Energetic response to repeated restraint stress in rapidly growing mice

2000 ◽  
Vol 279 (1) ◽  
pp. E33-E43 ◽  
Author(s):  
Kevin D. Laugero ◽  
Gary P. Moberg

There is a cost of stress that may result in the loss of normal biological function (e.g., growth). Repeated, and even single, applications of stressors have been shown to induce negative energy balance in rodents. However, here we addressed whether this energetic response changes during multiple stress exposure and whether there is complete recovery subsequent to the cessation of stress exposure. These questions were addressed in growing C57Bl/6 mice (31 day) by determining at different times the energetic and endocrine responses after the exposure to restraint (R) stress for 4 h applied once (R1), repeatedly over 3 days (R3), or repeatedly over 7 days (R7). Compared with control values, R elevated ( P < 0.05) plasma corticosterone and reduced plasma insulin-like growth factor I on all days of exposure to the stressor. Seven days, but not 1 or 3 days of R, decreased the net growth (126%, P < 0.05) and deposition of fat (71%, P < 0.05) and lean (60%, P < 0.05) energy over the 7 days. Only R7 depressed the 7-day metabolizable energy intake ( P < 0.05), and R7, but not R1 or R3, increased the overall energy expenditure (10%, P < 0.05). Our results demonstrate that repeated episodes of stress are energetically costly to the rapidly growing animal, but compensatory mechanisms mitigate this cost of repeated stress exposure and permit complete recovery of energy balance after the cessation of stress application.

1984 ◽  
Vol 64 (4) ◽  
pp. 825-832 ◽  
Author(s):  
M. A. McNIVEN

The effect of body fatness on glucose metabolism was studied in six adult crossbred wethers divided into two groups weighing 90 kg (fat) or 55 kg (thin). Glucose turnover measurements were made using 6-3H-glucose by single injection at four levels of metabolizable energy intake: high, 17 MJ/day; intermediate, 10 MJ/day; low, 6 MJ/day; and fasting for both thin and fat groups. The greatest group differences occurred at the high feeding level. Body pool size and glucose space were significantly lower (P < 0.001) for the fat sheep and were reduced at fasting for both fatness levels. The mean irreversible loss rate was not affected by body fatness but was significantly affected (P < 0.001) by feeding level. Glucose recycled as a proportion of total entry rate was significantly affected by body fatness and was dependent on a positive or negative energy balance. When in negative energy balance the sheep maintained blood glucose within the normal range by recycling up to four times more glucose than was utilized. It appears that rate of glucose synthesis is related to energy balance and metabolizable energy intake. A tendency toward insulin insensitivity in the fat sheep could be related to high levels of recycling, and a greater glucose drain or prolonged fast could be more serious with the decreased glucose pool size and space. Key words: Glucose metabolism, ruminant, obese, energy balance


1989 ◽  
Vol 67 (9) ◽  
pp. 994-998 ◽  
Author(s):  
Peter J. H. Jones

The comparative effects of feeding diets containing corn, olive, coconut, or menhaden fish oil on efficiency of energy deposition and on short term energy expenditure were examined in growing hamsters. Diets comprising oils mixed with laboratory diets at 10% oil w/w were fed ad libitum for 3 weeks. Animals fed laboratory diets were used as controls. Body composition was determined before and after the feeding period using 3H2O distribution space. Oxygen consumption was measured in each animal during the final week. Weight gains of groups fed corn and olive oil diets exceeded those of the group fed laboratory diet alone (p < 0.05), although metabolizable energy intakes were similar across groups. Corn oil fed animals demonstrated higher carcass energy gains as fat compared with laboratory diet fed or menhaden oil fed groups. This was reflected in an increased fractional deposition of metabolizable energy intake in the group fed corn oil diet compared with the latter two groups. Fecal energy losses were lower in the group fed corn oil diet, and higher in the group fed laboratory diet alone, compared with other groups. Oxygen consumption did not differ between groups. These findings indicate that feeding dietary fish oil, compared with corn oil, favours energy substrate oxidation reducing the fraction of metabolizable energy partitioned for storage.Key words: energy balance, energy expenditure, dietary fatty acids, hamster.


