scholarly journals Energy exchanges associated with eating and rumination in sheep given grass diets of different physical forms

1975 ◽  
Vol 34 (1) ◽  
pp. 59-71 ◽  
Author(s):  
P. O. Osuji ◽  
J. G. Gordon ◽  
A. J. F. Webster
Keyword(s):  
Heat Production ◽  
Energy Cost ◽  
Energy Requirement ◽  
Energy Costs ◽  
Heat Increment Of Feeding ◽  
Heat Increment ◽  
Energy Exchanges ◽  
The Mean ◽  
Preliminary Study ◽  
True Energy

1. Energy exchanges and other physiological functions associated with eating and rumination were determined in four experiments. Sheep were given chopped, dried grass (DGC), pelleted, dried grass (DGP) or fresh grass (FGC).2. In Expt 1 a preliminary study was made using all three diets. The dry matter (DM) of DGP was eaten significantly faster than that of chopped diets. Sheep salivated most during eating and ruminated longest when given DGC. Rates of contraction for the reticulo-rumen did not differ significantly between diets during idling and rumination, but were significantly faster during eating with DGP. The apparent energy costs of eating were 17, 109 and 176 kJ/kg DM eaten for DGP, DGC and FGC respectively, but these probably underestimated the true energy cost.3. Expt 2 compared DGP and DGC at two levels of intake. The mean energy costs of eating DGP and DGC were 23.5 and 267 kJ/kg DM respectively. There was no consistent relationship between the energy cost of eating and the duration of the meal. The proportion of time the sheep spent ruminating DGC was about 23% but less than 1% for DGP. There was no significant relationship between heat production and the time spent ruminating.4. In Expt 3 four sheep were offered fresh grass and, later, an equivalent DM intake after the material had been dried. The sheep ate the dried meal significantly faster. The mean energy costs of eating were 208 and 346 kJ/kg DM for DGC and FGC respectively. In this experiment the sheep ruminated significantly longer when given FGC, and the energy cost of rumination was 0.11 kJ/min.5. Increases in heat production during and after fistula-feeding were only 2–8% of those obtained during eating, indicating that nearly all the increase in heat production during eating could be attributed to the energy cost of eating per se.6. The contribution of the energy costs of eating and rumination to the heat increment of feeding and the energy requirement for maintenance of sheep are discussed.

Hormonal factors in reduced postprandial heat production of exercise-trained subjects

1984 ◽  
Vol 56 (3) ◽  
pp. 772-776 ◽  
Author(s):  
J. LeBlanc ◽  
P. Diamond ◽  
J. Cote ◽  
A. Labrie
Keyword(s):  
Exercise Training ◽  
Heat Production ◽  
Human Subjects ◽  
Resting Metabolic Rate ◽  
Glucose Disposal ◽  
Plasma Norepinephrine ◽  
Trained Subjects ◽  
Enhanced Sensitivity ◽  
Heat Increment Of Feeding ◽  
Heat Increment

The influence of exercise training on postprandial heat production was investigated in human subjects. Whereas resting metabolic rate was comparable for trained and nontrained subjects, the heat increment of feeding (HIF) after subjects consumed a meal containing 755 kcal was approximately 50% smaller in the trained subjects. Measurements of respiratory quotient also indicated a reduction of about 50% in glucose oxidation associated with exercise training. The levels of plasma norepinephrine increased significantly (P less than 0.01) from 200 to 300 pg/ml in the sedentary subjects, but the changes observed in trained subjects were not significant. During the early phase of the meal, plasma levels of insulin were increased, even before nutrients appeared in the blood. Throughout the study the enhanced sensitivity to insulin of the trained subjects was confirmed. the postprandial heat production was diminished in exercise-trained subjects, and it is suggested that this could be related to a reduced activity of the sympathetic nervous system. Another possibility is that this reduction in HIF is related to a facilitation of glucose disposal in the form of glycogen rather than in the form of lipids.

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.

Activity and energy expenditure in laying hens: 3. The energy cost of eating and posture

1976 ◽  
Vol 87 (1) ◽  
pp. 85-88 ◽  
Author(s):  
M. Van Kampen
Keyword(s):  
Energy Expenditure ◽  
Spontaneous Activity ◽  
Heat Production ◽  
Energy Cost ◽  
Laying Hens ◽  
The Mean ◽  
Per Se ◽  
The Difference

SummaryThe influence of standing, spontaneous activity and eating on heat production was determined.The extra heat production of standing is negatively correlated with the length of standing period. In a short standing period of 30 min the associated activity, pecking against the respirometer wall and fluffing the feathers, was high and the heat production was increased by 25% compared with that during sitting. After standing for 1½ h spontaneous activity was very low and the difference in heat production between the standing and sitting bird was reduced by 9%.During eating the heat production increased by an average of 37% (range 11–68%); this was due mainly to the act of eating per se and not to the work of digestion.The mean energy cost of eating was calculated to be 143 J/kg0·75/min spent eating.

