scholarly journals Food and temperature change photoperiodic responses in two vole species

2021 ◽  
Author(s):  
Laura van Rosmalen ◽  
Roelof A. Hut
Keyword(s):  
Energy Balance ◽  
Gonadal Development ◽  
Reproductive Organ ◽  
Negative Energy ◽  
Thyroid Stimulating Hormone ◽  
Pars Tuberalis ◽  
Organ Development ◽  
Ambient Temperatures ◽  
Photoperiodic Responses ◽  
Save Energy

Seasonal timing of reproduction in voles is driven by photoperiod. Here we hypothesize that a negative energy balance can modify spring-programmed photoperiodic responses in the hypothalamus, controlling reproductive organ development. We manipulated energy balance by the ‘work-for-food’ protocol, in which voles were exposed to increasing levels of food scarcity at different ambient temperatures under long photoperiod. We reveal that in common voles (Microtus arvalis) and tundra voles (Microtus oeconomus), photoperiodic induced pars tuberalis thyroid-stimulating hormone β-subunit (Tshβ) expression is reduced to potentially inhibit gonadal development when food is scarce. Reduction in gonadal size is more pronounced in tundra voles, in which anterior hypothalamic Kiss1 is additionally downregulated, especially in males. Low temperature additionally leads to decreased hypothalamic Rfrp expression, which potentially may facilitate further suppression of gonadal growth. Shutting off the photoperiodic-axis when food is scarce in spring may be an adaptive response to save energy, leading to delayed reproductive organ development until food resources are sufficient for reproduction, lactation and offspring survival. Defining the mechanisms through which metabolic cues modify photoperiodic responses will be important for a better understanding of how environmental cues impact reproduction.

scholarly journals Food and temperature change photoperiodic responses in two vole species: different roles for hypothalamic genes

2021 ◽  
Author(s):  
Laura van Rosmalen ◽  
Roelof A. Hut
Keyword(s):  
Energy Balance ◽  
Gonadal Development ◽  
Reproductive Organ ◽  
Negative Energy ◽  
Thyroid Stimulating Hormone ◽  
Pars Tuberalis ◽  
Organ Development ◽  
Ambient Temperatures ◽  
Photoperiodic Responses ◽  
Save Energy

AbstractSeasonal timing of reproduction in voles is driven by photoperiod. Here we hypothesize that a negative energy balance can modify spring-programmed photoperiodic responses in the hypothalamus, controlling reproductive organ development. We manipulated energy balance by the ‘work-for-food’ protocol, in which voles were exposed to increasing levels of food scarcity at different ambient temperatures under long photoperiod. We reveal that common (Microtus arvalis) and tundra voles (Microtus oeconomus), reduce photoperiodic induced pars tuberalis thyroid-stimulating hormone β-subunit (Tshβ) expression to inhibit gonadal development when food is scarce. Reduction in gonadal size is more pronounced in tundra voles, in which the hypothalamic Kisspeptin (Kiss1) system seems involved in downregulating gonadal development, especially in males. Low temperature additionally leads to decreased hypothalamic RF-amide related peptide (Rfrp3) levels, which may facilitate further suppression of gonadal growth. Shutting off the photoperiodic-axis when food is scarce in spring may be an adaptive response to save energy, leading to delayed reproductive organ development until food resources are sufficient for reproduction, lactation and offspring survival. Defining the mechanisms through which metabolic cues modify photoperiodic responses will be important for a better understanding of how environmental cues impact reproduction.Summary statementThis study provides a better understanding of the molecular mechanism through which metabolic cues can modify photoperiodic responses, to adaptively adjust timing of reproductive organ development

scholarly journals Negative energy balance and leptin regulate neuromedin-U expression in the rat pars tuberalis

2006 ◽  
Vol 190 (2) ◽  
pp. 545-553 ◽  
Author(s):  
Ruben Nogueiras ◽  
Sulay Tovar ◽  
Sharon E Mitchell ◽  
Perry Barrett ◽  
D Vernon Rayner ◽  
...  
Keyword(s):  
Gene Expression ◽  
Energy Balance ◽  
Negative Energy ◽  
Negative Energy Balance ◽  
Pars Tuberalis ◽  
Dependent Manner ◽  
Sprague Dawley ◽  
Leptin Receptors ◽  
Sprague Dawley Rats ◽  
Lh Release