2012 ◽  
Vol 303 (6) ◽  
pp. R571-R579 ◽  
Author(s):  
Mads Rosenkilde ◽  
Pernille Auerbach ◽  
Michala Holm Reichkendler ◽  
Thorkil Ploug ◽  
Bente Merete Stallknecht ◽  
...  

The amount of weight loss induced by exercise is often disappointing. A diet-induced negative energy balance triggers compensatory mechanisms, e.g., lower metabolic rate and increased appetite. However, knowledge about potential compensatory mechanisms triggered by increased aerobic exercise is limited. A randomized controlled trial was performed in healthy, sedentary, moderately overweight young men to examine the effects of increasing doses of aerobic exercise on body composition, accumulated energy balance, and the degree of compensation. Eighteen participants were randomized to a continuous sedentary control group, 21 to a moderate-exercise (MOD; 300 kcal/day), and 22 to a high-exercise (HIGH; 600 kcal/day) group for 13 wk, corresponding to ∼30 and 60 min of daily aerobic exercise, respectively. Body weight (MOD: −3.6 kg, P < 0.001; HIGH: −2.7 kg, P = 0.01) and fat mass (MOD: −4.0 kg, P < 0.001 and HIGH: −3.8 kg, P < 0.001) decreased similarly in both exercise groups. Although the exercise-induced energy expenditure in HIGH was twice that of MOD, the resulting accumulated energy balance, calculated from changes in body composition, was not different (MOD: −39.6 Mcal, HIGH: −34.3 Mcal, not significant). Energy balance was 83% more negative than expected in MOD, while it was 20% less negative than expected in HIGH. No statistically significant changes were found in energy intake or nonexercise physical activity that could explain the different compensatory responses associated with 30 vs. 60 min of daily aerobic exercise. In conclusion, a similar body fat loss was obtained regardless of exercise dose. A moderate dose of exercise induced a markedly greater than expected negative energy balance, while a higher dose induced a small but quantifiable degree of compensation.


1994 ◽  
Vol 74 (1) ◽  
pp. 97-102 ◽  
Author(s):  
Z. Jiang ◽  
R. J. Hudson

Seasonal energy intakes of 6- to 14-mo-old wapiti hinds were determined in energy balance trials under pen and field conditions in winter, spring and summer. Six animals grazed native pastures supplemented with alfalfa hay when pasture availability declined in winter. Another six were penned and fed alfalfa-barley pellets to maximize growth throughout the year. Season and diet-specific metabolizable energy requirements for maintenance and liveweight gain were determined from regression of metabolizable energy intake on gain. Daily maintenance requirements of penned wapiti ranged from (mean ± SE) 473 ± 35 kJ kg−0.75 in winter to 728 ± 78 kJ kg−0.75 in summer. On spring and summer pasture, daily ecological maintenance requirements ranged from 900 ± 26 to 984 ± 37 kJ kg−0.75. Energy requirements for gain were the same in pen and field trials, ranging from 25 ± 6 to 33 ± 5 kJ g−1 in winter and from 40 ± 6 to 43 ± 12 kJ g−1 in spring and summer. This study provides basic information on the metabolizable energy needs of wapiti and insights into how their seasonal requirements can be optimally met. Key words: Elk, metabolizable energy requirement, growth, physiological maintenance, ecological maintenance, seasonality, energy balance


Endocrinology ◽  
2007 ◽  
Vol 149 (2) ◽  
pp. 544-550 ◽  
Author(s):  
Colin T. Phillips ◽  
Richard D. Palmiter

