Know why feedstuffs of animal origin are higher in protein quality than those of plant origin.

- the amino acid profiles of the animal-based protein feedstuffs more closely match the amino acid profiles required by the animal

Definition of protein quality

- the ability of the food protein to meet the animals req’s for amino acids.

how protein quality is determined

- Animal trials 

1) Biological Value: higher BV= higher Quality

2) Nitrogen Balance: B = NI - (UN + FN)

3) Net Protein Utilization (NPU)- require whole body nitrogen [euthanize organism and grind up and homogenized- mostly rats]

4) Protein Efficiency Ratio (PER)- weigh orgn.

5) Net Protein Ratio (NPR)- require whole body nitrogen

6) Slope-Ratio Assay)

- Wet chemistry

1) Chemical Score: contains these AA but don’t know amount absorbed

2) ESSENTIAL AMINO ACID INDEX (EAAI): all 10 essential AAs are used here= better)

first-limiting amino acid

- Of essential AA in dietary protein, the AA in the least amount in relation to the animal’s need is first-limiting.

protein synthesis

- Molecular Blueprints required and found within the genes of chromosomes. 

- Chromosomal DNA contains the coded sequences for the proteins

- STEP 1: (transcription): Chromosomal DNA “TRANSCRIBES” the protein code onto mRNA.

- STEP 2: (translation)

-initiation: mRNA leaves the nucleus and attaches itself to a ribosome.

-elongation: mRNA is decoded; tRNA carries the amino acids and inserts them.

              -termination : Final amino acid is placed, the protein is released from the ribosome.

levels of protein structure and the bonds responsible for the structure

a) Primary (Peptide Bonds)

b) Secondary

                       1) alpha helixes (Hydrogen Bonds)

                       2) beta sheets (Hydrogen Bonds)

                       3)turns

c) Tertiary; Bonding: Hydrogen, Disulfide, Salt Linkages

d) Quaternary (polypeptide); Bonding: Similar to Tertiary

Be able to calculate the Crude Protein Equivalents of a NPN compound

Example from Exam #3:

A dairy cow requiring 6 lbs of crude protein is consuming 50 lbs of a diet containing 1.0% urea. How many lbs of urea is she consuming, how many lbs of CPE is she consuming, and what percent of her protein requirement would be met by the urea?

            Pounds of urea: 50 lbs of diet X 0.01 urea = 0.5 lbs

            Pounds of CPE: 0.5 lbs urea X 2.81 = 1.405

            % Protein Req. Met: 1.405 lbs CPE/ 6 lbs CP req. = 0.2342= 23.42%

ANABOLISM

the set of metabolic pathways that construct molecules from smaller units.

CATABOLISM

The metabolic breakdown of complex molecules into simpler ones, often resulting in a release of energy.

Provide an example of an essential amino acid.

                    PVT TIM HALL:

phenylalanine                               isoleucine 

valine                                           methionine

threonine                                      histidine

tryptophan                                    leucine

arginine                                        lysine

Why do ruminant nutritionists

have less concern about protein quality of the diet?

-        Ruminant animals are insulated against essential amino acid and most vitamin deficiencies because these compounds are synthesized by symbiotic microbial populations in the rumen and subsequently presented for hydrolytic digestion in the gastric-intestinal region.

-        Once microbial protein passes from the rumen to the gastric-intestinal region, it is hydrolyzed to the individual amino acids which are absorbed for use at the tissue level.

-        Therefore, ruminants can survive on a protein-free diet as long as the diet contains a form of nitrogen to yield ammonia under anaerobic fermentation.

 Be able to provide an example of a sulfur containing amino acid, a basic, acidic, aromatic and branched chain amino acid.

- Basic (+): Lysine, Arginine, Histidine

- Acidic (-): Glutamic Acid, Aspartic Acid

- Aromatic: Tyrosine, Phenylalanine, Tryptophan

  - Branched: Valine, Leucine, Isoleucine

- Sulphur: Methionine, Cysteine

- Other Amino Acids of Proteins: Threonine, Alanine, Proline, Glutamine, Asparagine, Glycine, Serine

What is usually the first limiting

amino acid in a swine diet?