Central neuromedin U (NMU) functions in energy balance, the hypothalamic–pituitary–adrenal axis, LH release and circadian rhythmicity. In rats, high levels of NMU occur in the hypothalamic suprachiasmatic nuclei and the pars tuberalis of the pituitary. NMU expression in the pars tuberalis appears to be downregulated in the Zucker fatty (fa/fa) rat, lacking functional leptin receptors. In contrast, in the dorsomedial (DMH) nuclei of the mouse, NMU expression is higher in the ob/ob mouse, lacking leptin, and is upregulated by fasting. However, leptin appears not to change NMU gene expression in either the mouse DMH or the rat pars tuberalis. Thus, the present study aims to better identify factors influencing central NMU expression in the rat pars tuberalis. Sprague–Dawley rats were fasted and/or challenged with intracerebroventricular leptin or ghrelin and gene expression was measured using real-time reverse transcriptase-PCR and quantitative in situ hybridisation with riboprobes specific for NMU and NMU receptor (NMU-R2). NMU expression in the rat pars tuberalis was elevated by fasting. Ghrelin administration had no effect on the level of NMU expression, but leptin was found to diminish the expression in a concentration- and time-dependent manner. NMU-R2 expression was unchanged in any of the groups measured. These results suggest that NMU expression in rat pars tuberalis is upregulated in states of negative energy balance, and this may be mediated indirectly by changes in leptin levels. These results demonstrate a link between energy balance and NMU expression in the pars tuberalis of the pituitary.

scholarly journals Energy Balance Indicators during the Transition Period and Early Lactation of Purebred Holstein and Simmental Cows and Their Crosses

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 309
Author(s):  
Deise Aline Knob ◽  
André Thaler Neto ◽  
Helen Schweizer ◽  
Anna C. Weigand ◽  
Roberto Kappes ◽  
...  
Keyword(s):  
Energy Balance ◽  
Milk Yield ◽  
Milk Composition ◽  
Negative Energy ◽  
The Other ◽  
Negative Energy Balance ◽  
Metabolic Energy ◽  
Genetic Groups ◽  
Significant Difference ◽  
Fat Thickness

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.

scholarly journals Metabolic Adaptations to Dynamic Energy Requirements during Lactation and Pregnancy in Dairy Cows with Varying Proportions of Holstein and Simmental Breed

Proceedings ◽  
2020 ◽  
Vol 73 (1) ◽  
pp. 9
Author(s):  
Deise Aline Knob ◽  
André Thaler Neto ◽  
Helen Schweizer ◽  
Anna Weigand ◽  
Roberto Kappes ◽  
...  
Keyword(s):  
Energy Balance ◽  
Dairy Cows ◽  
Fixed Effects ◽  
Mixed Model ◽  
Negative Energy ◽  
Negative Energy Balance ◽  
Repeated Measure ◽  
Holstein Cows ◽  
Mixed Model Analysis ◽  
Genetic Groups

Depending on the breed or crossbreed line, cows have to cope with a more or less severe negative energy balance during the period of high milk yields in early lactation, which can be detected by beta-hydroxybutyrate (BHBA) and non-esterified fatty acids (NEFAs) in blood. Preventing cows from undergoing a severe negative energy balance by breeding and/or feeding measures is likely to be supported by the public and may help to improve the sustainability of milk production. The aim was to compare BHBA and NEFA concentrations in the blood of Holstein and Simmental cows and their crosses during the prepartum period until the end of lactation. 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), F1 crossbreds (50% Holstein, 50% Simmental; n = 17), R1-Sim (1–49% Holstein; n = 81) and Simmental (100% Simmental; n = 27). NEFA and BHBA were evaluated once a week between April 2018 and August 2019. 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 on cows was used. Holstein cows had higher NEFAs (0.196 ± 0.013 mmol/L), and Simmental cows had the lowest NEFA concentrations (0.147 ± 0.008 mmol/L, p = 0.03). R1-Sim, F1 and R1-Hol cows had intermediate values (0.166 ± 0.005, 0.165 ± 0.010, 0.162 ± 0.008 mmol/L; respectively). The highest NEFA value was found in the first week after calving (0.49 ± 0.013 mmol/L). BHBA did not differ among genetic groups (p = 0.1007). There was, however, an interaction between the genetic group and week (p = 0.03). While Simmental, R1-Sim and F1 cows had the highest BHBA value, the second week after calving (0.92 ± 0.07 and 1.05 ± 0.04, and 1.10 ± 0.10 mmol/L, respectively), R1-Hol and Holstein cows showed the BHBA peak at the fourth week after calving (1.16 ± 0.07 and 1.36 ± 0.12 mmol/L, respectively). Unexpectedly, Holstein cows had a high BHBA peak again at week 34 after calving (1.68 ± 0.21 mmol/L). The genetic composition of the cows affects NEFA and BHBA. Simmental and R1-Sim cows mobilize fewer body reserves after calving. Therefore, dairy cows with higher degrees of Simmental origin might be more sustainable in comparison with Holstein genetics in the present study.

