SEASONAL ENERGY EXPENDITURES AND THERMOREGULATORY RESPONSES OF BISON AND CATTLE

1979 ◽  
Vol 59 (3) ◽  
pp. 611-617 ◽  
Author(s):  
R. J. CHRISTOPHERSON ◽  
R. J. HUDSON ◽  
M. K. CHRISTOPHERSEN
Keyword(s):  
Cold Exposure ◽  
Low Temperatures ◽  
Metabolic Rates ◽  
Heart Rates ◽  
Ambient Temperatures ◽  
Energy Expenditures ◽  
Thermoregulatory Responses ◽  
Air Temperatures ◽  
Wind Velocities

The metabolic rates of two bison and four Hereford spring-born calves were measured at monthly intervals from December until the following November. Following adaptation at seasonal ambient temperatures, metabolic measurements were made while calves were exposed to controlled temperatures of +10, 0 and −30 °C. Exposure of the Hereford calves to −30 °C resulted in increased metabolic rates during the first 6 mo of the study but the magnitude of the response was greatly attenuated as the calves grew larger. At −30 °C, bison calves either maintained or reduced metabolic rates compared to expenditures at +10 °C. When the calves were about 17 mo of age, they were exposed to a combination of low temperatures and wind. Wind velocities of 4.7 km∙h−1 did not influence metabolic rates of either bison or Herefords at air temperatures of 0 °C. However, at −30 °C, metabolic rates increased from 650 and 700 KJ∙kg−.75∙d−1 to 835 and 950 KJ∙kg−.75∙d−1 in Hereford and bison calves, respectively. Neither respiratory frequencies nor heart rates were influenced significantly during cold exposure, but heart rates increased in response to wind. In general, metabolic rates and heart rates were lower in bison calves.

Seasonal energy expenditures and thermoregulatory responses of moose

1986 ◽  
Vol 64 (2) ◽  
pp. 322-327 ◽  
Author(s):  
Lyle A. Renecker ◽  
Robert J. Hudson
Keyword(s):  
Body Weight ◽  
Early Summer ◽  
Metabolic Rates ◽  
Ambient Temperatures ◽  
Energy Expenditures ◽  
Respiration Rates ◽  
Thermoregulatory Responses ◽  
Heat Increment Of Feeding ◽  
Heat Increment ◽  
Resistance To Heat

Metabolic rates and thermoregulatory responses were studied in adult moose (Alces alces) exposed to various ambient temperatures during winter and summer. Resting energy expenditures followed a marked annual cycle with a maximum (940 kJ kg body weight−0.75 d−1) during spring – early summer and minimum (430 kJ kg body weight−0.75 d−1) during winter. The heat increment of feeding associated with a pelleted ration was 6–9 kJ kg body weight−0.75 h−1. The energy cost of standing was 4.2 kJ kg body weight−0.75 h−1, an increment of 25% over the lying posture. Although piloerection was observed between −25 and −30 °C, metabolic rates did not increase. In contrast to their cold tolerance, moose were easily heat stressed. During winter, moose increased respiration rates when ambient temperatures rose above −5 °C. Resistance to heat load was greater for standing moose during summer; respiration rate increased above 14 °C and open-mouthed panting began at 20 °C. Energy expenditure and heart rate followed a similar rise with increasing ambient temperature.

CALCULATED DETERMINATION OF PRE-HEATING PARAMETERS FOR WELDING POLYETHYLENE PIPES FOR GAS PIPELINES AT LOW AIR TEMPERATURES.

2021 ◽  
pp. 29-31
Author(s):  
I. Tarabukin
Keyword(s):  
Low Temperatures ◽  
Weld Seam ◽  
Gas Pipelines ◽  
Ambient Temperatures ◽  
Regulatory Documents ◽  
Polyethylene Pipes ◽  
Heated Air ◽  
Air Temperatures ◽  
Different Characteristics

According to regulatory documents, welding can be performed at ambient temperatures from minus 15 ° C to plus 45 ° C. When laying gas pipelines at a lower outside temperature, it is necessary to organize their heating to the required temperature. In this case, the temperature of the heated air should not be more than plus 60 ° C. If you start working with a polyethylene (PE) pipe at low temperatures, then the PE pipe will have completely different characteristics. The weld seam may not be reliable.