LYSINE

What amino acid is usually first limiting in grains?

LYSINE

Why is gossypol a problem and in what feed would I find it?

-COTTONSEED MEAL

 -Contains phytotoxin “gossypol” must “degossypolize” to safely feed

 -Signs of gossypol toxicity:

- pneumonia-like symptoms

- liver damadge and abdominal edema

- fetal death & abortions

- male sterility (dec. spermatogenesis)

Know where the bonds where the enzymes involved in protein digestion cleave.

TRYPSIN:

N-Met-Ser-Phe-Ala-Glu-Asp-Lys/-/Tyr-Leu-Phe-C

- trypsin makes smaller peptides, never releases free AA,  leaves either : lys, arg, histidine in C position

N-Met-Ser-Phe-Ala-Glu-Asp-Lys- C

- trypsin would not do anything here

N-Trp-Cys-Pro-His/-/Ile-Val-Arg/-/Phe-Met-Trp-C

- trypsin cleaves at basic to create three small peptides so leaves basic AA in C terminal position-->  body can absorb 3 or less AA peptides

Know where the bonds where the enzymes involved in protein digestion cleave.

Chymotrypsin:

N-Cys-Trp/-/Pro-His-Ile-Val-Arg-Phe/-/Met-Trp-C

- leaves aromatics in C terminal position so here it cleaves at

Be able to provide examples of

specific functions for amino acids.

Glycine: Purines, Glutathione, Glycocholic Acid (bile acid- lipid digestion)

SERINE: Purines, Pyrimidines

METHIONINE: Primary Methyl Donor- imp. for methylation rxns

CYSTEINE: cat (Taurine essential AA)

            - Precursor of TaurineàTaurocholic Acid

Tryptophan: Serotonin, Niacin

Tyrosine: Melanin, Epinephrine, Norepinephrine, T₃ & T₄

Why is protein turnover necessary?

- Protein is a dynamic tissue. It is constantly undergoing breakdown and synthesis.

- Restructuring (Muscle Tissue), Cell and Tissue Repair, Enzyme and Hormone Production, Antibodies, Remove Harmful Proteins (ie. Faulty Amino Acid Sequence), Replace Blood Clotting Proteins, Replace Transport Proteins (ie. Hemoglobin)

What is FSR?

-Fractional Synthesis Rates (FSR) are determined to measure protein turnover

-FSR= percentage of the protein in an organ/tissue that is synthesized/day

-Liver  (87%), Kidney - (48%), Heart - (17%), Brain - (17%), Muscle - (13%) (varies greatly), S.I. Mucosa - (136%)

-25-33% of maintenance energy is expended just for protein turnover.

1)PROTEIN Digestion

(non-ruminants): 

- Begins in the stomach, however gastric digestion is dispensable

- Enzymes involved:                       

         - 1)Pepsinogen is converted to PEPSIN by HCl

                  - It acts as an endopeptidase (works on peptide bonds within protein- aka makes smaller peptides)

         - 2)Gelatinase liquifies gelatin

         - 3)Rennin curdles the milk protein casein to facilitate its digestion-changes conformation most of these are secreted in an inactive form

2)PROTEIN Digestion

(non-ruminants): 

- Majority of protein digestion takes place within the small intestine

- Several enzymes are involved and originate from:

                   1) Pancreas

                   2) The small intestinal cells (Brush Border- ex: sucrase, lactase, maltase for Carbs)

                   3) Intracellular enzymes (complete digestion) 

3)PROTEIN Digestion

(non-ruminants): 

The enzyme trypsinogen is activated by the action of an enteropeptidase called Enterokinase and the result is TRYPSIN which is AUTOCATALYTIC (once you have trypsin it can activate other pancreatic enzymes) 

4)PROTEIN Digestion

(non-ruminants): 

-    Pancreatic Enzymes: released as Proenzymes, meaning they are inactive (CCK stimulates pancreas)

