Feed and Food Analyses - Animal Sciences 223

This set of vocabulary flashcards covers the key concepts of proximate analysis, nutritional information sources, and laboratory measurement techniques for animal feed and food analysis.

Proximate Analyses

A classical, sequenced approach to analyzing diets and ingredients that categorizes chemical components into groups rather than measuring individual nutrients directly.

Weende Agricultural Experiment Station

The location in Germany where proximate analysis was established in 1860 by Henneberg and Stohman.

Near-infrared spectroscopy (NIRS)

An analytical technology capable of generating real-time data on ingredient/diet composition, though it must be calibrated using wet chemistry.

Wet chemistry

The ‘gold standard’ of analytical techniques used to calibrate NIRS machines.

Gravimetric methods

Analytical procedures based on the quantitative determination of an analyte based on the mass of a solid.

Dry Matter (DM)

The component of a sample remaining after water is removed, often determined by 'loss on drying' methods.

Indirect DM determination

A method based on the evaporation of water where a sample is subjected to heat ($105^{\circ}\text{C}$ for 12-16 hours) and the measured weight loss is assumed to be water.

Crude Protein (CP)

An estimate of protein content based on measuring nitrogen concentration. The formula used is $\text{\% N} \times 6.25 = \text{\% CP}$.

Kjeldahl procedure

The classic analytical method for measuring organic nitrogen through digestion in hot sulfuric acid followed by distillation and titration.

Combustion method

A method for measuring total nitrogen by heating a sample to temperatures above $950^{\circ}\text{C}$ in pure $O_2$.

Ether Extract (EE)

Also known as crude fat, this represents the lipid components removed from a sample by repeatedly refluxing diethyl ether through it in a Soxhlet apparatus.

Ash

The inorganic material or mineral content of a sample, measured by burning the sample in a muffle furnace at $500-600^{\circ}\text{C}$ overnight to remove all organic compounds.

Organic Matter (OM)

The portion of the dry matter that is not mineral, calculated as $\text{OM} = \text{DM} - \text{ash}$.

Crude Fiber (CF)

A measure of cellulose, hemicellulose, and lignin obtained by boiling a sample in acidic and then alkaline solutions to simulate digestion.

Van Soest Method

A system of fiber analysis involving extraction and filtration to determine NDF, ADF, and ADL, which is considered superior to the Crude Fiber method.

Neutral Detergent Fiber (NDF)

A component of the Van Soest method representing hemicellulose, cellulose, and lignin.

Acid Detergent Fiber (ADF)

A component of the Van Soest method representing cellulose and lignin.

Nitrogen-free Extract (NFE)

A calculated value theoretically representing digestible carbohydrates like starch and sugars. It is determined by the formula: $\text{NFE} = 100 - (\text{moisture} + \text{CP} + \text{EE} + \text{CF} + \text{ash})$.

Total Dietary Fiber (TDF)

The gold standard for fiber analysis, considered superior to both Crude Fiber and the Van Soest method.

Soxhlet apparatus

A specific piece of glassware used in the ether extract procedure to reflux diethyl ether through a sample packet.