Energy cost of eating long hay, straw and pelleted food in sport horses

1995 ◽  
Vol 61 (3) ◽  
pp. 581-588 ◽  
Author(s):  
J. Vernet ◽  
M. Vermorel ◽  
W. Martin-Rosset
Keyword(s):  
Wheat Straw ◽  
Energy Cost ◽  
Dry Matter ◽  
Energy Requirement ◽  
Ingestion Rate ◽  
Open Circuit ◽  
Metabolizable Energy ◽  
Long Form ◽  
The Mean ◽  
The Difference

AbstractSix sport horses were given 1·26 times the measured maintenance energy requirement (MEm) from each of the four following diets: H1, meadow hay in the long form (organic matter digestibility OMD = 0·541); HMI, 700g/kg the same hay and 300 g/kg pelleted maize; HSBPI, 600g/kg hay and 400g/kg pelleted dehydrated sugar-beet pulp; SCFI, 500g/kg wheat straw and 500g/kg pelleted compound food (experiment 1). In experiment 2, eight sport horses were equipped with a portable device for recording feeding behaviour and fed at 1·31 MEm diet HI (meadow hay in the long form: OMD = 0·574).Circadian energy expenditure (EE) of horses was determined by indirect calorimetry using two large open-circuit respiration chambers. Horses were continuously standing. Increase in metabolic rate (IMR) during eating was calculated from the difference between the mean EE obtained during each eatingperiod and the corresponding resting EE. The mean daily ingestion rate of hay H2 amounted to 148 (s.d. 27)mg dry matter per kg metabolic body weight per min. IMR during the two main meals averaged 0·388 (s.d. 0·059) and was not significantly different between diets H1, H2, HM1 and SCF1. Expressed per kg dry matter intake, energy cost of eating (ECE) was similar for diets H2, H1 and SCF1 but significantly lower for HSBP1 and HM1 (P<0·05). ECE of simple foods was calculated from those of the diets and of hay: proportionately 0·010, 0·042, 0·102 and 0·285 metabolizable energy intake for pelleted maize, pelleted SBP, long hay and wheat straw, respectively.

scholarly journals Estimation of the energy costs of locomotion in the Iberian pig(Sus mediterraneus)

2000 ◽  
Vol 83 (1) ◽  
pp. 35-41 ◽  
Author(s):  
M. Lachica ◽  
J. F. Aguilera
Keyword(s):  
Heat Production ◽  
Energy Cost ◽  
Live Weight ◽  
Energy Costs ◽  
Net Energy ◽  
Mean Values ◽  
A Value ◽  
Cost Of Locomotion ◽  
Iberian Pig ◽  
Energy Cost Of Locomotion

The energy cost of locomotion of four Iberian pigs was measured in two experiments conducted when the animals averaged 41·3 (se 0·1) kg (first experiment) and 84·1 (se 0·1) kg (second experiment). The heat production of the pigs was determined when standing or walking at a speed of 0·555 m/s on a treadmill enclosed in a confinement-type respiration chamber, on different slopes (-10·5, 0, and +10·5 % in the first experiment, and -5·25, 0 and +10·5 % in the second experiment). The energy costs of locomotion, estimated from the coefficients of linear regressions of heat production per kg body weight (BW) on distance travelled, were in the first experiment 2·99, 3·31 and 5·88 J/kg BW per m for -10·5, 0, and +10·5 % inclines respectively, and 2·56, 2·84 and 7·13 J/kg BW per m for -5·25, 0 and +10·5 % inclines respectively, in the second experiment. The net energy cost of locomotion on the level appeared to be independent of live weight, attaining a value of 2·98 J/kg BW per m. Also, it was found that within experiments the net energy cost of walking on negative slopes was similar to that for locomotion on the level, indicating that no energy was recovered on vertical descent. Mean values were 3·11 and 2·72 kJ/kg BW per m for the light and heavy pigs respectively. The energy cost of raising 1 kg BW one vertical metre was found to be 27·1 J/kg BW per m in the first experiment and 40·0 J/kg BW per m in the second experiment. Correspondingly, the calculated efficiency for upslope locomotion appeared to decline with increasing BW, resulting in average values of 36·2 and 24·5 %.

scholarly journals Juvenile salmon with high standard metabolic rates have higher energy costs but can process meals faster

