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 Effects of Feed Intake and Behavior on the Relationship between Heart Rate and Heat Production, and the Evaluation of Energy Balance in Holstein Heifers

1993 ◽  
Vol 64 (4) ◽  
pp. 403-410 ◽  
Author(s):  
Takaaki MATSUMOTO ◽  
B. P. PURWANTO ◽  
Fumio NAKAMASU ◽  
Toshio ITO ◽  
Sadaki YAMAMOTO
Keyword(s):  
Heart Rate ◽  
Energy Balance ◽  
Heat Production ◽  
Feed Intake ◽  
And Behavior ◽  
The Relationship

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.

scholarly journals Effect of high temperature on feeding behaviour and heat production in group-housed young pigs

2001 ◽  
Vol 86 (1) ◽  
pp. 63-70 ◽  
Author(s):  
Anne Collin ◽  
Jacob van Milgen ◽  
Serge Dubois ◽  
Jean Noblet
Keyword(s):  
Physical Activity ◽  
Heat Stress ◽  
Heat Production ◽  
Feed Intake ◽  
Feeding Behaviour ◽  
Voluntary Feed Intake ◽  
Young Pigs ◽  
Body Weights ◽  
Ad Libitum ◽  
Thermic Effect

To assess the acclimation of pigs to heat stress, the effects of high (33°C) or thermoneutral (23°C) constant temperatures on feeding behaviour and components of energy balance were studied in group-housed young pigs. Three groups of five pigs were used at each temperature. After 1 week of adaptation, voluntary feed intake (VFI) and heat production (HP) were recorded for thirteen consecutive days. Animals were fed ad libitum. Fasting HP was measured on the last day. Average initial body weights (BW) were 21·4 and 20·9 kg at 23 and 33°C respectively. Feeding behaviour was measured individually and rate of feed intake and characteristics of feeding behaviour were calculated. The O2 consumption, CO2 production and physical activity of the group were used to calculate total HP (HPtot) and its components, i.e. fasting HP (HPfas), HP due to physical activity (HPact) and thermic effect of feed (TEF). The BW gain and VFI were reduced by 37 and 30 % respectively at 33°C. The decrease in VFI corresponded to reduced consumption time (-34 %) and size of the meals (-32 %). Feeding behaviour was mostly diurnal (66 % of the VFI), and the rate of feed intake (28 g/min) was not affected by temperature. Daily HPtot, HPfas and TEF, expressed per kg metabolic weight (BW0·60), were significantly decreased at 33°C by 22, 18 and 35 % respectively, whereas HPact was not affected; TEF expressed per g feed was not affected (2 kJ/g). The decrease in HPtot at 33°C was caused by a reduction in TEF and HPfas (kJ/d per/kg BW0·60), which are both related to reduction in VFI.

Nychthemeral and seasonal patterns of thermoregulation in cattle

1968 ◽  
Vol 19 (1) ◽  
pp. 181 ◽  
Author(s):  
A Berman
Keyword(s):  
Heat Production ◽  
Feed Intake ◽  
Seasonal Changes ◽  
Late Summer ◽  
Rate Of Change ◽  
Feeding Groups ◽  
Group A ◽  
The Mean ◽  
Group 5 ◽  
The Relationship

1. The nychthemeral (24 hr) and seasonal cycles in thermoregulation at high (Fh) and standard (Fs) levels of feeding were studied in Holstein heifers during spring (mean daily air temperature 18.2°C) and late summer (mean daily air temp. 27.5°). 2. In the two seasons the percentage respiratory evaporative cooling (% RC) and rectal temperature (Tr) displayed marked nychthemeral cycles in both feeding groups, while heat production (Hp) cycles were evident in the Fh group only. 3. In both seasons the effect of the 22.4% larger Hp in the Fhgroup was to prolong the duration of higher % RC; Tr was relatively increased in the summer only. 4. The seasonal changes were: a 20% reduction in Hp in both groups; a larger amplitude of Hp cycling (19% of the mean in summer and 12.9% in spring) in the Fh group; a higher Tr (+ 0.40°C in the Fs group and + 0.63° in the Fh group), cycling with a larger amplitude (0.33° v. 0.52°); a 21° depression in feed intake in the Fh group and 9° in the Fs group. 5. Within each season Tr and the rate of change in Tr were significantly correlated with Hp in the Fh group only. On a between-season basis Hp and Tr were significantly correlated in both feeding groups. These suggest that the relationship between body temperature and heat production follows different patterns in nychthemeral cycles from those in seasonal changes. 6. The nychthemeral patterns of respiratory, %RC, Tr, and Hp responses indicated that the animals were acclimatized to the seasonal change in Tr, possible through a shift in the set-point for temperature control. The depression in heat production and feed intake did not prevent the maintenance of a normal rate of growth.

