Effect of conditioning on exercise-induced hyperthermia and post-exercise cooling in dogs

2018 ◽  
Vol 14 (2) ◽  
pp. 91-97 ◽  
Author(s):  
J.A. Baker ◽  
M.S. Davis
Keyword(s):  
Thermal Stress ◽  
Body Temperature ◽  
Prospective Study ◽  
Oxygen Concentration ◽  
Rectal Temperature ◽  
Post Exercise ◽  
Temperature Changes ◽  
Hypoxic Conditions ◽  
Sled Dogs ◽  
Exercise Induced

Our objective was to evaluate the effect of conditioning and hypoxia on rectal and gastrointestinal temperature changes in dogs exercising at cold ambient temperature. Six Alaskan Husky sled dogs, each in a physically conditioned and unconditioned state, were used in the prospective study. Dogs in peak physical condition were run untethered on a treadmill under normoxic and hypoxic conditions of 20 and 12.5% environmental oxygen concentration, respectively, on separate days. After undergoing a deconditioning period of four months, the same dogs were run again under the same environmental conditions of 20 and 12.5% O2. Body temperature measurements were obtained via digital rectal thermometer and ingestible gastrointestinal thermistor at baseline, every 5 min for 30 min of exercise, and for 15 min following cessation of exercise. Under hypoxic conditions, peak gastrointestinal temperature was lower in conditioned vs unconditioned dogs. Gastrointestinal cooling was faster in conditioned dogs under normoxic conditions only. There was no difference in the peak rectal temperature, or rate of rectal temperature cooling in either normoxic or hypoxic conditions. 3 of 6 (50%) of the conditioned dogs reached a plateau temperature after approximately 20 to 25 min. This was observed less frequently when the dogs were unconditioned. Gastrointestinal and rectal temperatures reacted differently to exercise depending on conditioning or environmental oxygen concentration and this suggests that they cannot be used interchangeably to assess body temperature. Under these conditions, conditioning had no effect on rectal temperature. Presence of a plateau effect of rectal or gastrointestinal temperature may demonstrate a thermoregulatory balance of heat production and heat loss and may be a helpful measure in assessing individual dogs’ level of conditioning with regard to resistance to thermal stress.

scholarly journals Supplemental Fiber Affects Body Temperature and Fecal Metabolites but Not Respiratory Rate or Body Composition in Mid-Distance Training Sled Dogs

2021 ◽  
Vol 8 ◽  
Author(s):  
Emma Thornton ◽  
Eve Robinson ◽  
James R. Templeman ◽  
Lindy Bruggink ◽  
Michael Bower ◽  
...  
Keyword(s):  
Body Composition ◽  
Body Temperature ◽  
Respiratory Rate ◽  
Dry Matter ◽  
Gut Health ◽  
Soluble Fiber ◽  
Post Exercise ◽  
Distance Training ◽  
Sled Dogs ◽  
Matter Basis

Dietary fiber affects canine physiology in many ways, such as increasing colonic absorption of water and improving gut health, both of which may positively impact exercise performance. The objectives of this study were to investigate the effects of increased dietary soluble fiber and incremental training on respiratory rate (RR), internal body temperature (BT), body composition, and fecal metabolites in mid-distance training sled dogs. Fourteen dogs (12 Siberian and 2 Alaskan Huskies) were blocked by age, sex, and body weight (BW) and then randomly allocated into one of two diet groups. Seven dogs were fed a dry extruded control diet (Ctl) with an insoluble:soluble fiber ratio of 4:1 (0.74% soluble fiber on a dry-matter basis), and seven dogs were fed a dry extruded treatment diet (Trt) with an insoluble:soluble fiber ratio of 3:1 (2.12% soluble fiber on a dry-matter basis). Fecal samples were taken once a week. All dogs underwent 9 weeks of incremental exercise conditioning where the running distance was designed to increase each week. Every 3 weeks, external telemetry equipment was used to non-invasively measure and record RR and internal BT at resting, working, and post-exercise recovery states. Body composition was measured on weeks −1 and 9 using quantitative magnetic resonance. Body composition, RR, BT, and fecal metabolites were analyzed using a mixed model with dog as a random effect and week and diet group as fixed effects. Dogs on Trt had lower working and post-exercise BT than Ctl (P < 0.05). In addition, Trt dogs had lower recovery BT at weeks 2 and 5 than Ctl dogs (P < 0.05). Treatment dogs had greater fecal short-chain fatty acid concentrations than Ctl (P < 0.05). Diet had no effect on RR or body composition (P > 0.10), but exercise resulted in an overall 7% increase in lean and 3.5% decrease in fat mass (P < 0.05). These data suggest that increasing dietary soluble fiber may positively influence BT and gut health; however, it has no effect on RR or body composition. Soluble fiber did not negatively impact any measures of overall health and performance and should be considered for use in performance dogs.

