Seasonal variations in physiological and behavioural parameters in a bachelor group of stallion ponies (Equus caballus)

2006 ◽  
Vol 82 (5) ◽  
pp. 581-590 ◽  
Author(s):  
M. C. G. Davies Morel ◽  
S. D. McBride ◽  
R. S. Chiam ◽  
A. McKay ◽  
E. Ely
Keyword(s):  
Body Weight ◽  
Metabolic Rate ◽  
Ambient Temperature ◽  
Significant Relationship ◽  
Fibre Length ◽  
Day Length ◽  
Testis Size ◽  
Adaptive Changes ◽  
Forage Availability ◽  
Energy Conserving

AbstractAnimals living in temperate climates are continually adapting to seasonal demands of reproduction and survival. Whilst it is well documented that ruminants show seasonal changes in both reproductive and non-reproductive physiological and behavioural characteristics (reduction of metabolic rate and appetite during the winter with respective increases during spring and summer), this information has not been fully established in the non-ruminating ungulate species of Equidae. This may be important information from a practical management perspective since groups of equids are increasingly being kept in natural conditions for the purposes of conservation grazing.The aim of this study, therefore, was to document the behavioural and physiological adaptive changes made by ponies during a 12-month period and to relate these to changes in forage availability and environment. Five mature pony stallions were kept in west Wales (4°5′W, 52°25′N) and monitored for 12 months. A range of physiological (testis size, body weight, condition score (CS), hoof growth, moult (M), pelage fibre length, depth and density) and behavioural measurements (foraging and non-foraging activities) were recorded along with monthly forage analysis (crude protein (CP), water-soluble carbohydrates (WSC)), dry matter (DM)) and environmental conditions (day length and minimum ambient temperature). All physiological measurements were significantly (P<0·001 to P<0·05, r2=0·16 to 0·69) related to day length and all except testis size, body weight and M were significantly related to minimum temperature, CS (P<0·001; r2=0·583), hoof growth (P<0·001; r2=0·457), pelage fibre length (P<0·001; r2=0·61), pelage fibre depth (P<0·001; r2=0·489) and pelage density (P<0·05; r2=0·192). Fewer significant relationships were observed in relation to forage characteristics; significances only obtained between CP and CS (P<0·001; r2=0·854), fibre length (P<0·01; r2=0·625) and pelage fibre depth (P<0·01; r2=0·624); between DM and CS (P<0·05; r2=0·352) and pelage fibre depth (P<0·05; r2=0·343); between WSC and pelage fibre depth (P<0·01; r2=0·55) and pelage fibre depth (P<0·05; r2=0·34). Behaviour results showed a significant relationship between time spent alert and day-length (P<0·05; r2=0·35) and between minimum ambient temperature and time spent eating (P<0·05; r2=0·37), locomotory behaviour (P<0·01; r2=0·53) and passive interaction (P=0·001; r2=0·63). A significant relationship was also reported between eating and CP (P<0·01; r2=0·53) as well as DM (P=0·01; r2=0·43). The ponies in this study demonstrated a series of adaptive changes during winter concomitant with energy conservation, however, forage availability and intake also decreased indicating lower energy input. Despite energy conserving adaptations it is unlikely that nutrient intake was adequate to account for the limited winter decline in CS and weight. In conclusion, it was considered that: (a) ponies demonstrated physiological and behavioural adaptation in response to environmental demands, (b) during winter ponies demonstrated behaviours indicative of a cost benefit analysis of expending energy in the pursuit of poor quality forage, (c) despite energy conserving adaptations, intake is unlikely to have been adequate to maintain the CS observed, and (d) reduction in metabolic rate and increased food conversion efficiency may be additional adaptations made during times of environmental challenge.

