scholarly journals Effects of high altitude and season on fasting heat production in the yak Bos grunniens or Poephagus grunniens

2002 ◽  
Vol 88 (2) ◽  
pp. 189-197 ◽  
Author(s):  
Xing-Tai Han ◽  
Ao-Yun Xie ◽  
Xi-Chao Bi ◽  
Shu-Jie Liu ◽  
Ling-Hao Hu

Thirty growing yaks Bos grunniens or Poephagus grunniens, 1·0–3·5 years and 50–230kg, from their native altitudes (3000–4000m), were used to study the basal metabolism in this species and to evaluate the effects of high altitude and season on the energy metabolism. Fasting heat production (FHP) was measured at altitudes of 2260, 3250 and 4270m on the Tibetan plateau in both the summer and the winter, after a 90d adaptation period at each experimental site. Gas exchanges of the whole animals were determined continuously for 3d (4–5 times per d, 10–12 min each time) after a 96 h starvation period, using closed-circuit respiratory masks. Increasing altitude at similar ambient temperature (Ta) did not affect (P>0·10) FHP in the summer, but decreased (P<0·05) it at different Ta in the winter. However, the decrease of FHP in the winter was mainly due to the decrease of Ta instead of the increase of altitude. In the summer, the respiratory rate, heart rate and body temperature were unaffected by altitude, except for a decrease (P<0·05) in body temperature at 4270m; in the winter, they were decreased (P<0·05) by increasing altitude. In both seasons, the RER was decreased (P<0·05) by increasing altitude. At all altitudes for all groups, the daily FHP was higher (P<0·05) in the summer (Ta 6–24°C) than in the winter (Ta 0 to -30°C), and the Ta-corrected FHP averaged on 920 kJ/kg body weight0·52 at Ta 8–14°C and on 704 kJ/kg body weight0·52 at Ta -15°C respectively. We conclude that in the yak high altitude has no effect on the energy metabolism, whereas the cold ambient temperature has a significant depressing effect. The results confirm that the yak has an excellent adaptation to both high altitude and extremely cold environments.

2003 ◽  
Vol 89 (3) ◽  
pp. 399-407 ◽  
Author(s):  
Xing-Tai Han ◽  
Ao-Yun Xie ◽  
Xi-Chao Bi ◽  
Shu-Jie Liu ◽  
Ling-Hao Hu

Growing yellow cattle (Bos taurus, n 30, 1·0–3·5 years old and 75–240 kg) from their native altitude (2000–2800 m) were used to evaluate the effects of altitude, ambient temperature (Ta) and solar radiation on the basal energy metabolism in this large mammal. Fasting heat production (FHP) was measured at altitudes of 2260, 3250 and 4270 m on the Tibetan plateau both in the summer and winter respectively, after a 90 d adaptation period at each experimental site. The gas exchanges of the whole animal were determined continuously for 3 (2260 and 3250 m) or 2 (4270 m) d after a 96 (2260 and 3250 m) or 48 (4270 m) h starvation period, using closed-circuit respiratory masks. Increasing altitude from 2260 to 3250 m at similar Ta in the summer significantly elevated FHP for all animals (P<0·01), and from 3250 to 4270 m for young cattle (P<0·05); increasing altitude from 2260 to 3250 m in the winter also significantly elevated FHP (P<0·05), but the increase was mainly due to the decrease of Ta and the increase in wind speed. No results were obtained at 4270 m in the winter, due to the problems of the animals, adaptating to the altitude. The magnitude of FHP elevation caused by increasing altitude was greater with summer sunshine or winter wind than without them. Increase of Ta from 10·0 to 22·0°C, in the presence of solar radiation, slightly (2260 m) or significantly (3250 and 4270 m, P<0·01) elevated FHP, but slightly reduced it in the absence of solar radiation; decrease of Ta from 0·0 to −30·0°C linearly increased FHP. At 3250 and 4270 m, FHP at the same Ta was higher with summer sunshine or winter wind (3250 m) than without them, but this did not occur at 2260 m. In conclusion, high altitude elevates FHP in yellow cattle in the warm season, and the summer solar radiation and winter wind at high altitude significantly increase metabolic rate. It may be also concluded that the effects of solar radiation on metabolic rate depend on the altitude and the environmental temperature.


2002 ◽  
Vol 88 (2) ◽  
pp. 189-197 ◽  
Author(s):  
Han X-T.* ◽  
A-Y. Xie ◽  
X-C. Bi ◽  
S-J. Liu ◽  
L-H. Hu

1992 ◽  
Vol 55 (3) ◽  
pp. 397-405 ◽  
Author(s):  
J. W. Schrama ◽  
A. Arieli ◽  
M. J. W. Heetkamp ◽  
M. W. A. Verstegen

AbstractSeven groups of five or six Holstein-Friesian male calves were transported to an experimental farm at 2 to 3 days of age. At 6 days of age, heat production (HP) and metabolizable energy (ME) intake were measured for an 8-day period. During this period, calves were exposed to various ambient temperatures: 6, 9, 12 and 15°C. Ambient temperature was constant within days, but changed between days. Calves were fed below (four groups) or near (three groups) the maintenance requirements (290 or 460 kJ ME per kg M0·75 per day).From 6 to 14 days of age the lower critical temperature (Tc) was 12·5°C and HP increased by 8·4 kJ/kg M0·75 per day per °Cfall in ambient temperature below Tc. Both Tc and increase in HP below Tc were not affected by feeding level. Rectal temperature was lower at low ambient temperatures. The decrease in rectal temperature with ambient temperature was greatest at the low feeding level.During the experimental period, calves were not in a steady-state regarding energy metabolism. Heat production decreased with time. This decrease was affected by feeding level and ambient temperature. After arrival, the influence of both ambient temperature and feeding level on the energy metabolism of young calves increased with time.


eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Sangho Yu ◽  
Helia Cheng ◽  
Marie François ◽  
Emily Qualls-Creekmore ◽  
Clara Huesing ◽  
...  

