scholarly journals Dynamic aspects of oxygen consumption and carbon dioxide production in swine

1997 ◽  
Vol 78 (3) ◽  
pp. 397-410 ◽  
Author(s):  
J. Van Milgen ◽  
J. Noblet ◽  
S. Dubois ◽  
J.-F. Bernier
Keyword(s):  
Differential Equations ◽  
Heat Production ◽  
Carbon Dioxide Production ◽  
Measurement Range ◽  
Open Circuit ◽  
Growing Pigs ◽  
Model Parameters ◽  
Respiration Chamber ◽  
Gas Exchanges ◽  
Animal Metabolism

A model is proposed that allows study of the short-term dynamics of gas exchanges (and heat production) in large open-circuit respiration chambers. The model describes changes in [O2] and [CO2] in the respiration chamber by a series of differential equations based on animal metabolism and physical characteristics of gas exchange. The model structure was similar for O2 and CO2, although model parameters differed. A constant level of O2 consumption (and CO2 production) was assumed for resting animals which was different for fed and fasted animals. The adaptation from a fed to a fasting state was described as a first-order process. Physical activity (standing or sitting) was recorded and was included in the model as a constant. Thermic effect of feed comprised the O2 consumption and CO2 production related to several relatively rapidly occurring processes after ingestion of a meal (e.g. ingestion, digestion or absorption). In the model, these processes were pooled into a single phenomenon. Model parameters were obtained statistically by comparing model predictions (based on the numerically integrated differential equations) with the observed [O2] and [CO2]. The model was evaluated by studying gas exchanges in growing pigs that were fasted for 31 h and re-fed a single meal thereafter. The model fitted the data well over the 47 h measurement range. Traditional methods in which heat production is calculated suffer from noisy data when the interval between observations becomes too short. The proposed method circumvents this by modelling the observed concentration of gases in the respiration chamber rather than the calculated heat production.

scholarly journals The energy cost of standing and lying in adult cattle

1973 ◽  
Vol 30 (2) ◽  
pp. 207-210 ◽  
Author(s):  
J. E. Vercoe
Keyword(s):  
Heat Production ◽  
Energy Cost ◽  
Fast Response ◽  
Short Term ◽  
Time Intervals ◽  
Adult Cattle ◽  
Respiration Chamber ◽  
Gas Exchanges ◽  
The Difference ◽  
Over Time

1. Gas exchanges on eleven steers with a mean weight of 273 kg, fasted for 96 h, were obtained over time intervals of 5·76 min in a confinement-type respiration chamber, when the animals were either standing of lying, or engaged in the act of standing or lying.2. In all, 751 observations were analysed and these included twenty-four associated with the act of standing, forty-eight with the act of lying and the remainder approximately equally divided between standing and lying.3. When lying, the heat production was 72·2 kJ (17·2 kcal)/kg fasted weight per 24 h and when standing, 85·7 kJ (20·5 kcal)/kg fasted weight per 24 h; an increase when standing of 18·7%. The double act of standing and lying was associated with an increase in heat production of 11·3 kJ (2·7 kcal)/100 kg fasted weight and while the act of standing was energetically more costly than the act of lying, the difference between the two was not significant.4. The results are discussed in relation to earlier estimates.5. Confinement-type respiration chambers of the type described by Turner & Thornton (1966), which have a fast response time and monitor the changes in chamber air frequently, are ideally suited to the detection of short-term changes in metabolic rate such as occur with changes in posture.

Further studies on the heat production and effective lower critical temperature of early-weaned pigs under commercial conditions of feeding and management

1984 ◽  
Vol 39 (2) ◽  
pp. 283-290 ◽  
Author(s):  
K. J. McCracken ◽  
R. Gray
Keyword(s):  
Critical Temperature ◽  
Heat Production ◽  
Thermal Conductance ◽  
Open Circuit ◽  
Weaned Pigs ◽  
Respiration Chamber ◽  
Lower Critical Temperature ◽  
The Mean ◽  
The Difference ◽  
Practical Implications