Acclimatization of Scottish Blackface sheep to cold. 2. Skin temperature, heart rate, respiration rate, shivering intensity and skinfold thickness

1968 ◽  
Vol 10 (1) ◽  
pp. 17-35 ◽  
Author(s):  
A. R. Sykes ◽  
J. Slee
Keyword(s):  
Heart Rate ◽  
Skin Temperature ◽  
Cold Exposure ◽  
Chronic Exposure ◽  
Physiological Responses ◽  
Skinfold Thickness ◽  
Acute Exposure ◽  
Heart Rates ◽  
Ambient Temperatures ◽  
Acute Cold Exposure

Closely shorn Scottish Blackface female sheep aged 9–14 months, half on high plane and half on low plane nutrition, were subjected, in climate chambers, to two short acute cold exposures down to −20°C. The acute exposures were separated by two weeks chronic exposure to a moderately subcriticai temperature (+8°C) or to a thermoneutral temperature (+30°C). Most of the sheep showed a greater resistance to body cooling at the second acute exposure (Slee and Sykes, 1967). This increased resistance to hypothermia, defined as acclimatization, was apparently influenced more by acute than by chronic cold exposure. The present paper deals with changes in skin temperature, heart rate, shivering intensity and skinfold thickness which also resulted from cold exposure, and accompanied acclimatization.After acute cold exposure followed by chronic exposure to +8°C the following changes in these parameters were observed:1. Extremity skin temperatures and heart rates were consistently increased at thermoneutral ambient temperatures.2. Vasoconstriction of the extremities and increased heart rate, both of which normally occur during the early stages of cold exposure, were delayed.3. Heart rates at sub-zero ambient temperatures were increased.4. Cold-induced vasodilatation at sub-zero ambient temperatures was increased.After acute cold treatment alone the intensity of shivering during the second acute exposure was reduced. Also the onset of foot vasoconstriction was slightly delayed.A highly significant relationship was observed between shivering intensity and heart rate during cold exposure.Plane of nutrition had less effect on the physiological responses to cooling than did previous cold experience.It was suggested in discussion that the physiological responses associated with acclimatization were: elevated basal metabolic rate, delayed onset of vasoconstriction and delayed metabolic response to cold, and consequent lowering of the critical temperature. Summit metabolism was also increased and shivering intensity reduced during acute cold exposure. Some of these responses could have resulted from either acute or chronic moderate cold exposure. However their persistence, once induced, appeared to depend upon continued exposure to moderate cold.

Flower cold hardiness: a potential determinant of the flowering sequence exhibited by bog ericads

1979 ◽  
Vol 57 (9) ◽  
pp. 997-999 ◽  
Author(s):  
R. J. Reader
Keyword(s):  
Low Temperatures ◽  
Cold Hardiness ◽  
Vaccinium Macrocarpon ◽  
Southern Ontario ◽  
Air Temperatures ◽  
Insect Pollinators ◽  
Cold Hardy ◽  
Vaccinium Myrtilloides ◽  
Potential Determinant ◽  
Ledum Groenlandicum

In laboratory freezing trials, cold hardiness of six types of bog ericad flowers differed significantly (i.e., Chamaedaphne calyculata > Andromeda glaucophylla > Kalmia polifolia > Vaccinium myrtilloides > Ledum groenlandicum > Vaccinium macrocarpon) at air temperatures between −4 and −10 °C but not at temperatures above −2 °C. At the Luther Marsh bog in southern Ontario, low temperatures (−3 to −7 °C) would select against May flowering by the least cold hardy ericads. Availability of pollinators, on the other hand, would encourage May flowering by the most cold hardy species. Presumably, competition for insect pollinators has promoted the diversification of bog ericad flowering peaks, while air temperature, in conjunction with flower cold hardiness, determined the order in which flowering peaks were reached.

Ambient temperatures, heatwaves and out-of-hospital cardiac arrest in Brisbane, Australia

2021 ◽  
pp. oemed-2020-107018
Author(s):  
Tan N Doan ◽  
Daniel Wilson ◽  
Stephen Rashford ◽  
Emma Bosley
Keyword(s):  
Cardiac Arrest ◽  
Temperature Distribution ◽  
Low Temperatures ◽  
Meteorological Data ◽  
Reference Temperature ◽  
Ambient Temperatures ◽  
Distributed Lag ◽  
Exposure Response ◽  
Heat Threshold ◽  
Hospital Cardiac Arrest