2009 ◽  
Vol 276 (1664) ◽  
pp. 2103-2108 ◽  
Author(s):  
K.J. Millidine ◽  
J.D. Armstrong ◽  
N.B. Metcalfe
Keyword(s):  
Salmo Salar ◽  
Assimilation Efficiency ◽  
High Standard ◽  
Standard Metabolic Rate ◽  
Specific Dynamic Action ◽  
Total Energy Expenditure ◽  
Feeding Strategies ◽  
Energy Costs ◽  
Heat Increment Of Feeding ◽  
Heat Increment

Basal or standard metabolic rate (SMR) has been found to exhibit substantial intraspecific variation in a range of taxa, but the consequences of this variation are little understood. Here we explore how SMR is related to the energy cost of processing food, known as apparent specific dynamic action or the heat increment of feeding. Using juvenile Atlantic salmon Salmo salar , we show that fishes with a higher SMR had a higher peak and a greater total energy expenditure when digesting a given size of meal. However, the duration over which their metabolism was elevated after consuming the meal was shorter. The greater energy costs they incur for processing food may be related to their assimilation efficiency. These relationships are likely to have implications for feeding strategies and growth rates, since individuals with a higher SMR have higher routine costs of living but recover more quickly following feeding and so may have a greater potential for processing food.

Temporal responses in energy expenditure and respiratory quotient following feeding in the muskox: influence of season on energy costs of eating and standing and an endogenous heat increment

2003 ◽  
Vol 81 (9) ◽  
pp. 1524-1538 ◽  
Author(s):  
James P Lawler ◽  
Robert G White
Keyword(s):  
Energy Expenditure ◽  
Energy Cost ◽  
Low Cost ◽  
Exponential Process ◽  
Ovibos Moschatus ◽  
Post Feeding ◽  
Double Exponential ◽  
Heat Increment ◽  
The Mean ◽  
Maintenance Metabolism

Seasonal energy metabolism was investigated in young (2- to 3-year-old) muskoxen (Ovibos moschatus) during the winters of 1994 (January–April) and 1996 (January) and summer of 1995 (July and August). Energy expenditure (EE) increased 35%–42% following a meal of chopped brome hay (Bromus inermis) and declined as a double-exponential process over 8 h. The mean energy cost of eating (321 and 361 J·g dry matter–1) was lower in winter than in summer, and declined with body mass (BM) (r2 = 0.58). The mean energy cost of standing was 21% (SE = 2.7%) higher than that of bedding. Prefeeding energy expenditure (EEp) was 26% higher in summer than in winter. An endo genous heat increment, measured as EEp – EE, at 7-8 h post feeding was lower (P < 0.001) in winter than in summer (39 and 58 kJ·kg BM–0.75·d–1, respectively). Mean cumulative EE (minus activity costs) for 8 h post feeding was 124 (SE = 4) and 148 (SE = 4) kJ·kg BM–0.75 (P < 0.001) in winter and summer, respectively. Respiratory quotients (RQs) >1 were recorded during feeding in winter and a mean RQ of 0.9 was recorded in summer. Seasonal EEp, postfeeding EE, and RQ are consistent with a low cost of maintenance metabolism in winter and an increased requirement for productivity in summer.

scholarly journals Dynamics of the Ice-Crushing Process

1988 ◽  
Vol 34 (118) ◽  
pp. 318-326 ◽  
Author(s):  
Ian J. Jordaan ◽  
Garry W. Timco
Keyword(s):  
Ice Sheet ◽  
Load Cycle ◽  
Stored Energy ◽  
Indentation Process ◽  
Ice Particles ◽  
Mode Of Failure ◽  
Indentation Tests ◽  
Energy Exchanges ◽  
The Mean ◽  
Crushed Ice

Abstract During fast indentation tests on ice sheets at constant rates, crushing is commonly observed at appropriate combinations of speed and aspect ratio. An analysis is made of this mode of failure, using as a basis a recently conducted test on an ice sheet under controlled conditions. The variation of load with time is given special attention, and cyclic variation of load is associated with periodic crushing (pulverization) events, followed by clearing of the crushed ice particles. An analysis of the clearing process is summarized in the paper, treating the crushed ice as a viscous material. A detailed analysis of the energy exchanges during the indentation process is given. Elastic variations of stored energy in the indenter and in the ice sheet are calculated; these are relatively minor. The dissipation of energy during a typical load cycle (3 mm movement during 0.05 s) is about 8 J. The energy required to create surfaces of the crushed ice particles is small (0.006 J), as is the work of crushing based on mechanical testing (0.09 J). It is concluded that the process of viscous extrusion of crushed ice is the main seat of energy dissipation, basically as a frictional process. A relationship for the mean thickness of the crushed ice layer is developed, based on energy-balance considerations.

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