Postprandial heat increment does not substitute for active thermogenesis in cold-challenged star-nosed moles (Condylura cristata)

2000 ◽  
Vol 203 (2) ◽  
pp. 301-310 ◽  
Author(s):  
K.L. Campbell ◽  
I.W. McIntyre ◽  
R.A. MacArthur
Keyword(s):  
Metabolic Rate ◽  
Heat Production ◽  
Metabolizable Energy ◽  
Acid Oxidation ◽  
Long Term Effects ◽  
Passage Rate ◽  
Food Energy ◽  
Air Temperatures ◽  
Heat Increment ◽  
Condylura Cristata

The postprandial increase in metabolic rate associated with consuming, assimilating and excreting a meal is often termed the heat increment of feeding (HIF). The metabolic heat production of star-nosed moles, Condylura cristata, held at thermoneutrality was monitored for 4 h following a single 10 min session of feeding on a ration consisting of 0 g (controls), 3.5 g or 10 g of earthworms. Coefficients for metabolizable energy digestibility and digesta passage rate of earthworms fed to C. cristata were also determined. We then tested whether feeding-induced thermogenesis substitutes partially or completely for thermoregulatory heat production in these animals exposed to sub-thermoneutral air temperatures (9–24 degrees C). A single feeding on earthworms had both short- and long-term effects on the metabolic rate and respiratory exchange ratio of C. cristata. The observed short-term (0–65 min) rise in metabolic rate, assumed to be associated primarily with the physical costs of nutrient digestion, absorption and excretion, was similar to the calculated mean retention time (66.7+/−7.8 min; mean +/− s.e. m., N=5) of this species. This component of the HIF represented 2.9 % of the food energy ingested by moles fed a single 3.5 g (13.21 kJ) meal of earthworms and 1.4 % of the food energy ingested by moles fed a single 7.5 g (28.09 kJ) meal of earthworms. At all test temperatures, resting metabolic rate typically remained above fasting levels for 1–4 h following ingestion of the high-protein earthworm diet. This protracted rise in metabolic rate, presumably associated with the biochemical costs of amino acid oxidation/gluconeogenesis and ureagenesis, averaged 12.8 % of the metabolizable energy and 8.7 % of the gross energy intake. Despite the potential thermoregulatory benefit, we found no evidence that biochemical HIF substitutes for facultative thermogenesis in star-nosed moles exposed to low air temperatures.

Metabolic Factors in the Development of Homeothermy in Dogs

1958 ◽  
Vol 194 (2) ◽  
pp. 293-296 ◽  
Author(s):  
Donald G. McIntyre ◽  
H. E. Ederstrom
Keyword(s):  
Oxygen Consumption ◽  
Metabolic Rate ◽  
Rectal Temperature ◽  
Heat Production ◽  
Cold Exposure ◽  
Metabolic Factors ◽  
Air Temperatures ◽  
Heat Conservation

Dogs from 1 to 25 days of age were exposed to air temperatures of 5, 23 and 30°C and their oxygen consumption measured in a closed calorimeter. Animals 1–5 days old had a rise of 20–25% in metabolic rate, but rectal temperature fell, when they were exposed to 5 or 23°C. At 11–21 days of age dogs exposed to 5°C had a rise of about 75% in metabolic rate, but rectal temperature fell several degrees in 1 hour. In dogs 21–25 days of age metabolic rate increased about 75% at air temperatures of 5°C and rectal temperature fell only about 1°C. Under the same conditions a trained adult dog had a rise of 80% in metabolic rate, and no fall in rectal temperature. Since heat production in 2- to 3-week-old dogs was increased to about the same extent as in the adult on cold exposure, it was assumed that heat conservation lagged behind heat production in the development of homeothermy.