            - Trypsin- cleaves bonds in which the BASIC AMINO ACIDS donate the carboxyl group: trypsin makes smaller peptides, never releases free AA,  leaves either: lys, arg, histidine in C position

            - Chymotrypsin- cleaves bonds in which the AROMATIC AMINO ACIDS donate the carboxyl groups;  leaves aromatics in C terminal position

            - Elastase- broad concerning amino acids but is specific for elastin fibers

            - Carboxypeptidase A- Follows the action of Chymotrypsin and cleaves the aromatic amino acids from the C-terminal end

            - Carboxypeptidase B- Follows the action of trypsin and cleaves lysine and arginine from the C-terminal end

5)PROTEIN Digestion

(non-ruminants): 

Brush Border Enzymes:

1)             Aminopeptidases- There are many that cleave amino acids from the N-terminal end

2)             Dipeptidases- There are many that cleave dipeptides

3)             Tripeptidases- There are many that cleave tripeptides

- Several intracellular peptidases that cleave dipeptides and tripeptides that are absorbed

1) PROTEIN Digestion

(ruminants):

- Protein (amino acids) found within the small intestine of the ruminant are from two sources generally:  

   1) RUP (rumen un-degradable protein), By-pass, Escape

   2) Microbial 

2) PROTEIN Digestion

(ruminants):

BY-PASS:

           -Dietary protein NOT UTILIZED by the rumen microbes.

     -Referred to as RUP: is digested and absorbed similar to a non-ruminant in the true stomach and SI of the animal—>animal protein have more RUP than plant protein

3) PROTEIN Digestion

(ruminants):

MICROBIAL:

        A) The microbes themselves- Excellent source of protein as they pass from the rumen to the stomach and SI

        B) Microbial Protein- Proteins actually made by the microbes which pass from the rumen to the stomach and SI.

                        C) Urea Recycling- Important source of nitrogen for microbes

Why do legumes such as soybean

meal have to be heat processed?

-   Heating inactivates growth inhibitors (ie. Trypsin inhibitor) = needs to be heated b/c : To denature the trypsin inhibitor that prevents protein from being absorbed

- Heating inactivates urease enzyme

- alot of urease activity= haven’t heated enough

- zero activity= overheated 

What are RUP and RDP?

-       RUP (rumen un-degradable protein)

-       RDP (Rumen degradable protein)

What is the importance of gluconeogenesis?

-making glucose from carbon chains present in body (mostly in the liver)

-primary gluconeogenic substance from ruminant: propionate

         -non-ruminant: gluconeogenic AA’s

                         -other possibilities: lactic acid, glycerol backbone fatty acid digestion

                  -Besides Gluconeogenesis being the reverse of Glycolysis and requiring significant energy input, what is one other step that differs?

                            - Must use shunt (oxoacetate/malate) to get from pyruvate to PEP

   -The step between Fructose 1,6 – Biphosphate and Fructose 6- Phosphate in Glycolysis and Gluconeogenesis are catalyzed by different enzymes: 

                                     -Glycolysis - Phosphofructokinase

                                     -Gluconeogenesis - Fructose 1, 6 Bisphosphatase 

Be able to name the major nitrogenous excretory product in various animals.

-       NH₃ (aquatic animals)

-       uric acid (birds/reptiles)

-       urea (mammals except Dalmation: uric acid)

-       Others: Amino Acids, Allantoin, Creatinine protein, Amino Sugars, vit 

Know a function of protein within the body.

-Structural Components, Enzymes, Transporting Agents, Hormones, Osmotic Regulators, Buffers, Antibodies, Blood clotting-(vit. K), Visual Pigments (vit. A), Connective tissue

-Many Others (peptides, small proteins that appear to have biologic activity)

Know the importance of the urea cycle, where it takes place, energy expended, and the important amino acid that serves as a collection point.

-       Importance: nitrogen excretion

-       Where: the liver contains a system of carrier molecules and enzymes which quickly converts the ammonia (and carbon dioxide) into urea where the kidney removes it

-       Energy expended: 3 ATPs/Urea molecule

-       Important AA that serves as a collection point: GLUTAMATE

1)             How is forage quality measured?