Hypothalamic neurons that express agouti-related protein (AgRP) and neuropeptide Y (NPY) are thought to be important for regulation of feeding, especially under conditions of negative energy balance. The expression of NPY and AgRP increases during lactation and may promote the hyperphagia that ensues. We explored the role of AgRP neurons in reproduction and lactation, using a mouse model in which AgRP-expressing neurons were selectively ablated by the action of diphtheria toxin. We show that ablation of AgRP neurons in neonatal mice does not interfere with pregnancy, parturition, or lactation, suggesting that early ablation allows compensatory mechanisms to become established. However, ablation of AgRP neurons after lactation commences results in rapid starvation, indicating that both basal feeding and lactation-induced hyperphagia become dependent on AgRP neurons in adulthood. We also show that constitutive inactivation of Npy and Agrp genes does not prevent pregnancy or lactation, nor does it protect lactating dams from diphtheria toxin-induced starvation.


1997 ◽  
Vol 77 (1) ◽  
pp. 99-105 ◽  
Author(s):  
Susanna Iossa ◽  
Maria P. Mollica ◽  
Lillà Lionetti ◽  
Antonio Barletta ◽  
Giovanna Liverini

In the present study energy balance and liver respiratory activity were studied in rats fed on either a control diet or an energy-dense diet. Liver respiration was assessed both without added substrates and after the addition of hexanoate, glycerol, or sorbitol. The effect of ouabain on hexanoate-supported respiration was also determined. Metabolizable energy intake and energy expenditure increased in rats fed on an energy dense diet, but body-weight gain, as well as lipid and protein content, remained unchanged. When net energy expenditure, obtained excluding the total cost of storage, was expressed as a percentage of metabolizable energy, significant differences were found between the two groups of rats. This finding supports the presence of regulatory mechanisms in rats fed on an energy-dense diet, which are useful to counteract development of obesity. In addition, a significant increase in liver respiratory activity was found in rats fed on an energy-dense diet, both in the basal state and in that stimulated by added substrates. Na/K-pump-dependent O2 consumption also increased in rats fed on an energy-dense diet. The results indicate that a greater production of metabolic heat by the liver can contribute to the increased energy expenditure found in rats fed on an energy-dense diet.


1987 ◽  
Vol 44 (3) ◽  
pp. 347-353 ◽  
Author(s):  
P. C. Garnsworthy ◽  
G. P. Jones

ABSTRACTFour groups of 12 cows were fed from between 12 and 18 weeks before calving to achieve condition scores at calving of 2·0 (T) or 3·5 (F). For 20 weeks after calving all cows were offered 10 kg/day of a dairy concentrate (metabolizable energy (ME) 13 MJ/kg dry matter (DM)) containing 74 g undegradable dietary protein (UDP) per kg DM (groups TH and FH) or 45 g/kg DM UDP (groups TL and FL), 2 kg/day sugar-beet pulp, 5 kg/day brewers' grains and hay ad libitum.Milk yields were similar for all groups over the first 20 weeks of lactation, but slightly lower for cows in group FL than for other cows. Cows in group FH lost condition over the first 15 weeks and cows in group FL lost proportionally more condition over the first 12 weeks of lactation. Cows in groups TH and TL increased in condition slightly over the first 20 weeks of lactation. After calving, cows in groups TH and TL had significantly higher intakes of DM, digestible DM and ME than did cows in groups FH and FL (P < 0·001). Cows in group TL had higher intakes than did cows in group TH.Groups TH and FH were in negative energy balance until weeks 10 and 11 respectively. Group FL was in negative energy balance between weeks 4 and 7 and group TL was only in negative energy balance in week 5. The biological efficiency of milk production (energy output in milk/energy intake) was 0·37, 0·35, 0·40 and 0·38 for groups FH, FL, TH and TL respectively.It was concluded that cows which are thin at calving produce more milk directly from food than cows which are fat and are biologically more efficient; higher UDP levels in the diet led to increased negative energy balances but in thin cows this was due to lower food intakes whereas in fat cows this was due to higher milk yields which led to greater losses of condition.


Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 309
Author(s):  
Deise Aline Knob ◽  
André Thaler Neto ◽  
Helen Schweizer ◽  
Anna C. Weigand ◽  
Roberto Kappes ◽  
...  