ABSTRACTIn two separate experiments pigs were weaned at 14 or 28 days and heat production was determined in an open-circuit respiration chamber at temperatures above and below the lower critical temperature (Tcl) at intervals during the post-weaning period.With 14-day weaned pigs the mean 24 h heat production above Tc1 averaged 267, 328, 474 and 554 kJ/h per m2 at 3, 9, 15 and 21 days post weaning respectively. The mean thermal conductance (H/AT, kJ/h per m2 per °ΔT, where H is total heat production, m2 is the surface area calculated as 0·097 M kg0·633 and °Δ is the difference between rectal temperature, taken at 39°, and air temperature) below TC1 was calculated as 20·5, 20·1, 23·1 and 24·2 at 17, 23, 29 and 35 days of age respectively and the corresponding values for Tc1 were 25·9, 23·0, 18·4 and 16·0°C.With 28-day weaned pigs the mean 24 h heat production above Tc1 averaged 280, 361 and 445 kJ/h per m2 at 3, 9 and 15 days post weaning. The calculated values for H/ΔT were 19·7, 20·8 and 21·6 and the corresponding values of Tcl were 24·8, 21·7, and 18·8°C at 31, 37 and 43 days of age respectively.The results are discussed in relation to previous studies on 10-day and 28-day weaned pigs and in relation to the practical implications for pigs weaned into controlled-environment accommodation.

scholarly journals Studies on diurnal variations of heat production and the effective lower critical temperature of early-weaned pigs under commercial conditions of feeding and management

1980 ◽  
Vol 43 (2) ◽  
pp. 321-328 ◽  
Author(s):  
K. J. McCracken ◽  
B. J. Caldwell
Keyword(s):  
Critical Temperature ◽  
Heat Production ◽  
Thermal Conductance ◽  
Open Circuit ◽  
Respiration Chamber ◽  
Mean Values ◽  
Maximum Value ◽  
Lower Critical Temperature ◽  
The Mean ◽  
The Difference

1. The heat production of groups of pigs, weaned at 10 d of age, was determined in an open-circuit respiration chamber at various ages between 10 and 33 d at temperatures above and below the lower critical temperature (Tcl).2. The heat production was lowest on the second or third day post weaning when pigs were given feed increasing by 25 g/pig per d from day 2. There was a marked diurnal pattern in heat production, the lowest values being recorded between 24.00 and 08.00 h.3. The mean thermal conductance (H/ΔT, kJ/h per m2 per °ΔT, where His total heat production, m2 is the surface area calculated as 0.097 W kg0.633 (Brody, 1945) and °ΔTis the difference between rectal temperature, taken as 39°, and air temperature) below Tcl was calculated as 18.0, 16.9, 18.5 and 21.2 respectively at 10, 17, 24 and 31 d of age. Maximum values of H/ΔT obtained during feeding periods were. on average, 4.5 kJ/h per me per °ΔT higher than the mean values.4. The maximum value for Tcl during the immediate post-weaning period was 25.9°. The mean Tcl at 17, 24 and 31 d were respectively 21.7, 18.4 and 18.6° for pigs fed almost to appetite.

Exercise and postexercise energy expenditure in growing pigs

1988 ◽  
Vol 66 (6) ◽  
pp. 721-730 ◽  
Author(s):  
Mary Pat Petley ◽  
Henry S. Bayley
Keyword(s):  
Gas Exchange ◽  
Energy Expenditure ◽  
Heat Production ◽  
Open Circuit ◽  
Growing Pigs ◽  
Training Period ◽  
Young Pigs ◽  
Extra Energy ◽  
Energy Dissipated ◽  
And Control

Young pigs (ca. 10 kg) were trained to run on a motor-driven treadmill for 1 h each day. After a 2-week training period the gas exchange of exercised and control animals was measured using an open circuit, indirect calorimeter. The exercised pigs ran for 2 h in the calorimeter, and then rested for 2 h. They received a day's allocation of feed and remained in the calorimeter for a total of 23 h. The total heat production of the exercised pigs was 523 kJ/kg, compared with 433 kJ/kg of the controls. Monitoring the heat production throughout the 23-h period showed that only 43% of the extra heat dissipated by the exercised pigs was lost during the 2 h of exercise, with a higher rate of heat production for the remaining 21 h accounting for the 57% of the extra energy dissipated as heat. The results suggest that exercise increases energy expenditure well beyond the time devoted to the activity itself.