Compensatory effect of the heat increment of feeding on thermoregulation costs of white-tailed deer fawns in winter

1999 ◽  
Vol 77 (9) ◽  
pp. 1474-1485 ◽  
Author(s):  
Paul G Jensen ◽  
Peter J Pekins ◽  
James B Holter
Keyword(s):  
Metabolic Rate ◽  
Heat Production ◽  
Resting Metabolic Rate ◽  
Energetic Cost ◽  
Critical Temperatures ◽  
Metabolic Chamber ◽  
Heat Increment Of Feeding ◽  
Heat Increment ◽  
Minor Portion ◽  
A Minor

For northern white-tailed deer (Odocoileus virginianus) fawns, the energetic cost of thermoregulation (HcE) during severe winters can result in substantial catabolism of body-tissue reserves. The heat increment of feeding (HiE) has the potential to offset thermoregulatory energy expenditure that would otherwise require the catabolism of these reserves. During winters 1996 and 1997, we conducted 18 fasting and 18 on-feed heat-production trials using indirect respiration calorimetry in a metabolic chamber. Nonlinear regression analysis was used to estimate the lower critical temperatures (Tlc) and determine the fasting metabolic rate (FMR) and resting metabolic rate (RMR). Resulting models were used to calculate HiE, HcE, and percent substitution of HiE for HcE. For fawns fed a natural browse diet, estimated FMR and RMR were 352 and 490 kJ·kg body mass (BM)-0.75·d-1, respectively; this 40% increase in thermoneutral heat production reduced Tlc from -0.8 to -11.2°C between the fasted and fed states, respectively, and reduced HcE by 59% for fed fawns. For fawns fed a concentrate diet, estimated FMR and RMR were 377 and 573 kJ·kg BM-0.75·d-1, respectively. Level of browse intake had a significant effect on RMR andTlc. RMR was 12% higher for fawns on a high versus a low level of intake, and estimated Tlc was -15.6 and -5.8°C, respectively. Our data indicate that the energetic cost of thermoregulation is probably a minor portion of the energy budget of a healthy fawn consuming natural forage.

Energy exchanges of pregnant and lactating ewes

1964 ◽  
Vol 15 (1) ◽  
pp. 127 ◽  
Author(s):  
N McCGraham
Keyword(s):  
Heat Production ◽  
Nitrogen Loss ◽  
Metabolizable Energy ◽  
Energy Utilization ◽  
Carbon And Nitrogen ◽  
Direct Measurements ◽  
Heat Increment ◽  
Energy Retention ◽  
Energy Exchanges ◽  
Pregnant Ewe

At intervals throughout gestation, the energy, carbon, and nitrogen exchanges of four Merino ewes were determined with the aid of closed-circuit indirect calorimetry. Six similar but non-pregnant animals were studied at the same time. The food consisted of equal parts of lucerne and wheaten hay; half the sheep in each group were given a constant 600 g/day and half 900 g/day, and the non-pregnant ewes were fasted on one occasion. Free fatty acids, glucose, and ketones in the blood were also determined during the final stages of pregnancy. Balance measurements were continued during lactation, the ewes being given 1200 g food/day for the first month and 900 g for the second. The digestibility of the food was not affected by pregnancy or lactation, but urinary nitrogen loss decreased as pregnancy advanced and was least during lactation. Although a constant amount of food was eaten, the heat production of each pregnant animal increased throughout gestation. The heat increment of pregnancy at term was 90 kca1/24 hr/kg foetal tissue. The most direct measurements of oxygen uptake by the foetus in utero indicate much lower levels of heat production per kilogram of tissue; it is concluded that these are underestimates. The metabolic rate was unusually high immediately before parturition, and in two cases decreased to near non-pregnant levels 24 hr after lambing. The total energy retention of the ewes became smaller as pregnancy advanced, and in two cases was negative at term. Metabolizable energy was used for reproduction with a gross efficiency of 15–22% and a net efficiency of 13%. The metabolizable energy used per kilogram of foetus was approximately 10% of the maintenance requirement of the ewe herself. Daily energy utilization by the conceptus at term probably accounted for 70% of the glucogenic substances available from the food. There was no evidence of increased gluconeogenesis from protein by the pregnant ewe. The nutrition of the ewe during gestation affected lactation mainly in the first week or two. The data indicate that nitrogen intake rather than energy intake limited milk production. Irrespective of the amount of energy in the milk, the heat increment due to feeding was 20% smaller for lactating than for dry fatteningewes. It is suggested that efficient use of acetate by the mammary gland permits more efficient lipogenesis by other tissues.

