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85 Cards in this Set
- Front
- Back
Protein is the only macro-nutrient that contains ____.
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Nitrogen
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The basic structure of the amino acid molecule contains:
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one carboxyl group and one amino group
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Protein is the basic structural material from which all:
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body tissues are formed
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Protein is essential for:
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growth and development
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Most of the bodies ____ and ____ are basically protein in composition.
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enzymes and hormones
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Essential amino acid:
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needed by the animal, but cannot be synthesized by the animal, therefore must be provided by the diet
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Non-essential amino acid:
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needed by the animal and can be formed by the animal.
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All amino acids are nutritionally essential. T or F?
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False
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Biologically all amino acids are essential. T or F?
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True
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Examples of essential amino acids:
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Leucine, tryptophan, methionine, arginine, isoleucine
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Examples of non-essential amino acids:
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glycine, cysteine, alanine, aspartic acid, proline
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Limiting essential amino acid:
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present in the protein in the least amount in relation to the animal's need for that particular amino acid.
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Limiting amino acid determines:
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quality of protein
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Biological value of protein:
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percentage of the digestible protein of a feed that is usable as protein by the animal
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Biological value of protein depends on:
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limiting amino acid present in relation to other essential amino acids
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protein that has a desirable balance of essential amino acids is considered:
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of high biological value, high quality
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Protein digestion in monogastrics:
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whole proteins not absorbed, digestive enzymes break peptide bonds, secreted as inactive pre-enzymes (zymogen).
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Monogastric protein digestion is initiated in the:
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stomach
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Zymogens are stimulated by one hormone:
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CCK, secreted by pancreas
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Trypsinogen
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if inhibited no digestion or activation of zymogens can occur.
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Trypsinogen is inhibited by:
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heat
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Proteins are broken down to:
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tripeptides, dipeptides, free amino acids
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Examples of zymogens:
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trypsinogen (trypsin), chymotrypsinogen (chymotrypsin), procarboxypeptidase (carboxypeptidase)
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Amino acids diffuse across the:
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basolateral membrane
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The liver's role in protein transport:
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breaks down amino acids, synthesizes non-essential amino acids
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In ruminants, why does the quality of amino acids for absorption not reflect the quality of what is fed?
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Because of microbial breakdown to microbial proteins
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Typically microbial proteins are _____ in quality
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better
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RDP
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Rumen Digradable Protein - keeps the microbes happy
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RUP
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Rumen Undegradable Protein -escapes rumen fermentation, enters small intestine unaltered
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NPN
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non-protein nitrogen - not a true protein, provides a source of nitrogen for microbial protein synthesis
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NPN is favored because:
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it is cheap
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Microbial protein is not sufficient during:
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rapid growth and high production
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ADIN
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Acid Detergent Insoluble Protein - amount of protein that is insoluble. Not degraded by ruminant microbes
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High levels of ADIN indicate:
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poor quality of protein
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Metabolizable Protein
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net quality of protein - summation of digested feed and microbial protein minus nucleic acid
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MFN
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Metabolic Fecal Nitrogen - amount of protein that does not result directly from undigested feed protein or microbial protein.
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Sources of MFN
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enzymes and intestinal epithelial cells - comes from dead or endogenous forms
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Factors affecting ruminal degradation:
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rate of passage, solubility in water, heat treatment, N and S availability, energy availability
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Microbes break down dietary protein to:
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amino acids, NH3, VFA's and CO2
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Factors limiting microbial protein synthesis in rumen:
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amount of energy, available nitrogen, available carbohydrates
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What is protein converted to in the liver?
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urea (not toxic), NH3 is toxic
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Efficiency of the rumen is dependent upon:
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availability of dietary nitrogen
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Feedstuffs with biologically active proteins:
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Milk, collostrum, whey protein, plasma, fish meal (bone meal), yeast,
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Why is the length of biological proteins important?