scholarly journals Parameter Identification and State-of-Charge Estimation for Lithium-Ion Batteries Using Separated Time Scales and Extended Kalman Filter

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1054
Author(s):  
Kuo Yang ◽  
Yugui Tang ◽  
Zhen Zhang
Keyword(s):  
Kalman Filter ◽  
Parameter Identification ◽  
Open Circuit Voltage ◽  
Lithium Ion ◽  
Open Circuit ◽  
State Of Charge ◽  
Recursive Least Squares ◽  
Model Parameters ◽  
Soc Estimation ◽  
Battery Model

With the development of new energy vehicle technology, battery management systems used to monitor the state of the battery have been widely researched. The accuracy of the battery status assessment to a great extent depends on the accuracy of the battery model parameters. This paper proposes an improved method for parameter identification and state-of-charge (SOC) estimation for lithium-ion batteries. Using a two-order equivalent circuit model, the battery model is divided into two parts based on fast dynamics and slow dynamics. The recursive least squares method is used to identify parameters of the battery, and then the SOC and the open-circuit voltage of the model is estimated with the extended Kalman filter. The two-module voltages are calculated using estimated open circuit voltage and initial parameters, and model parameters are constantly updated during iteration. The proposed method can be used to estimate the parameters and the SOC in real time, which does not need to know the state of SOC and the value of open circuit voltage in advance. The method is tested using data from dynamic stress tests, the root means squared error of the accuracy of the prediction model is about 0.01 V, and the average SOC estimation error is 0.0139. Results indicate that the method has higher accuracy in offline parameter identification and online state estimation than traditional recursive least squares methods.

GASEOUS METABOLISM IN PREMATURE INFANTS AT 32-34°C AMBIENT TEMPERATURE

PEDIATRICS ◽  
1964 ◽  
Vol 33 (1) ◽  
pp. 75-82
Author(s):  
Forrest H. Adams ◽  
Tetsuro Fujiwara ◽  
Robert Spears ◽  
Joan Hodgman
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Premature Infants ◽  
Rectal Temperature ◽  
Respiratory Quotient ◽  
Carbon Dioxide Production ◽  
Open Circuit ◽  
Co2 Production ◽  
O2 Consumption ◽  
Rate Of Increase

Thirty-four measurements of oxygen consumption, carbon dioxide production, respiratory quotient, and rectal temperature were made on 22 premature infants with ages ranging from 2½ hours to 18 days. The studies were conducted at 32-34°C utilizing an open circuit apparatus and a specially designed climatized chamber. Oxygen consumption and carbon dioxide production were lowest in the first 12 hours and increased thereafter. The rate of increase in O2 consumption was greater than that of CO2 production, with a consequent fall in respiratory quotient during the first 76 hours of life. A reverse relation of O2 consumption and CO2 production was found following the 4th day of life with a consequent rise in respiratory quotient. There was a close correlation between O2 consumption and rectal temperature regardless of age. A respiratory quotient below the value of 0.707 for fat metabolism was observed in 7 premature infants with ages ranging from 24 to 76 hours.

Measurement of ‘Basal’ and Total Metabolism in Hereditarily Obese-Hyperglycemic Mice

1958 ◽  
Vol 193 (3) ◽  
pp. 495-498 ◽  
Author(s):  
Ruth McClintock ◽  
Nathan Lifson
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Energy Expenditure ◽  
Voluntary Movement ◽  
Carbon Dioxide Production ◽  
Open Circuit ◽  
Energy Output ◽  
Obese Mice ◽  
Energy Expenditures ◽  
Isotope Method

Measurements of oxygen consumption and carbon dioxide production were made by the Haldane open circuit method on hereditarily obese mice and littermate controls, and the energy expenditures were estimated. Studies were made on mice for short periods under ‘basal’ conditions, and for periods of approximately a day with the mice fasted and confined, fasted and relatively unconfined, and fed and unconfined. The total energy expenditures of fed and unconfined obese mice were found to be higher than those of nonobese littermate controls by virtue of a) increased ‘basal metabolism’, b) greater energy expenditure associated with feeding, and possibly c) larger energy output for activity despite reduced voluntary movement. The values obtained for total metabolism confirm those previously determined by an isotope method for measuring CO2 output.