Studies on the adaptability of three breeds of sheep to a tropical environment modified by altitude IV. Role of the fleece in thermoregulation in German Merino ewes

1960 ◽  
Vol 55 (3) ◽  
pp. 311-315
Author(s):  
R. B. Symington
Keyword(s):  
Thermal Stress ◽  
Body Temperature ◽  
Respiratory Rate ◽  
Skin Temperature ◽  
Rectal Temperature ◽  
High Heat ◽  
Diurnal Fluctuation ◽  
Body Temperature Regulation ◽  
Southern Rhodesia

The influence of fleece on thermoregulation in German Merino ewes was investigated in Rhodesia. Comparative heat tolerances of Persian Blackhead, indigenous Native and shorn and unshorn Merino ewes were obtained during the hottest month of the year in Northern Rhodesia. The main thermolytic responses in unshorn, partially shorn and completely shorn Merino ewes were measured at 7.0 a.m.; 10.0 a.m.; 1.0 p.m. and 4.0 p.m. during April in Southern Rhodesia.1. Unshorn Merino ewes showed more and shorn Merino ewes less effective body temperature regulation than Persian or Native ewes. High heat tolerance in unshorn Merinos was due primarily to insulation by the fleece and not to more efficient physiological thermolysis than in hair breeds. No ewe showed signs of undue thermal stress and feed intake was not affected by heat.2. Increases in rectal temperature and respiratory rate between 7.0 a.m. and 1.0 p.m. of Merinos in Southern Rhodesia were related inversely to fleece length. Body temperature did not differ significantly at 1.0 p.m. owing to differential rates of increase in respiratory rate.3. Magnitude of the diurnal fluctuation in skin temperature was also related inversely to fleece length. Partially shorn ewes, however, began with and maintained highest skin temperature through the heat of the day. In all groups skin temperature fell after 10.0 a.m. although ambient temperature continued to rise. This fall could not be attributed to sweating since moisture secretion declined simultaneously.

Influence of water temperature on oxygen uptake by swimming rats

1964 ◽  
Vol 19 (6) ◽  
pp. 1215-1218 ◽  
Author(s):  
Mary Ann Baker ◽  
Steven M. Horvath
Keyword(s):  
Thermal Stress ◽  
Body Temperature ◽  
Oxygen Uptake ◽  
Rectal Temperature ◽  
Hot Water ◽  
Swimming Time ◽  
Cold Environments ◽  
Influence Of Water ◽  
The Mean ◽  
Neutral Water

Oxygen uptake and rectal temperature of ten rats forced to swim to exhaustion or for 45 min in cold, hot, and thermoneutral water were measured during swimming. In 20 C water rats swam for 12.6 min and had a final rectal temperature of 26.9 C. In 42 C water the mean swimming time was 14.1 min and the final rectal temperature was 42.6 C. All rats swam for 45 min in water of 37 C, and the final rectal temperature was not different from the preswim temperature. Oxygen uptake during swimming in 37 C water rose and stabilized at a rate of about three times basal in a pattern suggesting that the swimming work was moderate. Animals swimming in cold and hot water were exhausted before their oxygen uptakes stabilized, but the increasing oxygen uptakes during the early parts of these swims were similar to that in neutral water. It appeared that while the metabolic rate was adjusted to the level of work and was not greatly affected by severe changes in body temperature, alterations in body temperature profoundly influenced the duration of work in the hot or cold environments. exercise and thermal stress; exercise metabolism Submitted on March 23, 1964

scholarly journals Distiller’s dried grain with solubles (Zea mays L) in the diet of sheep reared in the tropical region of Brazil: ingestive behavior and physiological parameters