scholarly journals Examination of energy utilization in cattle offered a forage diet at near- and sub-maintenance levels of feeding

1993 ◽  
Vol 70 (2) ◽  
pp. 381-392 ◽  
Author(s):  
S. B. Cammell ◽  
M. J. Haines ◽  
M. Gill ◽  
M. S. Dhanoa ◽  
J. Frances ◽  
...  
Keyword(s):  
Heat Production ◽  
Linear Models ◽  
Live Weight ◽  
Open Circuit ◽  
Metabolizable Energy ◽  
Energy Utilization ◽  
Mean Values ◽  
Group 2 ◽  
The Relationship ◽  
Group 1

Eight Friesian calves were reared from birth to the start of the experiment at a predetermined growth rate of 1.0 kg/d. Four calves (group 1) commenced the experiment at 22 weeks of age and the remainder (group 2) at 34 weeks, and feed intake was calculated to provide sufficient metabolizable energy to sustain zero energy balance (Em). Between experimental days 30 and 56 at maintenance levels of feeding, respiratory exchange measurements were made using open-circuit calorimetry to provide indirect estimates of heat production (H) simultaneous with measurements of faecal and urinary excretion of energy and N. A datum point for Em and H was established for each animal giving mean values for Em of 491 and 537 and for H of 476 and 511 kJ/kg live weight (LW)0.75 per d for groups 1 and 2 respectively. Treatment levels calculated as 0·25, 0·5, 0·75 and 1·25 of dry matter intake required to sustain the measured Em, were imposed on individual animals after day 56 and further measurements of H and faecal/ urinary balance were made between days 72 and 84 followed by measurements of fasting heat production (FHP) during days 86–90 from the two animals in each group which had received the 0.75 and 1.25 levels of intake. Regression analysis of the treatment levels indicated separate linear models which predicted Em at 419 and 473 kJ/kg LW0·75 per d for groups 1 and 2 respectively. The incorporation of FHP with partitioning of faecal and urinary energy losses measured during fasting altered the relationship but not the predicted Em. Overall predicted Em (days 72–84) from all models were 406 and 478 kJ/kg LW0.75 per d for groups 1 and 2 respectively which were significantly lower (P < 0·05) than Em measured during days 30–56.

Brown fat thermogenesis and cardiac rate regulation during cold challenge in infant rats

1997 ◽  
Vol 272 (4) ◽  
pp. R1308-R1313 ◽  
Author(s):  
M. S. Blumberg ◽  
G. Sokoloff ◽  
R. F. Kirby
Keyword(s):  
Heat Production ◽  
Cardiac Rate ◽  
Rat Pups ◽  
Infant Rats ◽  
Air Temperatures ◽  
Brown Adipose ◽  
Cold Challenge ◽  
Extreme Cold ◽  
Relationship Of ◽  
The Relationship

Infants rats depend on heat production by brown adipose tissue (BAT) during cold challenge. Although it has been suggested that BAT thermogenesis protects the heart in the cold, the relationship of BAT activation to cardiac rate has not been examined directly. In the first experiment, the cardiac rate of 2- and 7- to 8-day-old rat pups was monitored during moderate and extreme cold challenge. Pups at both ages maintained cardiac rate during moderate cold challenge while BAT thermogenesis was increasing. In contrast, cooling to air temperatures at which BAT thermogenesis could increase no further resulted in pronounced bradycardia. In the second experiment, ganglionic blockade was used to eliminate BAT heat production and autonomic control of the heart in 7- to 8-day olds. Blockade suppressed BAT thermogenesis in the cold and led to pronounced decreases in interscapular temperature and cardiac rate. These data suggest that cardiac rate in infant rats is modulated both by the autonomic nervous system and BAT thermogenesis.