Calorimetric studies on the effect of dietary energy source and environmental temperature on the metabolic efficiency of energy utilization by mature Light Sussex cockerels

1969 ◽  
Vol 72 (3) ◽  
pp. 479-489 ◽  
Author(s):  
D. W. F. Shannon ◽  
W. O. Brown
Keyword(s):  
Heat Production ◽  
Environmental Temperature ◽  
Metabolizable Energy ◽  
Energy Utilization ◽  
Metabolic Efficiency ◽  
Heat Increment ◽  
Energy Retention ◽  
Calorimetric Studies ◽  
The Relationship ◽  
Maize Oil

SUMMARYExperiments to determine the net availabilities of the metabolizable energy (NAME) of a cereal-based diet and a maize-oil diet for maintenance and lipogenesis and the effect of environmental temperature on the NAME of the cereal-based diet are described. Four 1- to 2-year-old Light Sussex cockerels were used.The relationship between ME intake and energy retention was linear for each diet. The NAME'S of the cereal-based diet given at 22° and 28 °C (70.6 ± 1.83 % and 73.6 ± 3.54%, respectively) were significantly (P < 0.05) lower than the NAME of the maize-oil diet (84.1 ± 1.85%). It is concluded that the beneficial effect of maize oil on the efficiency of energy utilization is due to a reduced heat increment rather than a reduction in the basal component of the heat production. The higher efficiency from the maize-oil diet led to an increase in the energy retained as fat.The mean fasting heat production at 28 °C was 15 % lower than at 22 °C (43.2 ± 1.45 and 51.2 ± 1.09 kcal/kg/day, respectively). The NAME of the cereal-based diet was not significantly different when the birds were kept at 22° or 28 °C. The lower metabolic rate at 28 °C was reflected in a lower maintenance requirement and in an increase in the deposition of body fat.

Influence of ambient temperatures on the heat production of pregnant ewes

1964 ◽  
Vol 15 (6) ◽  
pp. 982 ◽  
Author(s):  
N McCGraham
Keyword(s):  
Critical Temperature ◽  
Heat Production ◽  
Fatty Acid Content ◽  
Plasma Free Fatty Acid ◽  
Metabolizable Energy ◽  
Critical Temperatures ◽  
Blood Constituents ◽  
Ambient Temperatures ◽  
Heat Increment ◽  
Urinary Nitrogen

Two Merino ewes were kept on constant diets throughout pregnancy and, after shearing, were exposed to a series of ambient temperatures between 10 and 35°C on several occasions before lambing and once afterwards. Their heat production and urinary nitrogen output were determined at each temperature, and some blood constituents were also measured. Metabolizable energy intakes were 1300 and 1900 kcal/day. The estimated critical temperatures (minimal heat production) of the sheep ranged from 28 to 35°C, being lower at the higher level of feeding and also during pregnancy. A general relationship between thermoneutral heat production per sq. metre and the critical temperature of shorn sheep was derived; the heat increments of gestation and feeding merely increase thermoneutral heat production and so decrease the critical temperature. The heat increment of gestation was 80 and 90 kcal/24 hr/kg lamb at the high and low feeding levels respectively. Fat oxidation (as indicated by the respiratory quotient) and heat production increased up to twofold at subcritical temperatures. At 10°C there was no heat increment due to pregnancy or feeding; blood glucose was increased by 6–9 mg/100 ml in one sheep, and plasma free fatty acid content was highest at 10° in both sheep (0.9 m-equiv./l.). Heat production also tended to be elevated at the highest temperature. The change was greatest (8%) during pregnancy and at the higher level of feeding. Urinary nitrogen increased at the same time only when the sheep were not pregnant. Improved nitrogen economy during gestation was also apparent at other temperatures.

scholarly journals The effect of ambient temperature and activity on the daily variation in heat production of growing pigs kept in groups.