2018 ◽  
Vol 39 (3) ◽  
pp. 1267
Author(s):  
Luiz Juliano Valério Geron ◽  
Sílvia Cristina de Aguiar ◽  
Jocilaine Garcia ◽  
Lúcia Maria Zeoula ◽  
Kallynka Samara Martins Coelho ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Body Temperature ◽  
Water Intake ◽  
Rectal Temperature ◽  
Physiological Parameters ◽  
Respiratory Frequency ◽  
Ingestive Behavior ◽  
Tropical Environment ◽  
Tropical Region ◽  
Regression Equations

This study aimed to evaluate the effects of inclusion of different levels of distiller’s dried grain with solubles (DDGS) in the diet of sheep raised in the tropical region of Brazil on ingestive behavior and physiological parameters. We used four sheep with mean body weight (BW) of 25 ± 2 kg, distributed in a Latin square design, with four periods, and four DDGS inclusion levels (0, 8, 16, and 24%). The sheep were placed in metabolism cages, and received two meals per day. The data on ingestive behavior and physiological parameters of the sheep were analyzed with analysis of variance (ANOVA), and the observed differences were tested using regression equations at 5% probability. The inclusion of DDGS levels in sheep diets did not change the time spent on ingestive behavior, such as dry matter intake (DMI), rumination (RUM), resting (RES), water intake (WAI), and other activities (OAC) expressed in minutes. However, during the night period, there was an increase (p < 0.05) in the time spent ruminating in relation to the daytime period. However, there was a reduction (p < 0.05) in the time spent on the activities of RES and WAI of the sheep. The inclusion of DDGS in sheep rations did not change (p > 0.05) the physiological parameters measured. However, we found that the afternoon period influenced (p < 0.05) the physiological parameters evaluated, such as body temperature of the front (BTF), body temperature of the rear (BTR), rectal temperature (RET), and respiratory frequency (REF), which were higher in relation to the values observed in the morning. Thus, we conclude that the inclusion of up to 24% of dried distillery grains with solubles in the feeding of sheep in the tropical region of Brazil does not alter the ingestive behavior and physiological parameters of sheep. However, sheep raised in confinement in the tropical region of Brazil spent more time ruminating at night. During the day, sheep spent more time on resting activities and water intake. In addition, sheep raised in a tropical environment need to be monitored for thermal stress during the afternoon, due to the increase in rectal temperature and respiratory frequency. In addition, sheep raised in a tropical environment require greater monitoring of thermal stress during the afternoon, due to the elevation of physiological parameters such as rectal temperature and respiratory frequency in this period.

When body temperature changes, does rectal temperature lag?

2004 ◽  
Vol 144 (6) ◽  
pp. 824-826 ◽  
Author(s):  
David S. Greenes ◽  
Gary R. Fleisher
Keyword(s):  
Body Temperature ◽  
Rectal Temperature ◽  
Temperature Changes

Body temperature lability in sheep and goats during short-term exposures to heat and cold

1971 ◽  
Vol 77 (2) ◽  
pp. 267-272 ◽  
Author(s):  
K. G. Johnson
Keyword(s):  
Thermal Stress ◽  
Body Temperature ◽  
Respiratory Rate ◽  
Air Temperature ◽  
Domestic Animals ◽  
The Body ◽  
Body Core Temperature ◽  
Short Term ◽  
Temperature Changes ◽  
Body Core

SummaryPassive lability of body core temperature during brief exposures to thermal stress is an efficient means of thermoregulation which few species of domestic animals appear to utilize. The body temperature changes of 30 shorn sheep and 10 shorn goats have been measured during standard heat and cold exposures lasting 7 h. During exposures to heat, air temperature was increased from 20 °C to 45 °C then reduced again to 20 °C. Rectal temperatures of goats and Soay, Welsh Mountain, Merino and Clun Forest sheep rose by an average of 1·96 °C, 1·22 °C, 1·04 °C, 0·85 °C and 0·80 °C respectively. All animals had similar increases in respiratory rate. During exposures to cold, air temperature was reduced from 20 °C to about 6 °C then increased again to 20 °C. Rectal temperatures rose by 0·18–0·20 °C in goats and in all sheep except Soays in which they fell by 0·28 °C. All animals showed moderate to vigorous shivering. None of the animals exhibited passive body temperature lability as an adaptation to thermal stress.

scholarly journals Body temperatures of free-living African penguins (Spheniscus demersus) and bank cormorants (Phalacrocorax neglectus).

