Exam 1 Flashcards
103 Cards in this Set
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What are the components of animal feed?
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water and dry matter (organic and inorganic matter)
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What are the components of organic matter?
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carbohydrates, lipids, proteins, vitamins
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How do pigs, horses, and cattle digest fiber CHO?
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pigs: limited fermentation in the LI
horses: fermentation in LIcattle: fermentation in rumen
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How do pigs, horses, and cattle digest starch CHO?
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pigs: enzymatic in SI, some fermentation in LI
horses: enzymatic in SI, some fermentation in LIcattle: fermentation in rumen, some enzymatic in SI
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How do pigs, horses, and cattle digest protein?
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pigs: enzymatic in SI
horses: enzymatic in SIcattle: fermentation in rumen, some enzymatic in SI
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How do pigs, horses, and cattle digest lipids?
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pigs: enzymatic in SI
horses: enzymatic in SIfermentation in rumen, some enzymatic in SI
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What is the largest component of the pig's digestive system? The smallest?
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largest: SI
smallest: cecum
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What is the largest component of the horse's digestive system? The smallest?
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largest: colon
smallest: stomach
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What is the largest component of the cow's digestive system? The smallest?
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largest: rumen
smallest: cecum
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What are the four compartments of the rumen?
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rumen, reticulum, omasum, abomasum
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What is a commonly overlooked nutrient and what does it do?
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water
it 's essential to support body metabolism (biochemical reactions) and regulates body temperature
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What are sources for water?
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drinking water, water in feed, metabolic water (water of oxidation)
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What is the main storage form of photosynthetic energy in plants?
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carbohydrates
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What does the nutritive value of carbohydrates depend on?
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the ability for the animal to cleave glycosidic bonds between sugar molecules.
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What do carbohydrates consist of?
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starch, sugars, pectin, lignin, cellulose, hemicellulose
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What are some monosaccharides?
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glucose, fructose, galactose, mannose (hexoses)
arabinose, xylose (pentoses)
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What are some disaccharides?
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sucrose, lactose, maltose (alpha linkage), cellubiose (beta linkage)
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What are some polysaccharides?
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araban, xylan, starch, glycogen, fructans, cellulose
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What is lignin?
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not a carbohydrate; is a polymer closely associated with structural CHO
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What are organic compounds insoluble in water but soluble in organic solvents?
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lipids
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How much more are lipids more energy dense than CHO and protein?
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2.25 x
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What are the classification of lipids:
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true fats, waxes (less digestible than true fats)
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Where are fatty acids absorbed?
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the lymph system
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What is the structure of protein?
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amino acids linked by peptide bonds
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What is the classification of proteins?
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simple, fibrous, conjugated
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What is a true protein?
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protein only composed of amino acids
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What is a nonprotein nitrogen (NPN)?
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not a true protein in nature but contain N and can be converted to protein by bacterial action
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What are essential amino acids?
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amino acids that are not synthesized in animal tissues in sufficient amounts to meed metabolic needs
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What is a bypass protein?
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protein that escapes rumen digestion
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How do newborn animals digest protein?
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intact proteins can be absorbed by pinocytosis for a limited amount of time
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What is DIP?
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Degraded intake protein; protein that is hydrolyzed in the rumen
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What is UIP?
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undegraded intake protein; protein that goes to the SI
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What are 3 important macrominerals?
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calcium, phosphorous, sodium
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What are vitamins?
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organic components that are present in small amounts, are needed for metabolic activity and cannot be synthesized by the animal. Requirements must be met by diet or microbial synthesis.
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What are some fat soluble vitamins?
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A, D, E, K
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What do fat soluble vitamins do and how are they excreted?
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Regulate metabolism of structural units
excreted in feces
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What do water soluble vitamins do and how are they excreted?
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regulate the transfer of energy
excreted in feces and urine
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What vitamins can rumen microbes synthesis?
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water soluble vitamins and K (the only fat soluble vitamin)
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How does the value of feed quality vary?
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by animal species and physiological function (ex. milk/ egg/ meat production)
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What are factors that affect the nutrient concentrations of feeds?
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geographical location, method of harvest/ storage, soil fertility, climate, plant species, maturity of plant
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What are some types of chemical analysis?
