scholarly journals The Energy Requirements and Performance of Growing Chickens and Turkeys as Affected by Environmental Temperature

1980 ◽  
Vol 59 (10) ◽  
pp. 2290-2299 ◽  
Author(s):  
S. HURWITZ ◽  
M. WEISELBERG ◽  
U. EISNER ◽  
I. BARTOV ◽  
G. RIESENFELD ◽  
...  
2001 ◽  
Vol 26 (S1) ◽  
pp. S202-S219 ◽  
Author(s):  
Louise M. Burke

Each athlete has unique energy requirements, which underpin their ability to meet total nutritional goals. For everyday dietary planning and evaluation, energy requirements can be predicted via estimations of RMR and activity levels. Research methods such as indirect calorimetry and DLW allow energy requirements to be measured, and may be useful to confirm situations in which an athlete has a true energy balance anomaly. There is some evidence that individual athletes may have reduced energy requirements, although this occurs less frequently than is reported. Most self-reports of food intake substantially under-estimate energy intake, due to under-reporting or under-eating during the period of record keeping. Many athletes are over-focused on reducing body mass and body fat below levels that are consistent with long-term health and performance. Restrained eating can cause significant detrimental outcomes to body function. Leptin may be involved in modulating or mediating some of these changes. Athletes should use their energy budget to choose foods that provide macronutrient and micronutrient needs for optimal health and performance. Practical advice may help athletes to achieve energy intake challenges.


1995 ◽  
Vol 1995 ◽  
pp. 210-210
Author(s):  
J.M.F. Wilson ◽  
O.I. Southwood ◽  
H.A.M. van der Steen

The choice feeding of pigs has been shown in many experiments to allow the individual pig to express its own needs and thereby grow more efficiently and show its full potential.The objective of this experiment was to test whether pigs representing 7 distinct genotypes, including Large White, Landrace, Pietrain, Duroc and Meishan, were able to select their dietary crude protein (CP) in relation to energy requirements under a choice feeding regime, and whether these differences were related to growth and performance.


1980 ◽  
Vol 59 (10) ◽  
pp. 2322-2330 ◽  
Author(s):  
ELLEN K. WILSON ◽  
FRANK W. PIERSON ◽  
PATRICIA Y. HESTER ◽  
R.L. ADAMS ◽  
W.J. STADELMAN

Respuestas ◽  
2019 ◽  
Vol 24 (1) ◽  
pp. 56-64
Author(s):  
Carol Rosabeth Sanabria Sanabria ◽  
Carlos Hernando Higuera Sandoval

The weather factor plays an important role in the behavior and performance of asphalt mixtures as a surface layer in a flexible pavement structure, not just from the moisture, but also from the environmental temperature. Asphalt layers of the flexible pavements in Tunja city exposes daily to environmental temperature variations, which usually occur when the highest temperatures are reached during the daytime, and the lowest temperatures appear at night and early morning time. Firstly, this research is based , on the definition of the environmental temperature cycles that occur daily in Tunja City, from the analysis of the temperature series. Subsequently, the analysis was done through laboratory tests on an asphalt mix MDC-19 INVIAS type, made and compacted in the laboratory, to determine the influence of the cycles of environmental temperature on its density, stability and flow properties, during 120 daily and continuous temperature cycles, which consist of 12 hours of maximum temperature and 12 hours of minimum temperature to simulate the environmental conditions. As a result of this investigation, the presentation density is presented, presenting a tendency to increase the measurement that increases the temperature cycles and then a decrease in the briquettes of the mixture that have sometimes been until the last cycles. Variations in the resistance to deformation of the analysis mixture were obtained as the ambient temperature cycles were sometimes made, which concludes that the ambient temperature cycles have an influence on the behavior of the asphalt mixture.