Assessment of digestible lysine requirements in lipopolysaccharide-challenged pigs

2021 ◽  
Author(s):  
Joyce Barcellos ◽  
Warley Júnior Alves ◽  
Pedro Riguetti Arnaut ◽  
Lucimauro Fonseca ◽  
Jorge Cunha Lima Muniz ◽  
...  
Keyword(s):  
Rectal Temperature ◽  
Feed Intake ◽  
Total Protein ◽  
Sampling Period ◽  
Experimental Period ◽  
N Deposition ◽  
Growing Pigs ◽  
N Balance ◽  
Model Parameters ◽  
Lps Challenge

Abstract To evaluate the effect of an E. coli lipopolysaccharide (LPS) challenge on the digestible lysine (Lys) requirement for growing pigs, a nitrogen (N) balance assay was performed. Seventy-two castrated male pigs [19 ± 1.49 kg body weight (BW)] were allocated in a 2 x 6 factorial design composed of two immune activation states (control and LPS-challenged) and 6 dietary treatments with N levels of 0.94, 1.69, 2.09, 3.04, 3.23 and 3.97% N, as fed, where Lys was limiting, with six replicates and one pig per unit. The challenge consisted of an initial LPS dose of 30 μg/kg BW via intramuscular (IM) injection and a subsequent dose of 33.6 μg/kg BW after 48 h. The experimental period lasted 11 days and was composed of a 7-day adaptation and a subsequent 4-day sampling period in which N intake (NI), N excretion (NEX) and N deposition (ND) were evaluated. Inflammatory mediators and rectal temperature were assessed during the 4-day collection period. A 3-way interaction (N levels × LPS challenge × time, P < 0.05) for IgG was observed. Additionally, 2-way interactions (challenge × time, P < 0.05) were verified for IgA, ceruloplasmin, transferrin, haptoglobin, α-1-acid glycoprotein, total protein, and rectal temperature; and (N levels × time, P < 0.05) for transferrin, albumin, haptoglobin, total protein and rectal temperature. LPS-challenged pigs showed lower (P < 0.05) feed intake. A 2-way interaction (N levels × LPS challenge, P < 0.05) was observed for NI, NEX and ND, with a clear dose-response (P < 0.05). LPS-challenged pigs showed lower NI and ND at 2.09% N and 1.69 to 3.97% N (P < 0.05), respectively, and higher NEX at 3.23% N (P < 0.05). The parameters obtained by a nonlinear model (N maintenance requirement, NMR and theoretical maximum N deposition, NDmaxT) were 152.9 and 197.1 mg/BWkg  0.75/d for NMR, and 3,524.7 and 2,077.8 mg/BWkg  0.75/d for NDmaxT, for control and LPS-challenged pigs, respectively. The estimated digestible Lys requirements were 1,994.83 and 949.16 mg/BWkg  0.75/d for control and LPS-challenged pigs, respectively. The daily digestible Lys intakes required to achieve 0.68 and 0.54 times the NRmaxT value were 18.12 and 8.62 g/d, respectively, and the optimal dietary digestible Lys concentration may change depending on the feed intake levels. Based on the derived model parameters obtained in the N balance trial with lower cost and time, it was possible to differentiate the digestible Lys requirement for swine under challenging conditions.

Energy content of intact and heat-treated dry extruded-expelled soybean meal fed to growing pigs

2021 ◽  
Author(s):  
Bonjin Koo ◽  
Olumide Adeshakin ◽  
Charles Martin Nyachoti
Keyword(s):  
Heat Production ◽  
Soybean Meal ◽  
Energy Content ◽  
Basal Diet ◽  
Growing Pigs ◽  
Metabolizable Energy ◽  
Energy Utilization ◽  
Experimental Unit ◽  
Net Energy ◽  
Heat Treated