BackgroundThe health impacts of temperatures are gaining attention in Australia and worldwide. While a number of studies have investigated the association of temperatures with the risk of cardiovascular diseases, few examined out-of-hospital cardiac arrest (OHCA) and none have done so in Australia. This study examined the exposure–response relationship between temperatures, including heatwaves and OHCA in Brisbane, Australia.MethodsA quasi-Poisson regression model coupled with a distributed lag non-linear model was employed, using OHCA and meteorological data between 1 January 2007 and 31 December 2019. Reference temperature was chosen to be the temperature of minimum risk (21.4°C). Heatwaves were defined as daily average temperatures at or above a heat threshold (90th, 95th, 98th, 99th percentile of the yearly temperature distribution) for at least two consecutive days.ResultsThe effect of any temperature above the reference temperature was not statistically significant; whereas low temperatures (below reference temperature) increased OHCA risk. The effect of low temperatures was delayed for 1 day, sustained up to 3 days, peaking at 2 days following exposures. Heatwaves significantly increased OHCA risk across the operational definitions. When a threshold of 95th percentile of yearly temperature distribution was used to define heatwaves, OHCA risk increased 1.25 (95% CI 1.04 to 1.50) times. When the heat threshold for defining heatwaves increased to 99th percentile, the relative risk increased to 1.48 (1.11 to 1.96).ConclusionsLow temperatures and defined heatwaves increase OHCA risk. The findings of this study have important public health implications for mitigating strategies aimed at minimising temperature-related OHCA.

EFFECTS OF LOW FLUCTUATING TEMPERATURES ON FARM ANIMALS.: III. INFLUENCE OF AMBIENT AIR TEMPERATURE ON FEED INTAKE OF LACTATING HOLSTEIN-FRIESIAN COWS

1958 ◽  
Vol 38 (2) ◽  
pp. 148-159 ◽  
Author(s):  
M. A. MacDonald ◽  
J. M. Bell
Keyword(s):  
Milk Production ◽  
Air Temperature ◽  
Low Temperatures ◽  
Ambient Air ◽  
Feed Consumption ◽  
Ambient Temperatures ◽  
Ambient Air Temperature ◽  
Holstein Friesian ◽  
Cent Level ◽  
Friesian Cows

This report presents effects of low temperatures on the feed consumption and efficiency of milk production of six mature, lactating, Holstein-Friesian cows that were confined in stanchions for three fortnightly experimental periods during which ambient temperatures measured in degree-hours per day (d-h/day) ranged from 110 to 1152 and daily minimum ambient air temperature (DMAAT) varied from 0° to 38°F. Applying results obtained, it was calculated that as temperatures decreased, i.e., d-h/day increased from 100 to 1200 and DMAAT decreased from 40° to 0°F, average daily intakes of total dry matter, hay, and gross and digestible Calories increased approximately 6.4 lb., 5.3 lb., 13 Therms and 9 Therms, respectively. Each of these increases was statistically significant at the 1 per cent level. Reductions in temperature also decreased gross and net caloric efficiencies of milk production approximately 10 and 8.5 per cent, respectively. These decreases were significant at the 2 per cent level. No correlation was evident between crude protein utilization and temperature.Results indicated that thermal stress was not overcome adequately by supplementary hay intake alone and that appetite stimulation by low temperatures had a carry-over effect continuing at least 24 hours. For continued efficient milk production during winters where low ambient temperatures are prevalent these results suggest it is necessary to provide some form of building insulation, ambient heat and/or provide a high energy supplement to otherwise adequate production rations.

scholarly journals Performance Evaluation of a CO2 Refrigeration System Enhanced with a Dew Point Cooler

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1079 ◽  
Author(s):  
Martin Belusko ◽  
Raymond Liddle ◽  
Alemu Alemu ◽  
Edward Halawa ◽  
Frank Bruno
Keyword(s):  
Weather Conditions ◽  
Dew Point ◽  
Coefficient Of Performance ◽  
Experimental Program ◽  
Refrigeration System ◽  
Conventional System ◽  
Ambient Temperatures ◽  
Air Temperatures ◽  
Condenser Temperature

Dew point cooling (DPC) is a novel indirect evaporative cooling concept capable of delivering air temperatures approaching the dew point. Coupling this technology with CO2 refrigeration is well suited to minimising transcritical operation when the coefficient of performance (COP) is dramatically reduced in hot climates. A substantial experimental program was conducted to characterise this combination by testing a 20 kW CO2 refrigeration system subject to ambient temperatures above 40 °C. It was demonstrated that DPC operation not only avoided transcritical operation during such weather conditions, but also increased the COP by up to 140% compared to the conventional system. The combination of these technologies was successfully mathematically modelled, from which the optimum condenser inlet air temperature was identified for each condenser temperature. Using this optimum condition, it was possible to maximise the COP for a range of conditions applicable to the psychometric chart. An annual case study for Adelaide, Australia was conducted which demonstrated that optimally coupling DPC with CO2 refrigeration can reduce the annual energy consumption and peak demand by 16% and 47%, respectively, compared to a conventional CO2 booster system. Furthermore, the number of hours of transcritical operation was reduced from 3278 to 27.