Some consequences of body size

1984 ◽  
Vol 247 (4) ◽  
pp. H495-H507 ◽  
Author(s):  
L. E. Ford
Keyword(s):  
Heart Rate ◽  
Body Weight ◽  
Metabolic Rate ◽  
Muscle Power ◽  
Weight Ratio ◽  
Single Species ◽  
Hill Climbing ◽  
Proper Size ◽  
Higher Power ◽  
Metabolic Indices

The question of the proper size denominator for metabolic indices is addressed. Metabolic rate among different species is proportional to the 3/4 power of body weight, not surface area. Muscle power also varies with the 3/4 power of weight, suggesting that metabolic rate is determined mainly by muscle power. Power-to-weight ratio, specific metabolic rate, and a number of metabolic periods, including heart rate, all vary inversely with the 1/4 power of body weight. Thus the relative times required for physiological and pathological processes in different species may be estimated from the average resting heart rate for the species. There are not many small humans among athletic record holders in events involving acceleration and hill climbing, as would be expected if they had higher power-to-weight ratios. Thus the relationship between size and metabolic rate in different species should not be applied within the single species of humans. Evidence is reviewed showing that basal metabolic rate in humans is determined mainly by lean body mass.

Respiratory Exchange and Body Size in the Aldabra Giant Tortoise

1971 ◽  
Vol 55 (3) ◽  
pp. 651-665 ◽  
Author(s):  
G. M. HUGHES ◽  
R. GAYMER ◽  
MARGARET MOORE ◽  
A. J. WOAKES
Keyword(s):  
Body Weight ◽  
Body Size ◽  
Metabolic Rate ◽  
Relative Proportion ◽  
The Body ◽  
O2 Consumption ◽  
Weight Range ◽  
Testudo Hermanni ◽  
The Mean ◽  
Good Agreement

1. The O2 consumption and CO2 release of nine giant tortoises Testudo gigantea (weight range 118 g-35·5 kg) were measured at a temperature of about 25·5°C. Four European tortoises Testudo hermanni (weight range 640 g-2·16 kg) were also used. The mean RQ values obtained were 1·01 for T. gigantea and 0·97 for T. hermanni. These values were not influenced by activity or size. 2. The data was analysed by plotting log/log regression lines relating body weight to O2 consumption. Both maximum and minimum metabolic rates recorded for each individual T. gigantea showed a negative correlation with body weight. For active rates the relation was O2 consumption = 140·8W0·97, whereas for inactive animals O2 consumption = 45·47W0·82. 3. The maximum rates were obtained from animals that were observed to be active in the respirometer and the minimum rates from animals that remained quiet throughout. The scope for activity increased with body size, being 82 ml/kg/h for animals of 100 g and 103 ml/kg/h for 100 kg animals. The corresponding ratio between maximum and minimum rates increases from about 2 to 6 for the same weight range. 4. Values for metabolic rate in T. hermanni seem to be rather lower than in T. gigantea. Analysis of the relative proportion of the shell and other organs indicates that the shell forms about 31% of the body weight in adult T. hermanni but only about 18% in T. gigantea of similar size. The shell is not appreciably heavier in adult T. gigantea (about 20%). 5. Data obtained for inactive animals is in good agreement with results of other workers using lizards and snakes. Previous evidence suggesting that chelonians show no reduction in metabolic rate with increasing size is not considered to conflict with data obtained in the present work.

Effect of Changes in Ambient Temperature on Spontaneous Activity, Food Intake and Body Weight of Goldthioglucose-Obese and Nonobese Mice

1957 ◽  
Vol 188 (3) ◽  
pp. 435-438 ◽  
Author(s):  
M. J. Fregly ◽  
N. B. Marshall ◽  
J. Mayer
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Ambient Temperature ◽  
The Body ◽  
Lower Body ◽  
Obese Mice ◽  
Ambient Temperatures ◽  
Exposure To Cold ◽  
Running Activity ◽  
Body Weights

Goldthioglucose-obese mice cannot adjust their food intake to meet the increased energy requirements due to cold. At all ambient temperatures above 15°C the spontaneous running activity of these animals is less than that observed for nonobese controls. Activity of obese mice is maximal at 19°C and minimal at 15°C or lower. Body weights decrease during exposure to cold. In contrast to that of obese mice, running activity of nonobese controls is maximal at an ambient temperature of 25°C but nearly ceases at 15°C or lower. The food intake of these animals increases in the cold and remains elevated even at temperatures at which activity decreases. The body weight of nonobese controls is either maintained constant or increases during exposure to cold air.