1996 ◽  
Vol 199 (10) ◽  
pp. 2215-2223 ◽  
Author(s):  
R P Wilson ◽  
D Grémillet
Keyword(s):  
Body Temperature ◽  
Critical Level ◽  
Free Living ◽  
Post Exercise ◽  
Temperature Changes ◽  
Stomach Temperature ◽  
Spheniscus Demersus ◽  
Water Birds ◽  
African Penguin ◽  
Activity Dependent

Two free-living seabirds (the African penguin Spheniscus demersus and the bank cormorant Phalacrocorax neglectus) were equipped with stomach temperature-loggers to study body temperature changes during foraging. Body temperature in these endotherms was environmentally and activity-dependent and varied in the case of the cormorant by over 5 degrees C. Considerations of heat flux show that such flexibility confers considerable energetic advantages: by allowing body temperature to drop when the heat loss to the environment is high, such as in water, birds may save the energy that would normally be necessary to compensate for this drop. It appears that, in cormorants, low body temperature resulting from extended time in water can subsequently be elevated using solar energy when birds return to land in a manner similar to that of ectotherms. In the better-insulated penguins, muscle-generated heat during swimming is used to re-elevate low body temperature. Continued swimming eventually causes body temperature to rise above normal resting levels so that metabolic rate could theoretically be dramatically reduced immediately post-exercise when the temperature drops to some critical level before any increase in metabolism is necessary to correct it.

scholarly journals Effects of incremental exercise and dietary tryptophan supplementation on the amino acid metabolism, serotonin status, stool quality, fecal metabolites, and body composition of mid-distance training sled dogs

2020 ◽  
Vol 98 (5) ◽  
Author(s):  
James R Templeman ◽  
Emma Thornton ◽  
Cara Cargo-Froom ◽  
Eli J Squires ◽  
Kelly S Swanson ◽  
...  
Keyword(s):  
Body Composition ◽  
Fixed Effects ◽  
Control Diet ◽  
Random Effect ◽  
Post Exercise ◽  
Nutritional Interventions ◽  
Sled Dogs ◽  
Exercise Regimen ◽  
Composition Optimization ◽  
Exercise Induced

Abstract Exercise improves the health of dogs; however, the extreme exertion experienced by sled dogs may lead to variable metabolic and fecal characteristics. Nutritional interventions, such as dietary tryptophan (Trp), may reduce the prevalence of these exercise-induced disturbances. Sporting diets tend to have high crude protein concentrations in contrast to adult maintenance diets and this results in less Trp relative to other amino acids (AA). Therefore, sporting dogs represent an ideal cohort to assess the effects of supplemental Trp. The objective was to evaluate the effects of supplemental dietary Trp and an incremental training regimen on AA and serotonin status, fecal scores and metabolites, and body composition in client-owned Siberian huskies. Sixteen dogs (nine females and seven males) were used, with a mean age of 4.8 ± 2.5 yr and body weight (BW) of 24.3 ± 4.3 kg. Dogs were blocked for sex, age, and BW and randomly allocated into two groups with eight fed a dry extruded control diet (Ctl) and eight fed Ctl supplemented with Trp to reach a Trp:large-neutral AA (LNAA) ratio of 0.075:1 (treatment, Trt). The exercise regimen was designed to increase in distance each week, but weather played a role in setting the daily distance. Each week BW was recorded and food allotments were adjusted to maintain initial BW. Pre and post-exercise blood samples were taken every 3 wk, dogs then received a meal followed by 1, 2, and 4 h post meal blood collections (serum AA, serotonin). Stool collection and scoring occurred each week and body composition was measured on weeks −1 and 11. Serotonin, AA, fecal metabolite, and body composition data were analyzed using PROC MIXED of SAS with dog as a random effect and week and Trt as fixed effects. Stool score data were analyzed using PROC FREQ to compare stool score and Trt, and PROC CORR was used to analyze associations between fecal score, temperature, humidity, and run distance. Dogs on Trt had greater fasted Trp compared with baseline, greater post-meal Trp and serotonin compared with baseline, greater post-meal Trp compared with fasted, and greater post-meal Trp and serotonin compared with Ctl (P &lt; 0.05). Fecal data indicated that Trp improved stool scores (P &lt; 0.05) yet had no effect on fecal metabolites. An overall increase in lean and decrease in fat mass was found (P &lt; 0.05), but Trt had no effect on body composition. Optimization of the dietary Trp:LNAA ratio may help to improve GI health without compromising performance in actively training sled dogs.

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