ANSC 318: EXAM 1
40 Cards in this Set
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Definition of feed
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a material which, after ingestion by an animal is capable of being digested, absorbed and utilized.
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Definition of nutrient
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A component of a feed that aids in the support of life
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Nutrients
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Water and Dry Matter
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The organic parts of dry matter
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carbs, lipids, proteins, vitamins
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Which composition of feedstuffs (%) is usually the highest?
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Carbohydrate
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Which composition of feedstuffs (%) is usually low?
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Fat
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Which composition of feedstuffs (%) is variable?
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protein
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Which feedstuff composition (%) is the exemption for fat?
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Soybean meal, it is high in fat
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What composition of animal products (%) is low?
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Carbohydrates are low
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what composition of animal products (%) is high?
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Fat is usually high
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What composition of animal products (%) is variable?
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Protein is variable
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General Comments about Water
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it is often overlooked as a nutrient
essential nutrient to support: Metabolism and Temperature Regulation
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Sources of water include
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Drinking, contained in feed, metabolic
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How does forage moisture content effect water intake?
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As water intake (liters of water per kg of forage DM) will decrease as the moisture content of forage (%) increases.
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How does the level of production ans environment effect water requirements?
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As water intake (kg/day) increases so does temperature (C).
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General Comments about Carbohydrates?
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They are the main storage form of photosynthetic energy in plants
1:2:1 ratio of C:H:O
Comprise approximately 50 to 85% of the dry matter of typical animal feeds
The nutritive value os based upon the glycosidic bonds between sugar molecules
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Factors that affect the nutrient concentrations of feeds
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Location, management practices, soil fertility, climate, plant species, maturity of plant
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Methods used to evaluate feedstuffs
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Proximate analysis, Van Soest Analysis, Specific chemical analysis, NIRS, Animal-Based Methods, Microbiological methods
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Proximate Analysis System
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Most common, do not have to conduct a metabolism trial or feeding experiment, it is the basis for the total digestible nutrient (TDN) system.
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The Six different analysis used in the Proximate Analysis System
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Water
Crude Protein
Crude Fat (Ether Extract)
Ash
Crude Fiber
Nitrogen-free extract
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The weakness of the Crude Protein analysis
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not all protein contains 16% nitrogen
nitrogen analysis does not distinguish between non-protein nitrogen (NPN) (ex: urea & true protein).
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Primary weakness of proximate analysis system
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Separation of CHO into the CF and NFE is inaccurate and inconsistent
CF assay does not recover 100% of cellulose, hemicellulose, and lignin
some fiber components end up in the NFE fraction
Variation exists between plants in recovery of fiber components
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Components of Ash
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Macrominerals and Microminerals
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Components of Crude Protein
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Protein, Amino Acids, Amines(NPN), NPN. Nucleic Acids, Nitrates (NPN), B Vitamins
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Components of Crude Fat
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Fats, oils, waxes, organic acids, pigments, fat-soluble vitamins
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Components of Crude Fiber
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Cellulose, Hemicellulose, lignin
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Components of Nitrogen-free extract
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Sugars, starch, pigments, fructans, pectins, some cellulose, some hemicellulose, some lignin
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Background of Van Soest
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more accurate system to analyze CHO fraction
Uses detergents to solubilize various portions of plant material
replaced crude fiber analysis
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Neutral detergent fiber
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primarily cellulose, hemicellulose, lignin
total fiber or cell wall content in feeds
associated with feed intake potential, esp in the rumen
High NDF, low intake
Cellulose, Hemicellulose, Lignin
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Acid Detergent Fiber
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Consist primarily of cellulose and lignin
Highly associated with digestibility of forages
Feeds with high ADF, Less digestible and less energy
Cellulose, Lignin
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Cell Contents (non-fiber components)
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Not a chemical assay
Calculated cell contents (DM)=100-NDF(DM)
Lipids, Sugars, Pectins, Soluble protein, starch, Water- soluble matter
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Why is NDF always higher than ADF?
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Due to the hemicellulose content. CF=NDF (ideally)
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Heat Damaged Forages
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Excess heat from bailing hay that is too wet can impair forage protein quality, as a result of Browning Reactions
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What is a Browning Reaction?
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Heat-induced chemical reactions between protein (amino acids) and sugars that render the protein to be less digestible
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What does ADF-CP analyze?
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A chemical assay used to measure heat-damaged protein. How much Nitrogen is bound to fiber (hemicellulose and cellulose).
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Background on the NIRS analysis
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Method of analysis to rapidly and reproducible measure the chemical components of feed samples with little or no sample preparation
Based on each major chemical component in a feed has a unique near infrared absorption spectrum that can be used to differentiate one chemical component fro…
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Advantages of the NIRS
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fast, simple preparation, multiplicity of analyses with one operation, non-consumption of sample, high precision, environmentally friendly.
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Disadvantages of NIRS analysis
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Method is dependent of calibration procedures (main one), Doesn't work very well on minerals and vitamins, doesn't do well to analyse ration
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Chemical evaluation
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potential value of a feed can be measured by chemical analysis
actual or useful value of a feed to an animal can be determined only after making allowances for losses that occur. Digestion (enzymes/ferment), absorption (end products), and metabolism,.
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Nutrient Digestibility
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Digestibility of a feed is defined as that proportion of feed that is not excreted in the feces and is thus assumed to be absorbed by the animal.
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Exam 1 Flashcards