scholarly journals On the modulation and maintenance of hibernation in captive dwarf lemurs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marina B. Blanco ◽  
Lydia K. Greene ◽  
Robert Schopler ◽  
Cathy V. Williams ◽  
Danielle Lynch ◽  
...  
Keyword(s):  
Food Restriction ◽  
Metabolic Disorders ◽  
Biological Rhythms ◽  
Food Ingestion ◽  
Ambient Temperatures ◽  
In Captivity ◽  
In The Wild ◽  
Cheirogaleus Medius ◽  
Save Energy ◽  
Metabolic Strategies

AbstractIn nature, photoperiod signals environmental seasonality and is a strong selective “zeitgeber” that synchronizes biological rhythms. For animals facing seasonal environmental challenges and energetic bottlenecks, daily torpor and hibernation are two metabolic strategies that can save energy. In the wild, the dwarf lemurs of Madagascar are obligate hibernators, hibernating between 3 and 7 months a year. In captivity, however, dwarf lemurs generally express torpor for periods far shorter than the hibernation season in Madagascar. We investigated whether fat-tailed dwarf lemurs (Cheirogaleus medius) housed at the Duke Lemur Center (DLC) could hibernate, by subjecting 8 individuals to husbandry conditions more in accord with those in Madagascar, including alternating photoperiods, low ambient temperatures, and food restriction. All dwarf lemurs displayed daily and multiday torpor bouts, including bouts lasting ~ 11 days. Ambient temperature was the greatest predictor of torpor bout duration, and food ingestion and night length also played a role. Unlike their wild counterparts, who rarely leave their hibernacula and do not feed during hibernation, DLC dwarf lemurs sporadically moved and ate. While demonstrating that captive dwarf lemurs are physiologically capable of hibernation, we argue that facilitating their hibernation serves both husbandry and research goals: first, it enables lemurs to express the biphasic phenotypes (fattening and fat depletion) that are characteristic of their wild conspecifics; second, by “renaturalizing” dwarf lemurs in captivity, they will emerge a better model for understanding both metabolic extremes in primates generally and metabolic disorders in humans specifically.

scholarly journals The Capacity of Holstein-Friesian and Simmental Cows to Correct a Negative Energy Balance in Relation to Their Performance Parameters, Course of Lactation, and Selected Milk Components

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1674
Author(s):  
Ilona Strączek ◽  
Krzysztof Młynek ◽  
Agata Danielewicz
Keyword(s):  
Fatty Acid ◽  
Energy Balance ◽  
Dairy Cows ◽  
Body Condition ◽  
Body Condition Score ◽  
Negative Energy ◽  
Negative Energy Balance ◽  
Holstein Friesian ◽  
Condition Score ◽  
Peak Lactation

A significant factor in improving the performance of dairy cows is their physiological ability to correct a negative energy balance (NEB). This study, using Simmental (SIM) and Holstein-Friesian (HF) cows, aimed to assess changes in NEB (non-esterified fatty acid; body condition score; and C16:0, C18:0, and C18:1) and its effect on the metabolic efficiency of the liver (β-hydroxybutyrate and urea). The effects of NEB on daily yield, production at peak lactation and its duration, and changes in selected milk components were assessed during complete lactation. Up to peak lactation, the loss of the body condition score was similar in both breeds. Subsequently, SIM cows more efficiently restored their BCS. HF cows reached peak lactation faster and with a higher milk yield, but they were less able to correct NEB. During lactation, their non-esterified fatty acid, β-hydroxybutyrate, C16:0, C18:0, C18:1, and urea levels were persistently higher, which may indicate less efficient liver function during NEB. The dynamics of NEB were linked to levels of leptin, which has anorectic effects. Its content was usually higher in HF cows and during intensive lactogenesis. An effective response to NEB may be exploited to improve the production and nutritional properties of milk. In the long term, it may extend dairy cows’ productive life and increase lifetime yield.