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anything longer than 4 does not cross over, the shorter the proteins are the greater their health benefits are
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Transamination:
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amino group transferred to glutamate, which is deaminated, releasing ammounium. Intermediate for NH3 removal
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Deamination:
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ammonium is released directly from amino acids
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Steps in Urea synthesis:
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1. Formation of carbamoyl phosphate 2. Formation of citrulline 3. Formation of arginosuccinate 4. formation of arginine 5. formation of urea
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The first two enzymatic reactions happen in the:
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mitochondria
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The second two steps of urea synthesis happen in:
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cytosol
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Excess Aceyl CoA will be used for:
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ketogenesis
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Regulatory step in branched-chain amino acid synthesis
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BCKA dehydrogenase
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Three compounds that serve as carriers of the C units:
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Biotin, SAM (S-adenosyl-methionine), THF (tetrahydrofolate)
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Biotin
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transfers carboxyl groups and is used by three major carboxylases
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SAM
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transfers methyl group and is used in methylation reactions
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THF
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transfers C atoms at all other oxidation states
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NEAA cysteine is synthesized from:
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essential amino acid methionine
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NEAA tyrosine is synthesized from:
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essential amino acid phenylaline
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Interorgan synthesis of Arginine: carbamyol phosphate synthetase-1 adn ornithine transcarbamoylase occur in the:
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small intestine
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Interorgan synthesis of Arginine: argininsuccinate synthetase and arginino lyase occur in the:
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kidney
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Dried skimmed milk is used for protein, but not energy, why?
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because the fat has been removed
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Fish Meal:
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fish or fish by-product that has been dried and ground into meal. Good quality protein
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Soybean Meal:
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excellent source of protein, the most widely used protein feed in the US
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Cottonseed Meal:
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excellent source of protein for ruminants. May kill growing swine if included in rations higher than 9%, because pf gossipol.
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Characteristics of energy feeds:
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consists primarily of grains, contain less than 20% CF and CP, high energy, low in fiber
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Corn grains:
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most widely used energy feed, excellent source of energy, excels in lbs of TDN, low in methionine, lysine and tryptophan, Low in Ca and B12
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Limiting factors of corn grains:
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low in lysine and tryptophan and Ca and B12
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Corn used for:
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fuel production, food production, exports
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Color of corn comes from
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carotene
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Grains sorghum:
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fed mostly in semi-arid western regions, can replace 50% of corn ration, draught and heat tolerant, fed flaked or rolled
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Citrus Pulp
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fed mainly to dairy and beef cattle, high in fiber, high in Ca and K
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Animal Fats
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good source of energy, used primarily for: reducing dustiness, improve color, improve texture, improve palatability (high saturated fatty acid)
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Legume
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nitrogen fixing nodules, therefore can meet their own nitrogen needs
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nonlegume
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no capacity to harbor nitrifying bacteria, must depend on outside sources for N supply
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Annual
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crop that must be propagated from seed every year
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Perennial
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does not have to be seeded each year, will reestablish itself
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Summer crops
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starts growing at the onset of warm temps, continue growing until frost
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winter crops
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starts active growth in the fall and remain alive during winter. Little if any growth during summer.
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Temporary pasture
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seeded on freshly cultivated soil for use through only one grazing season
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permanent pasture
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once established, remains for a period of years
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Young plants are much richer in:
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protein
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Alfalfa
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perennial summer legume, very palatable, high L/S ratio, higher biomass, can cause bloat in ruminants
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Bermudagrass
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perennial summer grass, young grass makes excellent pasture, Florida grass, should be interseeded with legumes
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Coastal Bermudagrass
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hybrid bermudagrass, developed in Ga, will not survive winter above southern coastal states, varies in nutritive value, but drought resistant and high carrying capacity
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Bahiagrass
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perennial grass, grown througout South, Florida grass, will not survive winter above lower coastal plain, produces viable seed, must be fertilized with N, can be hard to control
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Why is pasture not widely used for dairy operations?
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price of land too high to justify pasture, control of off-flavors too great a problem, quality of pasture varies too much.
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