- Is defined / indicated by the production rate of a ‘producing’ animal (growth or milk) when the forage is fed alone and free-choice (ad libitum)


- Forage Testing Programs:

            Visual- American Forage Grasslands Council (AFGC)

                              - leafy, green, good stem, smell, maturity

                              - species, estimate nutrient content from species

            Chemical analysis and use of prediction equations

-       near infrared reflectance spectroscopy (NIRs)

2)             What are the two main factors that affect forage quality?

-Voluntary intake

Nutritive Value: TDN, DE, CP, etc

 3)             What can influence an animal's voluntary intake?

-       Ration factors: Processing (grinding and pelleting), Palatability (feedstuff acceptance due to taste, odor, texture, etc.), Diet components (complementary feeds and TMRs)

-       Animal factors: Gut capacity, passage rate, Body Weight, age, sex, hierarchy, Physiological state/ Production level, Health, Condition score, Individual preference, appetite

-       Management Factors: Stocking rate, Feed bunk deisgn, Forage treatments applied, water intake, cow comfort

            -   Climatic Factors: Temperature (Cold stimulates appetite/Heat depresses), Humidity 

4)             What can influence a forage’s nutrient content?

- Irrigation, Fertilizer, Maturity of forage, Pre-Harvest handling, Post-harvest handling, Species of forage, Chemical & botanical composition (leaf: stem ratio, Antinutritive factors e.g. toxins, mold etc. and Protein content, digestibility)

5) Be able to calculate voluntary TDN and Protein intakes from the data supplied.

If voluntary hay intake = 12.3 kg/day (as-fed)

And if hay DM =90% & hay TDN =46% (DM basis)

What is the daily TDN intake from the hay?

Solution:    - DM intake = 0.9 x 12.3 = 11.07 kg/day

                   - TDN intake = 0.46 x 11.07 = 5.09

       - Hence TDNI = 12.3 x .9 x .46= 5.09 kg of TDN

6)  Be able to describe the various types of forages 

HAY

- Product of sun-curing (wilting) cut grass in the field for (2-4) days and then stored under dry conditions

- A Dry forage (NRC #1) that contain 70 – 92% DM

- Aim = Decrease moisture to a level that inhibits microbial activity

- Drying causes carotene losses, but increases Vit. D

7)  Be able to describe the various types of forages 

STRAW

-example of a crop residue: (NRC #1: 88-92% DM)

- contains high lignin, low digestibility, and low protein

- mature stems that are by – products of grain or food crops

- left after grain harvest, used for bedding

8)  Be able to describe the various types of forages 

- (NRC classification #3); Contains 20-40% DM

- Product of anaerobic storage of high moisture forage

- Storage process= fermentation or ensiling

- Form bulk of dairy cow diets especially during winter

- Stored in silos (towers, trenches, bunkers, plastic bags)

- Oxygen-exclusion is crucial for ideal type of fermentation

What is a premix when discussing vitamins and minerals for animals?

- Therefore, vitamins are supplemented to animal diets to avoid deficiencies and to:

–      maximize growth, minimize production costs, maximize reproductive potential and enhance health and well-being of the animals

•       Factors which can affect vitamin premix potency:

                        - Particle size, pH, Carriers, Vitamin/Mineral Premixes

      - Environmental conditions: Temperature, Storage time, Humidity, Light

•       ** Use Vitamins ASAP

What is Beta Carotene?

-       The most potent carotenoid is β -Carotene. 

-       This carotenoid is converted in liver and intestinal cells to VITAMIN A. 

•       However, the conversion is poor.

-       Carotenoids: Prevent photodynamic damage from oxygen molecules

1) Be able to explain the function of vitamin A in vision.

–      Rhodopsin is made from the protein OPSIN and VIT A in the form of RETINAL.

–      Chemistry of sight: retinol in Blood à Retinol (converted to RETINAL in retina of eye)à Retinal (visual yellow)à Opsin protein converts it to RHODOPSIN in rods of retinaà bleachingà nerve impulse to brain à sight! 