1982 ◽  
Vol 26 (2) ◽  
pp. 137-141
Author(s):  
P. A. Hancock

This paper examines the effect of operator skill level upon performance in transient extreme heat. Previous work has indicated that task familiarity is beneficial in prolonging efficient performance in elevated environmental temperature. It is proposed that such familiarity is subsumed by automated responses, with respect to consistent components of individual task demands. These components, developed through consistent mapping of stimulus and response relationships, remain essentially unimpaired by the thermal stressor. In contrast, heat may induce potentially dangerous decrement in both inconsistent elements of practiced tasks and performance in novel or emergency situations. The automatic and control processing framework may be applied to performance variation under alternate environmental stressors and is of potential importance to those who have occasion to require personnel to operate in non-optimal environmental conditions.


2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 317-318
Author(s):  
Jessica L Varney ◽  
Jason W Fowler ◽  
Jordan T Weil ◽  
Charlene F Watson ◽  
Mary Ann Boggess ◽  
...  

Abstract As the pet industry continues to grow, understanding the needs of different demographics of canines is becoming increasingly important to ensure optimal nutrition. Energy requirements have been shown to vary based on individual factors, but few trials using many dogs under the same controls exist. The objective of this study was to investigate the effect of age, sex, reproductive status, body composition, and environmental temperature on the BMR of Labrador Retrievers (Labs). An open-circuit indirect calorimetry machine attached to a chamber was used to determine resting BMR in 96 Labs. Body composition in 33 Labs of varying age was determined using DXA scans to determine effect of lean/fat mass on BMR. Cooling and heating implements were applied to the chamber to determine temperature effect on BMR. Each of the following demographics were compared using a mixed model: male, female, intact, altered, young (6mo-2yo), adult (3-6yo), and senior (7yo+). Mean BMR for all dogs was 130 (27) kcal/kg0.75. Males were significantly higher at 136 (28) kcal/kg0.75 than females at 125 (25) kcal/kg0.75 (P = 0.045). Intact Labs were significantly higher at 121 (3) kcal/kg0.75 compared to altered Labs at 109 (25) kcal/kg0.75 (P < 0.001). Young and adult Labs had BMRs of 136 (19) kcal/kg0.75 and 135 (29) kcal/kg0.75, respectively, which was significantly higher than seniors at 120 (26) kcal/kg0.75. Body composition comparisons showed significant negative linear relationships between BMR and fat mass (P < 0.001) and positive linear relationships between BMR and lean mass (P < 0.001). BMR was found to have a negative linear relationship (R2=0.51) from cool to warm temperatures but was elevated at both cold (< 5°C) and hot (>35°C) temperatures (P < 0.001). The determination of energy requirements found in this study prove useful as the pet industry develops diets specific to the needs of different demographics of canines.


2019 ◽  
Vol 17 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Daniel Rojas-Valverde ◽  
Jose Alexis Ugalde Ramírez ◽  
Braulio Sánchez-Ureña ◽  
Randall Gutiérrez-Vargas

The purpose of this study was to explore the influence of altitude and environmental temperature on muscle mechanical and functional activation after 30' Time Trial run (30' TT). Twenty physical active males (Age= 20.4 ±3.21 years, VO2max= 47.2 ±5.2 ml/kg/min) performed a 30' TT in three different conditions of altitude and temperature: Control Condition [CC] (1137 m.a.s.l. at 26 ±1.5°C), Heat-Low Condition [HLC] (3 m.a.s.l. at 30.5 ±0.6°C), and Cool-High Condition [CHC] (2369 m.a.s.l. at 14.2 ±0.6°C). Tensiomyography (TMG), Countermovement Jump (CMJ), and Delayed Onset Muscle Soreness (DOMS) were measured pre and post running. During the 30' TT, distance, speed, heart rate (HR), rate of perceived exertion (RPE), and thermal index (WBGT) were measured. Results show a significant decrease in body weight and a significant increase in DOMS and jump height in CMJ after running in each condition. TMG responses increased maximum radial muscle displacement (Dm) and decreased muscle contraction time (Tc) both rectus and biceps femoris muscles after running. During the 30' TT, the results did not show a significant difference in RPE, HR, distance, and speed among conditions. In conclusion, altitude and temperature seem not to significantly affect the mechanical and functional responses 30' TT, despite the tendency of HLC to decrease both activation and performance.


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