scholarly journals On the calculation of heat production from open-circuit calorimetric measurements

1972 ◽  
Vol 27 (3) ◽  
pp. 597-600 ◽  
Author(s):  
J. A. McLean
Keyword(s):  
Oxygen Concentration ◽  
Heat Production ◽  
Methane Production ◽  
Respiratory Quotient ◽  
Ventilation Rate ◽  
Open Circuit ◽  
Calorimetric Measurements ◽  
Ruminant Animals ◽  
New Form

1. The equation used for calculating heat production of ruminant animals is expressed in a new form, convenient for application to open-circuit calorimetry.2. It is shown that in open-circuit calorimetry the possible error involved in making the assumption that respiratory quotient is equal to unity is small compared with the possible error involved in neglecting methane production.3. In open-circuit calorimetry heat production can be predicted with accuracy to within ± 2% solely from the measurement of oxygen concentration and ventilation rate.

The effect of simulated altitude on the heat increment of feed in sheep

1978 ◽  
Vol 39 (3) ◽  
pp. 659-661 ◽  
Author(s):  
K. L. Blaxter
Keyword(s):  
Oxygen Concentration ◽  
Heat Production ◽  
Methane Production ◽  
Energy Losses ◽  
Simulated Altitude ◽  
Heat Increment

1. Sheep given constant feed were exposed to environments in which the oxygen concentration in air was either 200 or 150 ml/l. There were no differences in daily heat production, methane production, urinary energy or faecal energy losses measured over periods of 4 d.2. When the sheep were fasted there were no differences in heat production to be ascribed to the O2 concentration in air. The thermic response to feed was unaffected by the O2 concentration in the air.

The respiratory quotient in indirect calorimetric measurements

1983 ◽  
Vol 24 (2) ◽  
pp. 273-279 ◽  
Author(s):  
F. M. G. Boshouwers ◽  
Elly Nicaise
Keyword(s):  
Respiratory Quotient ◽  
Calorimetric Measurements

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.

scholarly journals Effects of lighting regimen on metabolic rate in broilers.

1992 ◽  
Vol 40 (2) ◽  
pp. 111-121 ◽  
Author(s):  
M.J.W. Heetkamp ◽  
A.M. Henken ◽  
W. van der Hel ◽  
C.W. Scheele
Keyword(s):  
Metabolic Rate ◽  
Heat Production ◽  
Respiratory Quotient ◽  
Feeding Time ◽  
Lighting Regimen

From hatching to 42 days old, 80 broilers were exposed to varying periods of light (L) and dark (D) within 4-h periods (0.5L to 1.5L and 3.5D to 2.5D). Effects of lighting regimen (LR) and trough position (open (F2) compared with closed (F1)) during D-periods on heat production (H), activity-free (Hacf) and activity-related H (Hac), and respiratory quotient (RQ) were evaluated. At 0.5L and 0.67L, Hac was less than in the longer L-periods. The longer the L-period, the less active broilers were at the end of a L-period. In D-periods with F1, H and Hacf decreased more than with F2, while Hac was similar. After D-periods with F1, H and Hacf increased more than after D-periods with F2. This effect on H was greatest in short L-periods with F1. With 0.5L:3.5D and F1, broilers did not have enough feeding time, because at the end of the L-period afterwards, H and RQ were lower than with the longer L-periods. Thus, broilers will eat feed in the dark and the length of L-period may not be crucial, because in practice, feed will remain available in the dark. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Heat Production and Respiratory Quotient Changes with Food Intake in Swine

1977 ◽  
Vol 20 (5) ◽  
pp. 0954-0960 ◽  
Author(s):  
D. P. Stombaugh ◽  
A. P. Grifo ◽  
Jr.
Keyword(s):  
Food Intake ◽  
Heat Production ◽  
Respiratory Quotient

The effect of frequency of feeding milk replacer to pre-ruminant calves on respiratory quotient and the efficiency of food utilization

1986 ◽  
Vol 43 (3) ◽  
pp. 367-375 ◽  
Author(s):  
P. E. V. Williams ◽  
R. J. Fallon ◽  
J. M. Brockway ◽  
G. M. Innes ◽  
A. C. Brewer
Keyword(s):  
Energy Balance ◽  
Respiratory Quotient ◽  
Milk Powder ◽  
Live Weight ◽  
Open Circuit ◽  
Energy Utilization ◽  
Milk Replacer ◽  
Food Utilization ◽  
Once Daily ◽  
The Mean

ABSTRACTThirty-four British Friesian bull calves were used in experiments to identify diurnal patterns of respiratory quotient (RQ), as an indicator of substrate utilization and to measure energy balance when the same daily amount of milk replacer was given on either 1, 2, 4 or 6 occasions. Each calf spent two 4-day periods in an open-circuit respiration chamber followed immediately, in selected calves, by an 8-day period in a metabolism crate, period 1 starting when calves were 12 days of age and period 2 at 28 days of age. The amount of milk replacer given daily was 32 and 48 g/kg M0·75 during periods 1 and 2 respectively.Neither rate of live-weight gain nor the energy balance of the calves was affected by frequency of feeding. However, raising the frequency of feeding from one to four times daily significantly affected the pattern of RQ. Reduced feeding frequency tended to raise the mean maximum and lower the mean minimum values of RQ; reducing the frequency of feeding significantly increased the range in RQ (F < 0·01).The apparent dry-matter digestibility of the milk replacer was higher in 36-day-old than in 20-day-old calves (0·93 v. 0·88; s.e.d. 0·011, P < 0·01). The effect was mainly due to an increase in the digestibility of fat (0·82 v. 0·73; s.e.d. 0·019). In 20-day-old calves, there was a linear increase in fat digestibility with increased frequency of feeding (P < 0·01) rising from 0·67 in calves given milk once daily to 0·85 when milk was given in six meals.The results suggest that calves given milk replacer once daily (at a level of intake of 32 rising to 48 g milk powder per kg M0·75) do not pass through a diurnal period of severe nutrient deprivation and that raising frequency of feeding would do little to improve efficiency of energy utilization.

Sign in / Sign up

Export Citation Format

Share Document