METABOLIC REFERENCE STANDARDS FOR THE NEONATE

PEDIATRICS ◽  
1967 ◽  
Vol 39 (5) ◽  
pp. 724-732
Author(s):  
John C. Sinclair ◽  
Jon W. Scopes ◽  
William A. Silverman
Keyword(s):  
Body Composition ◽  
Body Weight ◽  
Oxygen Consumption ◽  
Metabolic Rate ◽  
Extracellular Fluid ◽  
Mean Value ◽  
Reference Standards ◽  
Contributory Factor ◽  
Tissue Mass ◽  
Rate Of Oxygen Consumption

Oxygen consumption of 92 normally grown newborn babies of birth weight 750 to 3,940 gm has been expressed in terms of various metabolic reference standards in order to identify any systematic variation in expression of metabolic rate that is introduced by these bases of reference in the newborn population. It is postulated that differences in body composition comprise a contributory factor to the variation among newborn babies in rate of oxygen consumption per kilogram body weight. The predictive error from a mean value is increased if surface area, body weight, or fat-free body weight is substituted for body weight as a metabolic reference standard. By taking into account known changes in body composition of the fetus with increasing maturity, a compartment representing the active tissue mass is calculated. This corresponds closely to body weight minus extracellular fluid and includes fat. Rate of oxygen consumption is proportional to the size of this compartment over the range of body weights studied. Implications are discussed as to the metabolic rate of adipose tissue in the newborn and body composition among undergrown babies.

Thermoregulation of African and European Honeybees during Foraging, Attack, and Hive Exits and Returns

1979 ◽  
Vol 80 (1) ◽  
pp. 217-229 ◽  
Author(s):  
HEINRICH BERND
Keyword(s):  
Metabolic Rate ◽  
Ambient Temperature ◽  
Heat Loss ◽  
Warm Up ◽  
Ambient Temperatures ◽  
Thoracic Temperature

1. While foraging, attacking, or leaving or returning to their hives, both the African and European honeybees maintained their thoracic temperature at 30 °C or above, independent of ambient temperature from 7 to 23 °C (in shade). 2. Thoracic temperatures were not significantly different between African and European bees. 3. Thoracic temperatures were significantly different during different activities. Average thoracic temperatures (at ambient temperatures of 8–23 °C) were lowest (30 °C) in bees turning to the hive. They were 31–32 °C during foraging, and 36–38 °C in bees leaving the hive, and in those attacking. The bees thus warm up above their temperature in the hive (32 °C) before leaving the colony. 4. In the laboratory the bees (European) did not maintain the minimum thoracic temperature for continuous flight (27 °C) at 10 °C. When forced to remain in continuous flight for at least 2 min, thoracic temperature averaged 15 °C above ambient temperature from 15 to 25 °C, and was regulated only at high ambient temperatures (30–40 °C). 5. At ambient temperatures &gt; 25 °C, the bees heated up during return to the hive, attack and foraging above the thoracic temperatures they regulated at low ambient temperatures to near the temperatures they regulated during continuous flight. 6. In both African and European bees, attack behaviour and high thoracic temperature are correlated. 7. The data suggest that the bees regulate thoracic temperature by both behavioural and physiological means. It can be inferred that the African bees have a higher metabolic rate than the European, but their smaller size, which facilitates more rapid heat loss, results in similar thoracic temperatures.

Metabolic Rate of Female Rats as a Function of Age and Body Size

1956 ◽  
Vol 186 (1) ◽  
pp. 9-12 ◽  
Author(s):  
Max Kleiber ◽  
Arthur H. Smith ◽  
Theodore N. Chernikoff
Keyword(s):  
Body Weight ◽  
Body Size ◽  
Metabolic Rate ◽  
Age Groups ◽  
Female Rats ◽  
Standard Errors ◽  
Normal Female ◽  
Metabolic Rates ◽  
The Mean ◽  
Specific Unit

On the basis of 926 respiration trials, metabolic rates of normal female rats are presented as means of 42 different age groups from birth to 1000 days of age. The means with their standard errors are given for the metabolic rates per rat, per kilogram weight, per unit of the 2/3 power of body weight (surface), and per unit of the 3/4 power of body weight (inter specific unit of metabolic body size). A minimum of 72.6 Cal/kg.3/4 occurs between the ages of 200 and 300 days. An equation with two exponentials predicts the metabolic rate of rats from 77–1000 days of age with a standard deviation between prediction and observation of 2.2% of the mean.

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