Crossbreeding in dairy cattle has been used to improve functional traits, milk composition, and efficiency of Holstein herds. The objective of the study was to compare indicators of the metabolic energy balance, nonesterified fatty acids (NEFA), beta-hydroxybutyrate (BHBA), glucose, body condition score (BCS) back fat thickness (BFT), as well as milk yield and milk composition of Holstein and Simmental cows, and their crosses from the prepartum period until the 100th day of lactation at the Livestock Center of the Ludwig Maximilians University (Munich, Germany). In total, 164 cows formed five genetic groups according to their theoretic proportion of Holstein and Simmental genes as follows: Holstein (100% Holstein; n = 9), R1-Hol (51–99% Holstein; n = 30), first generation (F1) crossbreds (50% Holstein, 50% Simmental; n = 17), R1-Sim (1–49% Holstein; n = 81) and Simmental (100% Simmental; n = 27). The study took place between April 2018 and August 2019. BCS, BFT blood parameters, such as BHBA, glucose, and NEFA were recorded weekly. A mixed model analysis with fixed effects breed, week (relative to calving), the interaction of breed and week, parity, calving year, calving season, milking season, and the repeated measure effect of cow was used. BCS increased with the Simmental proportion. All genetic groups lost BCS and BFT after calving. Simmental cows showed lower NEFA values. BHBA and glucose did not differ among genetic groups, but they differed depending on the week relative to calving. Simmental and R1-Sim cows showed a smaller effect than the other genetic groups regarding changes in body weight, BCS, or back fat thickness after a period of a negative energy balance after calving. There was no significant difference for milk yield among genetic groups, although Simmental cows showed a lower milk yield after the third week after calving. Generally, Simmental and R1-Simmental cows seemed to deal better with a negative energy balance after calving than purebred Holstein and the other crossbred lines. Based on a positive heterosis effect of 10.06% for energy corrected milk (ECM), the F1, however, was the most efficient crossbred line.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 158-158
Author(s):  
Phillip A Lancaster

Abstract Multiple linear regression inaccurately computes the efficiency of energy use for protein and fat gain. The objective was to quantify efficiency of metabolizable energy use for protein and fat gain along with heats of product formation and support metabolism. A literature search was performed to compile data (31 studies, 214 treatment means) on metabolizable energy intake (MEI) and composition of empty body gain in growing steers and heifers. Data analyses were performed using R statistical package for mixed models with study as random variable. Linear regression of MEI on energy gain (EG; P &lt; 0.001; R2 = 0.627) resulted in an estimate of metabolizable energy for maintenance (MEm) of 156 kcal/kg.75 and efficiency of ME use for gain of 0.518. Linear regression of MEI on EG as protein and fat (P &lt; 0.001; R2 = 0.623) resulted in an estimate of MEm of 149 kcal/kg.75, and efficiency of protein (kp) and fat (kf) gain of 0.274 and 0.585, respectively, resulting in an overall efficiency of EG of 0.520. Nonlinear regression model (EG = kg*(MEI-MEm)) resulted in an estimate of MEm of 103 kcal/kg.75 and efficiency of EG of 0.342. The heat of product formation was assumed to be 0.48 (1 – 0.52) and the heat of support metabolism (HiEv) 0.18 (0.52 – 0.34). Multivariate regression was used to fit simultaneous models for EG as protein (EGp = (kp+HiEvp)*k*MEA) and fat (EGf = (kf+(0.18-HiEvp))*(1-k)*MEA). Estimates (P &lt; 0.001) of kp and kf were 0.12 ± 0.01 and 0.63 ± 0.02, and HiEvp and proportion of ME available for protein gain (k) were 0.11 ± 0.01 and 0.75 ± 0.01, respectively. The heat of product formation and support metabolism for protein were 0.77 and 0.11, and fat were 0.30 and 0.07, respectively. In conclusion, efficiency of ME use for protein was lesser than for fat gain, and heat of support metabolism was greater for protein than fat gain.


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