2) Be able to explain the function of vitamin A in vision.

-       Vit. A def: leading cause of blindness àretinol corneal ulceration.

Within RETINA of the eye there are:

–      Rod Cells, not color sensitive but light sensitive. Cells contain millions of molecules of RHODOPSIN.

–      Cone Cells, color sensitive and require lots of light.

–      RHODOPSIN (visual purple) is a pigment in the rod cells that absorbs photons of light

–      Must have a constant supply of retinal to replace what is lost in the previous cycle.

What is keratin? 

- a family of fibrous structural proteins. Keratin is the key structural material making up the outer layer of human skin. It is also the key structural component of hair and nails.

What is the plant provitamin that gives rise to vitamin D?

Ergosterol

What is the animal provitamin that gives rise to vitamin D? 

7-dehydrocholesterol

How are the vitamin D provitamins converted to the active form of vitamin D3?

-       Vitamin D₃, the naturally occurring form of the vitamin in animals, is produced from the provitamin, 7-dehydrocholesterol (produced from cholesterol metabolism), found in the skin under the stimulation of ultraviolet (UV) irradiation or UV light.

•       Vitamin D3 requires hydroxylation by the liver and the kidney to be fully active.

•       D3: Synthesis from cholesterol in the skin, small intestinal cells and liver.

How are the vitamin D provitamins converted to the active form of vitamin D2?

What form of vitamin D can the chicken not use?

-       Ergocalciferol: referred to as Vitamin D₂, not well utilized by birds. 

•       Transport proteins do not recognize the different side chain.

What 3 tissues in the animal does vitamin D exert its action on to maintain blood calcium?

KIDNEY, BONES, SMALL INTESTINES

RICKETS

A VITAMIN D deficiency causes this skeletal condition in young animals or people

OSTEOPOROSIS

A vitamin D deficiency caused by a loss of total bone mass with normal ratio of mineral to matrix in older animals or people. 

OSTEOMALACIA

A loss of bone mineral per unit of bone matrix in older animals or people. 

 What is the most potent tocopherol for animals?

D-alpha- tocopherol 

What are the two major lines of defense in the animal cell that protect it from peroxide damage?

- (mitochondria, lysosomes, etc) and membranes.

What trace mineral is associated with vitamin E and its protective ability against peroxides?

SELENIUM

 What is exudative diathesis and encephalomalacia?

BOTH caused by Vit. E deficiency:

•       Exudative Diathesis- Edema due to leaky cells

•       Encephalomalacia- Hemorrhages and Edema in the Brain. 

•       Referred to as “CRAZY CHICK DISEASE”

What is menadione, menaquinone, and phylloquinone?

Several compounds have vitamin K activity and are classified as follows:

–      PHYLLOQUINONES (K1) found in plants. Most common form.

–      MENAQUINONES (K2) found in fish oils and meat and synthesized by intestinal bacteria.

–      MENADIONE (K3) synthetic form.  It’s 3.3 times more potent than K1 or K2.

What is dicoumarin?

- Certain feedstuffs contain ANTICOAGULANTS such as moldy sweetclover which contains DICOUMARIN.

•       (opposite coagulation involved in Vit. K)

What is collagen and what vitamin is associated with its

synthesis?

-       Collagen: a group of naturally occurring proteins found in animals, especially in the flesh and connective tissues of vertebrates. It is the main component of connective tissue, and is the most abundant protein in mammals.

•       Vitamin C acts as a coenzyme for the enzyme stabilizing the Ferrous Iron.

What animals require vitamin C in the diet?

•       Animals that require Vitamin C must have a constant daily supply

•       Indian Fruit Bat, Guinea Pig, Great Apes, and HUMANS

What are hydroxyproline and hydroxylysine and what is their importance with reference to collagen formation?

Collagen Formation:

•       Requires the hydroxylation of PROLINE and LYSINE

•       The enzyme that adds the OH to proline and lysine requires FERROUS IRON (Fe⁺⁺) and cannot use FERRIC IRON (Fe⁺⁺⁺). 