1986 ◽  
Vol 34 (2) ◽  
pp. 173-184
Author(s):  
W. van der Hel ◽  
R. Duijghuisen ◽  
M.W.A. Verstegen
Keyword(s):  
Metabolic Rate ◽  
Ambient Temperature ◽  
Heat Production ◽  
Temperature Treatment ◽  
Time Of Day ◽  
Growing Pigs ◽  
Metabolizable Energy ◽  
Adaptation Period ◽  
Before And After ◽  
Lower Temperature

In two experiments, pigs with initial weights of 20 kg were kept in climate-controlled respiration chambers. After a 7-day adaptation period at 22-24 degrees C the temperature was reduced in 4 degrees C steps to 8 degrees C and then increased to 24 degrees C. Each temperature treatment lasted 3 days. Feed contained 12 kJ metabolizable energy per g and was given at 93 and 83 g/kg0.75 per day in experiments 1 and 2, respectively. Lower temperature increased 24 h heat production, but not 24 h activity. The mean activity periods moved from before and after feeding to after feeding, especially in the afternoon. During the afternoon, activity decreased at the lower ambient temperature, whereas metabolic rate remained constant. It is concluded that the effect of ambient temperature on metabolic rate depends on the time of day. (Abstract retrieved from CAB Abstracts by CABI’s permission)

The relationship between the rate of heat production and the level of milk production in a subtropical climate

1963 ◽  
Vol 14 (6) ◽  
pp. 874 ◽  
Author(s):  
A Berman ◽  
S Amir ◽  
R Volcani
Keyword(s):  
Heat Production ◽  
Feed Intake ◽  
Open Circuit ◽  
Subtropical Climate ◽  
Air Temperatures ◽  
Hourly Rate ◽  
Heat Increment ◽  
Heat Requirements ◽  
Ad Libitum ◽  
The Relationship

Heat production as determined by the open circuit mask method, thermoregulatory responses, fat-corrected milk (F.C.M.) yield, and feed intake were recorded in two groups of 11 Israeli-Holstein cows each from the seventh day after calving up to 104 days of lactation. One group was fed according to the Fredricksen standard and the other group ad libitum, its feed intake being 125% of the Fredricksen standard. The experiment was carried out from January to mid July. No apparent heat increment of lactation was observed in the group fed according to the Fredricksen standard. A highly significant heat increment was found (10.3 kcal/hr/kg F.C.M.) at lower air temperatures (16–22°C) in the group fed ad libitum, while at higher air temperatures (23–28°C) a smaller, non-significant heat increment (5.4 kcal/hr/kg F.C.M.) was found. The hourly rate of heat production, the rectal temperature, respiration rate, respiratory volume, and respiratory vaporization changed only by small non-significant amounts with increasing temperatures. From these data it is inferred that heat production did not increase above heat requirements, except for the group fed ad libitum during the period at lower temperatures. This is explained by an increase in the critical temperature of the animals through a gradual adaptation to the summer conditions. This adaptation involves a decreased peripheral insulation by the summer coat and a lower basal metabolic rate. It is , suggested that these adaptational processes occurring in nature should be considered in studies on heat increments of feeding and of lactation.

scholarly journals What is the digestibility and caloric value of different botanical parts in corn residue to cattle?1

2019 ◽  
Vol 97 (7) ◽  
pp. 3056-3070 ◽  
Author(s):  
Emily A Petzel ◽  
Evan C Titgemeyer ◽  
Alexander J Smart ◽  
Kristin E Hales ◽  
Andrew P Foote ◽  
...  
Keyword(s):  
Organic Matter ◽  
Nutrient Availability ◽  
Heat Production ◽  
Latin Square ◽  
Metabolizable Energy ◽  
Net Energy ◽  
Digestible Energy ◽  
Randomized Design ◽  
Corn Residue ◽  
Completely Randomized Design

