Energy Measurement and Net Energy Systems

These flashcards cover key terminology related to energy measurement in animal nutrition, focusing on the net energy system and methodologies used for assessing energy values in diets.

Net Energy (NE)

The energy available from feed after accounting for energy lost in digestion and metabolism.

Gross Energy (GE)

The total energy content of feed, determined using bomb calorimetry.

Digestible Energy (DE)

The portion of gross energy that is digestible (DE = GE - Fecal Energy).

Metabolizable Energy (ME)

The energy available after subtracting methane and urinary energy from digestible energy (ME = DE - MtE - UE).

Calorimetry

A process used to measure the heat released during a chemical reaction or physical process, crucial in determining energy values.

Bomb Calorimetry

A method used to measure the gross energy content of feed.

Heat Increment (HI)

The energy lost as heat during the digestion and metabolism of feed.

Methane Energy (MtE)

Energy associated with the production of methane during digestion, used in calculating metabolizable energy.

Retained Energy (RE)

The energy stored in the animal’s body through growth, lactation, and conceptus.

Maintenance Energy (HE)

Energy required for an animal to maintain its basic physiological functions at rest.

Basal Metabolic Rate (BMR)

Heat production measured during fasting and minimal activity, indicating energy expenditure at rest.

Thermoregulation

The energy expended for maintaining body temperature within a certain range.

Activity Budget

A calculation that estimates energy expenditure based on the type and duration of physical activities.

Comparative Slaughter Technique

A method used to measure retained energy by comparing the energy content of an animal's body before and after the feeding trial.

Enthalpy of Reaction (ΔrH)

The total heat content change during a chemical reaction, important for measuring fermentation heat.