•       Vitamin C acts as a coenzyme for the enzyme stabilizing the Ferrous Iron.

 Why do ruminants usually not have B vitamins added into their diet?

- Microbes: have enzyme required for synthesis

            - Non-ruminants do synthesize B-complex in the lower GIT, but not well absorbed.  Most escapes in the fecesàCoprophagy- consume own feces b/c of vitamin content

Where in the plant and the animal will you find the highest concentration of the B vitamins?

most ACTIVE tissue

VITAMIN A deficiency signs:

ü  Night Blindness (lack of rhodopsin)

ü  Copius Lacrimation

ü  Insufficient Mucus Production Leads to:

ü  Xerophthalmia (dry eye, a leading cause of blindness)

ü  Follicular Hyperkeratosis (keratin accumulation around hair follicles)

ü  Epithelial Keratinization

ü  Dermatitis

ü   Poor growth and differentiation of:

ü  Epithelial, nervous, bone, and other tissues

VITAMIN D deficiency signs:

-       Rickets, Osteomalaacia, Osteoperosis

-       VIt. D works in concert with estrogen to prevent bone loss

VITAMIN E deficiency signs:

•       Exudative Diathesis- Edema due to leaky cells

•       Encephalomalacia- Hemorrhages and Edema in the Brain.  Referred to as “CRAZY CHICK DISEASE”

•       Muscular Dystrophy - Neuromuscular disorder

a)     Hereditary b) Nutritional (lack of Vitamin E, can be cured)

•       Deficiency signs of Vitamin E can lead to:

–      Reproductive Failure (apparently not so in man)

–      Muscle Degeneration (Nutritional Muscular Dystrophy)

–      Membrane Damage

–      Kidney Degeneration

–      Necrosis of the Liver

VITAMIN K deficiency signs:

–      Increased Blood Clotting Time

–      Internal Hemorrhages

–      Newborns at greatest risk

•       Deficiency however is rare

VITAMIN C deficiency signs:

•       Deficiency signs and symptoms of scurvy include:

–      Loss of teeth, Loss of hair, Bleeding gums, Skin Lesions, Loss of fingernails

–      Hemorrhages throughout the body

THIAMIN (B1) deficiency signs: 

            - cardiovascular, neurological

–      Polyneuritis- CNS disorder of chicks

–      Polioencephalomalacia- Cerebrocortical necrosis in cattle. Primarily due to converting to concentrate too rapidly; can effect pH aka microbial population.

–      Classic Sign: Beriberi- Muscular weakness and trembling in humans. Mg and Mn are required for all functions of thiamin.

•       Emperor’s Disease- Asia, eat rice but the emperors eat polished rice which has the seed coat removed

RIBOFLAVIN (B2) deficiency signs: 

-       Nervous System

-       Curled toe paralysis- enlargement of the myelin sheath of sciatic nerve

-       Ariboflavinosis- inflammation of the tongue and mouth

NIACIN (B3) deficiency signs: 

- Nervous System, Skin

- Classic Sign – Pellagra (Diarrhea, Dermatitis, Dememntia, Death)

                                    - characterized by scaly sores, mucosal changes and mental signs. 

PANTOTHENIC ACID (B5) deficiency signs: 

-       Nervous System? b/c myelin is a fatty tissue= synthesized from acetate aka acetyl coA

-       Nerve impulses carried through insulated nerve fibers. Nerve fibers are surrounded by MYELIN.

-       Myelin is synthesized from cholesterol which is synthesized from ACETATE.

-       Nerve demyelination- causes Goose- Stepping in Swine

•       Pig- myelin sheath issues and signals don’t’ send to leg

-       Nausea, Headaches, Fatigue

BIOTIN (H) deficiency signs: 

-       Skin? Layer of fat under skin and due to its involvement with fatty acid synthesis

-       Dermatitis, Nausea, Muscle pain and weakness

-       Lack of the enzyme Biotinidase

-       Natural ANTIVITAMIN called AVIDIN.

•       Avidin binds biotin and inhibits its absorption.

