ANSC315 exam 1

Dry Matter (DM)

The weight of a feedstuff after all moisture has been removed.

As Fed (AF) Basis

The nutrient content of a feedstuff in its natural state, including moisture.

Dry Matter Basis

The nutrient content of a feedstuff expressed as a percentage of the dry matter.

Dimensional Analysis

A method of problem-solving that focuses on the units of measurement to ensure calculations are set up correctly and the final answer has the desired units.

Essential Amino Acids

Amino acids that cannot be synthesized by the animal in sufficient quantities and must be supplied in the diet.

Nonessential Amino Acids

Amino acids that can be synthesized by the animal, though they are still needed.

Crude Protein (CP)

An estimate of the total protein content of a feed, calculated by multiplying the nitrogen content by a factor (usually 6.25).

Limiting Amino Acid

The essential amino acid present in the lowest quantity relative to the animal's requirement, thus limiting protein synthesis.

Rumen Degradable Protein (RDP)

Protein that is broken down by microbes in the rumen.

Rumen Undegraded Protein (RUP)

Protein that passes through the rumen without being significantly degraded and is digested in the small intestine.

Metabolizable Protein (MP)

The true protein available to the animal for metabolic processes.

Neutral Detergent Fiber (NDF)

Represents the total fiber content of a feed, including cellulose, hemicellulose, and lignin.

Acid Detergent Fiber (ADF)

Represents the less digestible fiber components, primarily cellulose and lignin.

Relative Feed Value (RFV)

An index used primarily for legume forages to estimate their quality based on digestibility and intake potential.

Total Digestible Nutrients (TDN)

A measure of the total digestible energy content of a feed.

Bloat

A condition in ruminants characterized by the excessive accumulation of gas in the rumen.

Feed Sorting

The selective consumption of certain feed components over others by animals.

Proximate Analysis

A traditional method of feed analysis that separates feed into six fractions: DM, ash, CP, crude fat, CF, and NFE.

Near-Infrared Reflectance Spectroscopy (NIRS)

An analytical technique that uses the near-infrared region of the electromagnetic spectrum to predict nutrient composition.

Bushel

A unit of volume commonly used for cereal grains.

Lysine

An example of a limiting amino acid in poultry and swine, often required in higher amounts in their diets to support growth and protein synthesis.

Importance of Dry Matter in Diet Formulation

Understanding dry matter is crucial for accurately formulating and evaluating animal diets since it allows for the comparison of nutrient concentrations without the influence of water content.

As-Fed vs. Dry Matter Basis

Expressing nutrient content on an as-fed basis includes moisture, affecting feeding decisions; using dry matter basis standardizes comparisons and ensures accurate nutrient intake assessments.

Proximate Analysis System

A traditional method separating feed into six fractions (DM, ash, CP, crude fat, CF, NFE) to estimate nutrient composition.

Detergent Fiber System

A system evaluating feed based on Neutral Detergent Fiber (NDF) and Acid Detergent Fiber (ADF) to predict digestibility and assess fiber quality.

Strengths of Proximate Analysis

Advantageous for quick assessment of nutrient fractions; however, it may not accurately reflect digestibility or energy content.

Limitations of Proximate Analysis

Can oversimplify complex components and ignore interactions between nutrients that influence feed value.

Strengths of Detergent Fiber System

More accurately predicts digestibility of forages based on fiber types; useful for discerning forage quality.

Limitations of Detergent Fiber System

May not fully account for non-fibrous energy sources and other digestible nutrients.

Factors Influencing Voluntary Feed Intake

Voluntary feed intake is influenced by animal-related factors (physiological state, size) and feed-related factors (physical form, nutrient composition, palatability).

Short-Term Intake Regulation

Short-term mechanisms control intake during feeding based on gut fill and nutrient signals, impacting immediate feeding behavior.

Long-Term Intake Regulation

Long-term mechanisms involve energy balance and nutrient needs, affecting overall feed consumption patterns over time.

Rumen Degradable Protein (RDP)

Protein fraction that is broken down in the rumen, providing amino acids for microbial protein synthesis.

Rumen Undegraded Protein (RUP)

Protein that escapes rumen degradation and is digested in the small intestine, crucial for meeting amino acid requirements.

Key Considerations in Ruminant vs. Non-Ruminant Diets

Ruminants require both RDP and RUP for microbial protein synthesis and tissue development, while non-ruminants primarily rely on RUP for protein needs.

Relative Feed Value (RFV)

An index estimating forage quality based on its digestibility and intake potential, helping in ration balancing for livestock.

Relative Forage Quality (RFQ)

A comprehensive index considering both nutrient quality and the physical attributes of forages, guiding feeding strategies.

GRAS

Generally Recognized As Safe; a designation for substances that are considered safe for consumption based on a long history of common use in food or on the results of scientific research.

Difference between Relative Feed Value (RFV) and Relative Forage Quality (RFQ)

RFV estimates forage quality based on digestible dry matter (DDM) and dry matter intake potential (DMI), primarily for legumes, while RFQ incorporates fiber digestibility to provide a more accurate measure of intake and total digestible nutrients (TDN), making it more effective for comparing various forage types.

Two methods used to measure nitrogen content in a feed

Dumas and Kjedahl

The Atwater factors are

a set of values estimating the energy content of macronutrients, per 1 g: 4 kcal CHO, 4 kcal protein, 9 kcal fat