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proximate system
van soest systemspecific systems (ex. vitamins, minerals)
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What is NIR?
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Near Infrared Reflectance
(nondestructive)
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What are animal based methods of feedstuff evaluation?
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metabolism trials
feeding experimentsin vivo methods (cannula)
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What are microbiological methods for feedstuff evaluation?
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nylon bag procedure
in vitro procedures
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What is the proximate analysis system?
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most common method used
done without having to conduct metabolism trials or feeding experimentsis the basis of total digestible nutrient (TDN) system to evaluate energy availability
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What does the proximate system separate in a feed sample?
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6 fractions:
watercrude protein (16% N or 6.25) , 2 methods; Kjeldahl and Leco)crude fat/ ether extraction (fat soluble is separated)ash (inorganic/minerals)crude fibernitrogen free extract (NFE: 100- (CP+CF+EE+ash))
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What are the weaknesses of the proximate analysis system?
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not all protein contains 16% N
nitrogen analysis doesn't distinguish between NPN and true proteinseparation of CHO is inaccurate and inconsistentCF assay doesn't recover 100% of the cellulose, hemicellulose, and ligninvariation between plants in the recovery of fiber components
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What is the Van Soest system?
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more accurate at analyzing the CHO
uses detergents to solubilize various portions of plant materiallargely replaced the CF analysis (but CF is still used)
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What is the natural detergent fiber (NDF) component of the Van Soest system?
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consist of hemicellulose, cellulose, lignin)
represents total fiber or cell wall content of feedhigh NDF= lower feed intake
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What is the acid detergent fiber (ADF) component of the Van Soest system?
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consist of cellulose and lignin
associated with the ingestibility of forageshigh ADF= less digestible, less energy
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What are the 3 components of the Van Soest system?
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NDF, ADF, cell contents (sugars, lipids, pectins, soluble protein, starch)
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What can impact protein quality as a result of Mailard reactions?
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excess heat from bailing hay that is too wet or ensilling hay that is too dry
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What is a chemical assay used to measure heat damaged protein?
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ADF-CP
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What is a Mailard reaction?
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heat induced chemical reactions between amino acids/ protein and sugars that render the protein to be less digestible
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What is the NIR method?
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rapidly measures the chemical components of feed samples with little or no sample preparation; based on unique infrared absorption spectrum for differentiation
primary absorbers are vibrational motions of H attached to C, N, or O atoms
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What are some advantages of NIR?
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spped, simplicity, multiplicity of analysis with one operation, non consumption of sample, high precision, environmentally friendly
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What are some disadvantages of NIR?
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method dependent on calibration procedures, calibration requires conducts anaylses on 100s of samples, limited to availability and accuracy of calibration data bases, lack of sensitivity of analysis for minor constituents (ex. lysine), expensive
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What is digestibility of a feed?
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the proportion of feed that is not excreted by the feces and is thus assumed to be absorbed by the animal
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How is potential value of a feed measured?
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by chemical analysis
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What is apparent digestibility?
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named that because not all fecal matter is excreted by an animal represents undigested feed. Fecal material is undigested feed and non feed materia/ endogenous fecal material like undigested microbes, digestive enzymes and mucous, and sloughed intestinal cells
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How do you determine nutrient digestibility?
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conventional digestion trial: accurate
objective digestion trial: quantify nutrients consumed and nutrients excreted in feces for a particular feed or diet in a given period of time
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How do you calculate apparent nutrient digestibility?
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nutrients in- nutrients out/ nutrients in x 100
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What are factors that affect apparent digestibility?
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The nutrient composition of feed (chemical composition varies) and forage maturity (as plant matures, digestibility decreases)
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Which is better at predicting digestibility; NDF or ADF?
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ADF
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What is the associative effects on digestibility?
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refers to the differences in digestibility of feeds fed as components of a mixed diet compared to feeds fed alone. occur primarily in ruminants when fed at high levels of intake.
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What is the negative effect?
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sometimes digestibility decreases when two feeds are combined
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what is an example of the negative effect?