Effect of monensin on methane and heat productions of steers fed lucerne hay either ad libitum or at the rate of 250 g/hour

1992 ◽  
Vol 43 (8) ◽  
pp. 1789 ◽  
Author(s):  
JC O'Kelly ◽  
WG Spiers
Keyword(s):  
Heat Production ◽  
Feed Intake ◽  
Methane Production ◽  
Specific Effect ◽  
Rumen Fermentation ◽  
Feeding Regime ◽  
Anorectic Effect ◽  
Feeding Regimes ◽  
Ad Libitum ◽  
Brahman Steers

The effect of monensin supplement (33 mg/kg feed) on methane and heat productions was studied in Brahman steers offered lucerne hay in two feeding regimes: ad libitum (AL) or at the rate of 250 g/h (GPH). The monensin treated animals consumed 65 kg less feed than untreated animals in achieving a mean liveweight gain of.56 kg over 54 days of feeding AL. The 10.5% reduction in daily feed intake due to monensin was associated with a 25.6% reduction in methane production. At equalized feed intakes (adjustments made by covariance) approximately 55% of the reduction in methane caused by monensin was explained by its anorectic effect and 45% by its specific effect on rumen fermentation. In contrast, monensin slightly increased (P = 0.07) liveweight gain, but did not affect methane production in steers fed GPH. Heat production was not significantly altered by the use of monensin in either feeding regime.

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.

HEAT PRODUCTION OF SKIP-A-DAY AND DAILY FED BROILER BREEDER PULLETS

1990 ◽  
Vol 70 (2) ◽  
pp. 667-671 ◽  
Author(s):  
C. D. BENNETT ◽  
S. LEESON ◽  
H. S. BAYLEY
Keyword(s):  
Nutrient Availability ◽  
Heat Production ◽  
Feed Intake ◽  
Open Circuit ◽  
Feed Restriction ◽  
Lower Body ◽  
Diurnal Pattern ◽  
Broiler Breeder ◽  
Body Weights ◽  
Feeding Regimen

Four broiler breeder pullets were reared on a skip-a-day feeding regimen according to breeder recommendations; another four pullets were fed daily the same average feed intake as the skip-a-day fed birds. At 15–17 wk of age the average and diurnal pattern of heat production and respiration quotients were determined using an open-circuit respiration calorimeter. Lower body weights of the skip-a-day fed birds may have been due to the day-to-day fluctuation in nutrient availability. Skip-a-day fed birds produced more heat per kilogram body mass. The diurnal pattern of heat production and respiration quotients indicated that skip-a-day fed birds were absorbing nutrients on the feed-day but were fasting for most of the off-feed day. Key words: Broiler breeder, feed restriction, heat production

scholarly journals A ΔSOC-based equalization strategy applied to industry

2020 ◽  
Author(s):  
Maonan Wang ◽  
Chun Chang ◽  
Feng Ji
Keyword(s):  
Open Circuit ◽  
Battery Pack ◽  
Battery Management System ◽  
Battery Management ◽  
Battery Cell ◽  
New Strategy ◽  
The Difference ◽  
Relative Errors ◽  
The Relationship ◽  
Battery Cells

Abstract The voltage-based equalization strategy is widely used in the industry because the voltage (U) of the battery cell is very easy to obtain, but it is difficult to provide an accurate parameter for the battery management system (BMS). This study proposes a new equalization strategy, which is based on the difference between the state of charge (SOC) of any two battery cells in the battery pack, that is, a ΔSOC-based equalization strategy. The new strategy is not only as simple as the voltage-based equalization strategy, but it can also provide an accurate parameter for the BMS. Simply put, using the relationship between the open circuit voltage and the SOC of the battery pack, the proposed strategy can convert the difference between the voltage of the battery cells into ΔSOC, which renders a good performance. Additionally, the required parameters are all from the BMS, and no additional calculation is required, which makes the strategy as simple as the voltage-based balancing strategy. The four experiments show that the relative errors of ΔSOC estimated by the ΔSOC-based equalization strategy are 0.37%, 0.39%, 0.1% and 0.17%, and thereby demonstrate that the ΔSOC-based equalization strategy proposed in this study shows promise in replacing the voltage-based equalization strategy within the industry to obtain better performance.

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