AbstractTwo experiments were conducted to measure rates of ruminal disappearance, and energy and nutrient availability and N balance among cows fed corn husks, leaves, or stalks. Ruminal disappearance was estimated after incubation of polyester bags containing husks, leaves or stalks in 2 separate ruminally cannulated cows in a completely randomized design. Organic matter (OM) that initially disappeared was greatest for stalks and least for husks and leaves (P < 0.01), but amounts of NDF that initially disappeared was greatest for husks, intermediate for stalks, and least for leaves (P < 0.01). Amounts of DM and OM that slowly disappeared were greatest in husks, intermediate in leaves, and least in stalks (P < 0.01). However, amounts of NDF that slowly disappeared were greatest in leaves, intermediate in husks, and least in stalks (P < 0.01). Rate of DM and OM disappearance was greater for leaves, intermediate for husks and least for stalks, but rate of NDF disappearance was greatest for stalks, intermediate for leaves, and least for husks (P < 0.01). Energy and nutrient availability in husks, leaves, or stalks were measured by feeding ruminally cannulated cows husk-, leaf-, or stalk-based diets in a replicated Latin square. Digestible energy lost as methane was less (P = 0.02) when cows were fed leaves in comparison to husks or stalks, and metabolizable energy (Mcal/kg DM) was greater (P = 0.03) when cows were fed husks and leaves compared with stalks. Heat production (Mcal/d) was not different (P = 0.74) between husks, leaves, or stalks; however, amounts of heat produced as a proportion of digestible energy intake were less (P = 0.05) among cows fed leaves in comparison to stalks or husks. Subsequently, there was a tendency (P = 0.06) for net energy available for maintenance from leaves (1.42 Mcal/kg DM) to be greater than stalks (0.91 Mcal/kg DM), and husks (1.30 Mcal/kg DM) were intermediate. Nitrogen balance was greater when cows were fed leaves, intermediate for husks, and least for stalks (P = 0.01). Total tract digestion of NDF was greater (P < 0.01) for husks and leaves compared with stalks. Husks had greater (P = 0.04) OM digestibility in comparison to stalks, and leaves were intermediate. Apparently, greater production of methane from husks in comparison to leaves limited amounts of energy available for maintenance from husks even though total-tract nutrient digestion was greatest when cows were fed husks or leaves.

Effect of Diethylstilbestrol on Utilization of Energy by the Growing Chick

1958 ◽  
Vol 195 (3) ◽  
pp. 654-658 ◽  
Author(s):  
F. W. Hill ◽  
L. B. Carew ◽  
A. van Tienhoven
Keyword(s):  
Energy Consumption ◽  
Linear Function ◽  
Heat Production ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Energy Yield ◽  
Net Energy ◽  
Lower Protein ◽  
Energy Gains ◽  
Total Tissue

Increased fat production in diethylstilbestrol-treated chicks was found to be due primarily to increased energy consumption and to a lesser extent to preferential synthesis of fat at the expense of protein tissue. This was shown in experiments comparing normal and estrogen-treated male chicks with respect to gains in live weight, fat and protein at two planes of nutrition, and the yield of metabolizable and productive (net) energy which they obtained from the diet. It was found that the fattening effect could not be due to increased digestibility, increased net energy yield from absorbed nutrients, or lowered heat production. Under the influence of estrogen, total tissue gain expressed in Calories was increased, and was composed of greater fat gain and lower protein gain. Tissue energy gains were a linear function of metabolizable energy consumption. This relationship predicted equal tissue energy gains under pair-feeding conditions, which was confirmed experimentally.

Physical fitness and thermoregulatory reactions in a cold environment in men

1988 ◽  
Vol 65 (5) ◽  
pp. 1984-1989 ◽  
Author(s):  
J. H. Bittel ◽  
C. Nonotte-Varly ◽  
G. H. Livecchi-Gonnot ◽  
G. L. Savourey ◽  
A. M. Hanniquet
Keyword(s):  
Physical Fitness ◽  
Cold Stress ◽  
Heat Production ◽  
Ambient Air ◽  
Metabolic Heat Production ◽  
Adult Males ◽  
Fitness Level ◽  
Metabolic Heat ◽  
Air Temperatures ◽  
Thermoregulatory Reactions

The relationship between the physical fitness level (maximal O2 consumption, VO2max) and thermoregulatory reactions was studied in 17 adult males submitted to an acute cold exposure. Standard cold tests were performed in nude subjects, lying for 2 h in a climatic chamber at three ambient air temperatures (10, 5, and 1 degrees C). The level of physical fitness conditioned the intensity of thermoregulatory reactions to cold. For all subjects, there was a direct relationship between physical fitness and 1) metabolic heat production, 2) level of mean skin temperature (Tsk), 3) level of skin conductance, and 4) level of Tsk at the onset of shivering. The predominance of thermogenic or insulative reactions depended on the intensity of the cold stress: insulative reactions were preferential at 10 degrees C, or even at 5 degrees C, whereas colder ambient temperature (1 degree C) triggered metabolic heat production abilities, which were closely related to the subject's physical fitness level. Fit subjects have more efficient thermoregulatory abilities against cold stress than unfit subjects, certainly because of an improved sensitivity of the thermoregulatory system.

Sign in / Sign up

Export Citation Format

Share Document