scholarly journals The EnergyKids Pilot Study: Comparing Energy Balance of Primary School Children during School and Summer Camp

Nutrients ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 92
Author(s):  
Cinzia Franchini ◽  
Alice Rosi ◽  
Cristian Ricci ◽  
Francesca Scazzina
Keyword(s):  
Physical Activity ◽  
Energy Balance ◽  
Weight Status ◽  
Summer Camp ◽  
Negative Energy ◽  
Primary School Children ◽  
Food Diary ◽  
Activity Tracker ◽  
School Time ◽  
Study Participants

Children’s energy requirements may vary during school and summer camp days. To evaluate energy balance during these two periods, seventy-eight children (45% females, 8–10 years) living in Parma, Italy, were enrolled in this observational study. Participants completed a 3-day food diary and wore an activity tracker for three consecutive days during a school- and a summer camp-week to estimate energy intake (EI) and energy expenditure (TEE). Height and body weight were measured at the beginning of each period to define children’s weight status. BMI and EI (school: 1692 ± 265 kcal/day; summer camp: 1738 ± 262 kcal/day) were similar during both periods. Both physical activity and TEE (summer camp: 1948 ± 312; school: 1704 ± 263 kcal/day) were higher during summer camp compared to school time. Therefore, energy balance was more negative during summer camp (−209 ± 366 kcal/day) compared to school time (−12 ± 331 kcal/day). Similar results were observed when males and females were analyzed separately but, comparing the sexes, males had a higher TEE and a more negative energy balance than females, during both periods. The results strongly suggest that an accurate evaluation of children’s energy balance, that considers both diet and physical activity, is needed when planning adequate diets for different situations.

Investigation of Thermal Effects in Direct Driven Hydraulic System for Off-Road Machinery

2016 ◽  
Author(s):  
Niko Karlén ◽  
Tatiana Minav ◽  
Matti Pietola
Keyword(s):  
Energy Efficiency ◽  
Hydraulic System ◽  
Energy Savings ◽  
Mechanical Energy ◽  
Hydraulic Model ◽  
Energy Losses ◽  
Total Efficiency ◽  
Ambient Temperatures ◽  
Wheel Loaders ◽  
Save Energy

Several types of off-road machinery, such as industrial trucks, forklifts, excavators, mobile cranes, and wheel loaders, are set to be operated in environments which can differ considerably from each other. This sets certain limits for both the drive transmissions and working hydraulics of these machines. The ambient temperature must be taken into account when selecting the hydraulic fluid since the viscosity and density of the fluid are changing at different operating temperatures. In addition to the temperature, energy efficiency can also be a problem in off-road machinery. In most off-road machines, diesel engines are employed to produce mechanical energy. However, there are energy losses during the working process, which causes inefficiency in produced energy. For better energy efficiency, hybridization in off-road machinery is an effective method to decrease fuel consumption and increase energy savings. One of the possible methods to save energy with hybrids is energy regeneration. However, it means that the basic hydraulic system inside off-road machinery needs to be modified. One solution for this is to utilize zonal or decentralized approach by means of direct driven hydraulic (DDH) system. This paper aims to investigate a DDH system for off-road machinery by means of modelling and analyzing the effect of the temperature. In the direct-driven hydraulic system, the actuator is controlled directly by the hydraulic pump which is operated by the electric motor. Specifically, it is a valveless closed-loop hydraulic system. Thus, there will be no energy losses caused by the valves, and the total efficiency is assumed to be significantly higher. In order to examine the DDH system, a thermo-hydraulic model was created. Additionally, a thermal camera was utilized in order to illustrate the temperature changes in the components of the DDH system. To reproduce the action of the system in different circumstances DDH system was run at different ambient temperatures, and the component temperatures in the system were measured and saved for the analysis. The thermo hydraulic model was proven capable to follow the general trend of heating up.

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