Energy Systems and Calorimetry

A series of flashcards covering key concepts related to energy systems, dietary estimation, and calorimetry techniques used in animal science.

Net Energy (NE)

The energy that is available to an animal after accounting for energy losses from maintenance, reproduction, lactation, etc.

Gross Energy (GE)

The total energy content of a feed before digestion.

Digestible Energy (DE)

The portion of gross energy that is digested and absorbed by an animal.

Metabolizable Energy (ME)

The energy available after accounting for energy lost in feces, urine, and gases.

Calorimetry

The science of measuring heat energy or calorific value of substances.

Adiabatic Bomb Calorimeter

A device used to measure the heat of combustion of a substance without any heat transfer to the surroundings.

Isothermal Calorimeter

Equipment used to measure the heat production in living systems, maintaining a constant temperature.

Endogenous Secretions

Substances produced within the body that are secreted into the digestive tract.

Efficiency of Energy Use

Ratio of useful energy output to energy input in an animal's metabolism.

NASEM equations

Equations developed for estimating energy values for animal diets, used to calculate DE, ME, and NE.

Heat Production (dQ/dt)

The rate at which heat is produced in an organism or material.

Calibration of Calorimeters

Process to ensure that calorimeters provide accurate energy measurements based on known standards.

Microbial Fecal Nitrogen

Nitrogen from microbes present in feces, significant for understanding energy losses in animals.

Thermoneutral Temperature

The environmental temperature at which an animal does not need to expend energy for thermoregulation.

Chemical Composition

The elemental and molecular makeup of a feed and its nutrients which affect digestion and energy estimation.

Prediction of Digestible Energy

The process of estimating how much energy from feed can be absorb by an animal, often using empirical formulas.

Open-Circuit Respiration Chamber

A system where gas is drawn in from and exhausted to the environment for measuring respiratory gas exchanges.

Closed-Circuit System

A setup where gas is reused within a sealed environment for metabolic measurement.

Indirect Calorimetry

A method measuring metabolic rate by analyzing respiratory gases rather than direct heat measurements.

Feed Type Impact

Influence of the specific feed used on energy values and digestion in animals.