Characterization and regulation of cold-induced heat shock protein expression in mouse brown adipose tissue

1995 ◽  
Vol 269 (1) ◽  
pp. R38-R47 ◽  
Author(s):  
J. M. Matz ◽  
M. J. Blake ◽  
H. M. Tatelman ◽  
K. P. Lavoi ◽  
N. J. Holbrook
Keyword(s):  
Adipose Tissue ◽  
Heat Shock ◽  
Brown Adipose Tissue ◽  
Cold Exposure ◽  
Elevated Temperatures ◽  
Uncoupling Protein ◽  
Hsp70 Expression ◽  
Mitochondrial Uncoupling ◽  
Ambient Temperatures ◽  
Brown Adipose

The accumulation of heat shock proteins (HSPs) after the exposure of cells or organisms to elevated temperatures is well established. It is also known that a variety of other environmental and cellular metabolic stressors can induce HSP synthesis. However, few studies have investigated the effect of cold temperature on HSP expression. Here we report that exposure of Institute of Cancer Research (ICR) mice to cold ambient temperatures results in a tissue-selective induction of HSPs in brown adipose tissue (BAT) coincident with the induction of mitochondrial uncoupling protein synthesis. Cold-induced HSP expression is associated with enhanced binding of heat shock transcription factors to DNA, similar to that which occurs after exposure of cells or tissues to heat and other metabolic stresses. Adrenergic receptor antagonists were found to block cold-induced HSP70 expression in BAT, whereas adrenergic agonists induced BAT HSP expression in the absence of cold exposure. These findings suggest that norepinephrine, released in response to cold exposure, induces HSP expression in BAT. Norepinephrine appears to initiate transcription of HSP genes after binding to BAT adrenergic receptors through, as yet, undetermined signal transduction pathways. Thermogenesis results from an increase in activity and synthesis of several metabolic enzymes in BAT of animals exposed to cold challenge. The concomitant increase in HSPs may function to facilitate the translocation and activity of the enzymes involved in this process.

scholarly journals Behavior and Energy Losses of Cows during the Period of Low Temperatures

2021 ◽  
Vol 24 (5) ◽  
pp. 46-53
Author(s):  
Oleksandr O. Borshch ◽  
Oleksandr V. Borshch ◽  
Yurii Mashkin ◽  
Vasyl Malina ◽  
Maxim Fedorchenko
Keyword(s):  
Low Temperatures ◽  
Heat Insulation ◽  
Energy Losses ◽  
Strong Wind ◽  
The Past ◽  
Air Temperatures ◽  
The Difference ◽  
And Behavior ◽  
Positive Effect ◽  
Moderate Climate

Over the past 20 years, dairy farms in Ukraine have been actively introducing the keeping of cows in easy-to-assemble premises. However, in a moderate climate (with four distinct year seasons), the issues of microclimate, energy losses of animals and their behavior during the cold period of the year for keeping in such premises have not been fully studied. The purpose of this work was to study the influence of the heat insulation elements use of side curtains in easy-to-assemble premises during the period of low temperatures on microclimate, energy outgoings for thermoregulation and behavior of cows. The research conducted in the central part of Ukraine (Kyiv region). The research was conducted during January-February (29-43 days of the year) 2021. This period characterized by low average daily temperatures of -12.2– -18.7°С, strong wind gusts and daily precipitation in the form of snow. Two easy-toassemble premises for 400 heads were used for research. Parameters of placements (LxWxH): 150х32х10.5 m. The first one was without the use of curtains heat insulation elements, and the second one was with these elements of heat insulation. It was found that the use of polycarbonate wall heat insulation elements had a positive effect on the microclimate in the placement during the period of low temperatures. Indicators of average daily air temperatures in the placement were 3.2 and 8.8°C higher compared to the temperature in the same premise without the use of heat insulation elements and the environment. The wind speed also differed by 0.18 and 11.04 m/s, respectively. In addition, the heat insulation of the walls affected the temperature under the lying cow (+1.8°C), energy outgoings for thermoregulation (-1.93 MJ) and the number of cows that lay in the period of the lowest temperatures (+3.23-9.83%) compared to the placement without heat insulation elements. The difference in temperature of rubber carpet in the compared premises was significant: +3.3°C in the premises with heat insulation elements compared to the premises without heat insulation

Sign in / Sign up

Export Citation Format

Share Document