Abstract An experiment was performed to evaluate the energy content of extruded-expelled soybean meal (EESBM) and the effects of heat treatment on energy utilization in growing pigs. Eighteen growing barrows (18.03 ± 0.61 kg initial body weight) were individually housed in metabolism crates and randomly allotted to one of three dietary treatments (six replicates/treatment). The three experimental diets were: a corn-soybean meal-based basal diet and two test diets with simple substitution of a basal diet with intact EESBM or heat-treated EESBM (heat-EESBM) at a 7:3 ratio. Intact EESBM was autoclaved at 121°C for 60 min to make heat-treated EESBM. Pigs were fed the experimental diets for 16 d, including 10 d for adaptation and 6 d for total collection of feces and urine. Pigs were then moved into indirect calorimetry chambers to determine 24-h heat production and 12-h fasting heat production. The energy content of EESBM was calculated using the difference method. Data were analyzed using the Mixed procedure of SAS with the individual pig as the experimental unit. Pigs fed heat-EESBM diets showed lower (P < 0.05) apparent total tract digestibility of dry matter (DM), gross energy, and nitrogen than those fed intact EESBM. A trend (P ≤ 0.10) was observed for greater heat increments in pigs fed intact EESBM than those fed heat-EESBM. This resulted in intact EESBM having greater (P < 0.05) digestible energy (DE) and metabolizable energy (ME) contents than heat-EESBM. However, no difference was observed in net energy (NE) contents between intact EESBM and heat-EESBM, showing a tendency (P ≤ 0.10) toward an increase in NE/ME efficiency in heat-EESBM, but comparable NE contents between intact and heat-EESBM. In conclusion, respective values of DE, ME, and NE are 4,591 kcal/kg, 4,099 kcal/kg, and 3,189 kcal/kg in intact EESBM on a DM basis. It is recommended to use NE values of feedstuffs that are exposed to heat for accurate diet formulation.

Mechanisms of thermal stability during flight in the honeybee apis mellifera

1999 ◽  
Vol 202 (11) ◽  
pp. 1523-1533 ◽  
Author(s):  
S.P. Roberts ◽  
J.F. Harrison
Keyword(s):  
Thermal Stability ◽  
Heat Loss ◽  
Heat Production ◽  
Radiative Heat ◽  
Carbon Dioxide Production ◽  
Metabolic Heat Production ◽  
Evaporative Heat Loss ◽  
Radiative Heat Loss ◽  
Convective Heat Loss ◽  
Metabolic Heat

Thermoregulation of the thorax allows honeybees (Apis mellifera) to maintain the flight muscle temperatures necessary to meet the power requirements for flight and to remain active outside the hive across a wide range of air temperatures (Ta). To determine the heat-exchange pathways through which flying honeybees achieve thermal stability, we measured body temperatures and rates of carbon dioxide production and water vapor loss between Ta values of 21 and 45 degrees C for honeybees flying in a respirometry chamber. Body temperatures were not significantly affected by continuous flight duration in the respirometer, indicating that flying bees were at thermal equilibrium. Thorax temperatures (Tth) during flight were relatively stable, with a slope of Tth on Ta of 0.39. Metabolic heat production, calculated from rates of carbon dioxide production, decreased linearly by 43 % as Ta rose from 21 to 45 degrees C. Evaporative heat loss increased nonlinearly by over sevenfold, with evaporation rising rapidly at Ta values above 33 degrees C. At Ta values above 43 degrees C, head temperature dropped below Ta by approximately 1–2 degrees C, indicating that substantial evaporation from the head was occurring at very high Ta values. The water flux of flying honeybees was positive at Ta values below 31 degrees C, but increasingly negative at higher Ta values. At all Ta values, flying honeybees experienced a net radiative heat loss. Since the honeybees were in thermal equilibrium, convective heat loss was calculated as the amount of heat necessary to balance metabolic heat gain against evaporative and radiative heat loss. Convective heat loss decreased strongly as Ta rose because of the decrease in the elevation of body temperature above Ta rather than the variation in the convection coefficient. In conclusion, variation in metabolic heat production is the dominant mechanism of maintaining thermal stability during flight between Ta values of 21 and 33 degrees C, but variations in metabolic heat production and evaporative heat loss are equally important to the prevention of overheating during flight at Ta values between 33 and 45 degrees C.

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