The adipokine leptin acts on the brain to regulate energy balance but specific functions in many brain areas remain poorly understood. Among these, the preoptic area (POA) is well known to regulate core body temperature by controlling brown fat thermogenesis, and we have previously shown that glutamatergic, long-form leptin receptor (Lepr)-expressing neurons in the POA are stimulated by warm ambient temperature and suppress energy expenditure and food intake. Here we further investigate the role of POA leptin signaling in body weight regulation and its relationship to body temperature regulation in mice. We show that POA Lepr signaling modulates energy expenditure in response to internal energy state, and thus contributes to body weight homeostasis. However, POA leptin signaling is not involved in ambient temperature-dependent metabolic adaptations. Our study reveals a novel cell population through which leptin regulates body weight.


2012 ◽  
Vol 11 (13) ◽  
pp. 2333-2341 ◽  
Author(s):  
D.F. Li ◽  
Q. Hu ◽  
F.L. Wang ◽  
X.S. Piao ◽  
J.J. Ni ◽  
...  

1965 ◽  
Vol 20 (3) ◽  
pp. 405-410 ◽  
Author(s):  
Hermann Pohl

Characteristics of cold acclimation in the golden hamster, Mesocricetus auratus, were 1) higher metabolic rate at -30 C, 2) less shivering when related to ambient temperature or oxygen consumption, and 3) higher differences in body temperature between cardiac area and thoracic subcutaneous tissues at all ambient temperatures tested, indicating changes in tissue insulation. Cold-acclimated hamsters also showed a rise in temperature of the cardiac area when ambient temperature was below 15 C. Changes in heat distribution in cold-acclimated hamsters suggest higher blood flow and heat production in the thoracic part of the body in the cold. The thermal conductance through the thoracic and lumbar muscle areas, however, did not change notably with lowering ambient temperature. Marked differences in thermoregulatory response to cold after cold acclimation were found between two species, the golden hamster and the thirteen-lined ground squirrel, showing greater ability to regulate body temperature in the cold in hamsters. hibernator; oxygen consumption— heat production; body temperature — heat conductance; muscular activity — shivering; thermoregulation Submitted on July 6, 1964


1998 ◽  
Vol 79 (6) ◽  
pp. 509-517 ◽  
Author(s):  
J. Van Milgen ◽  
J. F. Bernier ◽  
Y. Lecozler ◽  
S. Dubois ◽  
J. Noblet

A total of sixty-five observations on heat production during fasting and physical activity were obtained in four groups of pigs differing in breed and/or castration (Meishan (MC) and Large White (LWC) castrates and Large White (LWM) and Piétrain (PM) males) with body weight (BW) ranging between 25 and 60 kg. Pigs were fed ad libitum before fasting. Heat production was measured using indirect calorimetry. Fasting heat production (FHP) was proportional to the body weight raised to the power 0.55, but with group-specific proportionality parameters (810, 1200, 1220 and 1120kJ/kg BW0.55 per d for MC, LWC, LWM and PM respectively). Group effects could be removed by expressing FHP as a function of muscle, viscera and fat: FHP (kJ/d) = 457(muscle)0.81 + 1969(viscera)0.81 - 644(fat)0.81. It is hypothesized that different breeds with equal muscle and visceral mass, can have different FHP. The negative coefficient for fat would then be the result of a low FHP rather than a cause of it. Because a large part of the variation in tissue composition between groups was due to MC group, a separate equation for the lean groups was established. For lean pigs, FHP could be expressed as a function of muscle and viscera alone: FHP (kJ/d) = 508(muscle)0.66 + 2011(viscera)0.66. Both type of pig and BW affected the number of bouts of physical activities (i.e. standing or sitting) per day, the duration of activity and the total cost of activity. Energetic cost of activity was proportional to the muscle mass raised to the power 0.91 (FHPactivity (kJ/h activity) = 21.0(muscle)0.91). Physical activity represented less than 10% of the total heat production in fasting growing pigs housed alone in metabolic cages and kept in a quiet environment.


1985 ◽  
Vol 53 (2) ◽  
pp. 301-305 ◽  
Author(s):  
Khub Singh ◽  
N. K. Bhattacharyya

1. Resting heat production, 18 h post-feeding, was studied in Hariana cattle (Bos indicus; Zebu) and in their F1 crosses with Jersey, Brown Swiss and Holstein Friesian, at 18.5° ambient temperature in a psychrometric chamber at different ages.2. There was no significant change in the resting heat production on a per kg body-weight (W)0.75 per 24 h basis from 16–19 to 37–40 months of age in any of the genetic groups. The daily resting heat production, however, increased with increases in body-weight and age.3. The resting heat production in all three F1 crosses was higher than that in Hariana cattle. Among the crosses, the resting heat production was highest in the Holstein Friesian x Hariana and lowest in the Jersey x Hariana.4. Metabolizable energy (ME) intake per 24 h was significantly different between genetic groups and in different age groups. However, ME intake per kg W0.75 was not significantly different between genetic groups.


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