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silage and grain mix; depression in digestibility occurs due to incomplete starch digestion in diets with mixtures of corn grain and corn silage
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What feed processing factors affect apparent digestibility?
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grinding/ pelleting forage will decrease digestibility
prcoessing forage will decrease time available for digestion processing grain will increase digestion
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What happens when an animal eats processed forage?
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it eats more forage because it doesn't realize that's it's full
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How does temperature affect apparent digestibility?
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digestibility is decreased with cold temperature in all animals
digestibility is not affected by hot temperatures
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What is TDN?
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total digestible nutrients
the general measure of a feed's energy valuerequires measurement of nutrient digestibility coefficient
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What is the weakness of the TDN system?
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does not account for energy losses (heat, urine, feces, methane)
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What feed is gaseous energy and heat loss greater in?
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...
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What type of feed does TDN values overestimate?
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roughage
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What is feed energy?
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not a nutrient but rather a property of nutrients
it is the most important item to consider in nutrition
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What are nutrients that supply energy?
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...
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What is feed energy used for?
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mechanical/ chemical work, synthesis of enzymes and hormones, maintenance of homeothermy, synthesis of animal products
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How is feed energy determined?
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it is converted to heat and measured (in calories)
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What is gross energy?
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the potential energy of a feed
also referred to as the heat of combustionvery little diff between the GE value of feeds (ex. hay vs corn; similar composition of nutrients)
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How is GE measured?
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the heat from complete oxidation of a feed to CO2 and H2O in a bomb calorimeter is measured
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What is digestible energy?
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similar to TDN, does not account for losses in heat, urine, and gas
GE- FE (fecal energy)= DEoverestimates usual energy value of roughages relative to grains
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What is metabolizable energy?
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ME= DE- urine energy (UE)- gaseous energy (GPD)
ME is more accurate than DE in predicting a feed's effective energy value
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What is net energy?
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ME- HI (heat increment)= NE
represents the portion of the GE that is actually useful for the body; energy that is directly available to perform metabolic functionsmost accurate estimate of a feed's effective energy value
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What is heat of nutrient metabolism?
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heat associated with the metabolic processes of product formation
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What represents the inefficiency of ME use?
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HI (heat increment), useful only during cold stress
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What is NEm?
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NE used to maintain body tissue
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What is NEg?
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NE used to deposit lean and adipose tissue
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What is NEl
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...
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What are methods used to measure NE value?
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whole-animal calorimetry (for dairy cattle)
comparative slaughter balance (for beef cattle)
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What is whole animal calorimetry?
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the principal that heat is generated during the oxidation of organic compounds to CO2 and H2O; the animal is put in a chamber and O2 consumption and CO2 and CH4 production is measured
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Which is more accurate at giving values of feed value, NE or DE, and why?
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NE (especially in ruminants) because DE doesn't measure losses in methane and heat
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How do you meet the protein requirements in a non ruminant?
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all essential amino acids must be supplied in the diet in correct amounts and correct proportions
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How do you meet the protein requirements in a ruminant?
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more complex; must provide nitrogen for microbial synthesis in the rumen as well as amino acids for absorption and metabolism in the small intestine
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How do you measure protein quality in non ruminants?
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protein efficiency ratio
biological valueideal protein concept
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What is PER/ Protein efficiency ratio?
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uses growth rate per unit of intake as a measure of protein quality
weight gain (g) / protein consumed (g) = PER
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What is a better source of protein, plant or animal based feed?
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animal based; has more amino acid
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What is BV/ Biological value?
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a direct measure of the proportion of feed protein that can be used by the animal for synthesizing body tissues
an indirect measure of the blend of essential amino acids in the feedBV = n intake - (fecal N + urine N) / N intake - fecal N
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What is the amino acid profile of an ideal protein patterned after?
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...
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What is an ideal protein?
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provides essential amino acids in the correct proportion so that tissue growth is maximized
is species specific
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What is a rate limiting essential amino acid?
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...
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What do rumen microbes do?
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provide a large proportion of the host animal's energy requirements by transforming dietary CHO to VFA's.
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What does the efficiency of microbial growth depend on?
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...
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What are two sources of metabolizable protein?
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bypass/ undegraded protein and microbial protein
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Exam 1 Flashcards