c e e d s d i s p e r s i o n i n a d v e r s e environmental conditions, e.g. high temperature and/ or humidity [18].According to McConaghy [17] horses, despite their double sweating ability, are more prone than man to thermal stress. According to McCutcheon and Geor [18], training and warm acclimation, by reducing the amount of sweat required to achieve thermoregulation, result in decreased loss of water and ions.Evaporation of 1 litre of sweat disperses the 580 kcal produced in 5-6 min of submaximal exercise (100 kcal/ min) or in 1-2 min of maximal effort (450 kcal/min) [17]. Thoroughbreds and trotters can lose up to 10 l in races of 1 or 2 miles (1,600-3,200 m), and 35-40 l in an endurance race of 5 hr in a temperate climate [14].Unless these heavy water losses are restored soon, severe dehydration may arise, with fatal consequences in 12-15% of cases.The effects of moderate dehydration in horses are probably similar to those observed in man, where impaired physical performances are seen already with losses accounting for 2-4% body weight [3]. The decrease in blood volume induced by dehydration entails decreased perfusion not only of muscles

Metabolic and hematological profiles in mature horses supplemented with different selenium sources and doses1,2

“…Enzyme activities that reflect cellular damage, because these enzymes are released into the circulatory fluid when cell membrane integrity is damaged, were not affected by the treatment in this study. The activity of AST was not affected by treatment and was well within published normal ranges (Falaschini et al, 2005;Harvey et al, 2005;Pieralisi and Comazzi, 2006). Plasma CK activity was not affected by treatment; however, the effect on this enzymatic activity is generally demonstrable only in some physiological phases and when Se is considerably deficient in the diet (Arthur, 1988).…”

Blood and urinary variables in horses supplemented with electrolytes

“…Warren et al (1999) and Bayly et al (2006) observed values of plasma chloride concentrations of 104 and 99.8 mmol/l, respectively. A higher concentration of plasma chloride of 118 mmol/l was observed by Falaschini et al (2005) in horses fed conventional diet. Vervuert et al (2006) observed total calcium plasma concentration of 3.16 mmol/l and total magnesium plasma concentration of 0.77 mmol/l in horses before exercise.…”

“…Unlike observed for calcium, magnesium and chloride, the plasma concentrations of potassium in our study were below the concentrations observed in other studies. Larsen et al (1996), Schott II et al (2002), Bayly et al (2006), Sampieri et al (2006), andMuñoz et al (2008) observed in horses at rest a potassium plasma concentrations between 3.0 and 4.0 mmol/l; Jansson et al (2002), Falaschini et al (2005), Waller et al (2008), andMuñoz et al (2010) observed values between 4.0 and 4.5 mmol/l; and Warren et al (1999) and Robert et al (2010) observed values above 4.5 mmol/l. The potassium concentration in plasma may vary depending on the uptake capacity of cells to transport potassium from the extracellular to the intracellular environment.…”