•       Avidin is found in raw egg whites

PYRIDOXINE (B6) deficiency signs: 

-       Nervous System

•       Neuro-transmitters affected

•       Symptoms: apprehension, irritability, twitching, tremors, spasms etc.

•       Can also be kidney stones b/c inability to catabolize amino acids properly 

CYANOCOBALAMIN (B12) deficiency signs: 

                        - Anorexia

-       Pernicious Anemia: in ruminants can get a B12 deficiency if cobalt is lacking

-       It can also be necessary for propionate metabolism

-       Animals and humans: limit diet of animal tissue at risk for deficiency 

FOLATE deficiency signs: 

-       Macrocytic Anemia (large red blood cells)

•       Red blood cells should divide but if not sufficient DNA= don’t divide

•       Large RBC’s don’t move through capillary beds

•       DNA synthesis interrupted, cells cannot divide

•       Remain immature formà MEGABLASTS (which form macrocytes) 

Be able to identify the key function for each of the B-complex vitamins.

THIAMIN: Decarboxylation Reactions

RIBOFLAVIN: Oxidation-Reduction Reactions (FAD, FMN)

NIACIN: Oxidation-Reduction Reactions (NAD, NADP)

PANTOTHENIC ACID: Coenzyme A

BIOTIN: Carboxylation Reactions

PYRIDOXINE (B6): Amino Acid Reactions and Protein Synthesis

CYANOCOBALAMIN (B12): Normal Red Blood Cell Formation (associated with Folate)

FOLATE: Single Carbon Metabolism (DNA, RNA, Amino Acids)

What amino acid can be converted in the animal cell into niacin?

TRYPTOPHAN 

 What vitamin is associated with coenzyme A?

PANTOTHENIC ACID (B5)

What vitamin is usually associated with avidin?

BIOTIN (H)

                 What mineral is associated with B₁₂?

COBALT

Know and be able to explain B₁₂ absorption

•       Initially B12 is released from food within the stomach (However, if not bound it is digested)à must be bound to R-protein (produced in salivary glands) for further absorption b/c R-protein protects it from stomach acid

•       R-protein -B12 complex moves to small intestines where trypsin removes the R-protein

•       Within the small intestines B12 is bound now to INTRINSIC FACTOR (produced by the parietal cells in stomach) which facilitates B12 absorption in the ileum

Why is choline necessary?

-       Necessary component of Acetylcholine and Lecithin (Phosphatidylcholine) 

a.     What is a diet?

-A mix of feeds which have:

            - Meets all nutrient requirements

                        - Meets any and all restrictions

                        - Must be able to consume an adequate quantity

                        - Nutrient concentrations expressed as:

–      % (ie. 10% crude protein)

–       Amounts per kg 

b.     What is a ration?

-Similar to a diet, but is the 24 hr allotment of feed given to an animal

-Like a diet it is a mixture of feeds which have:

•       Nutrients in proper amount (min/max) and proportion (balance).

•       Meets any and all restrictions

•       Must be able to consume an adequate quantity

•       Nutrient concentrations expressed as:

–      Amounts per day (ie. 650 g of crude protein/day)

c.     Know the steps involved in diet and ration formulation (there are 4 steps): 

1st two: 

1) Identify Animal: Weight, age, gender, species, production level, reproductive phase

2) Determine the animal’s nutrient requirements:

•       Req’s listed in several ways:

–      Could be by weight, gender, production level, reproductive phase or a combination of two or more

•       Req’s listed in one of two ways:

–       as nutrient concentration: (% OR amount/kg)

–       as daily nutrients per animal: (Amount/day)

•       Where are the animal’s nutrient requirements found?

–      Most common for food animals and others: NRC tables

c.     Know the steps involved in diet and ration formulation (there are 4 steps): 

3rd Step 

3) Selection of feedstuff-Criteria used:

–       Availability: Home grown or locally available

–       Suitability for animal being fed:

»      Forages are the base ingredient for ruminants and equine diets and rations

»      Grains are the base ingredient for non-ruminant (ie. swine and poultry) diets and rations

»      Restriction of certain feeds due to side effects or toxicity

–      Nutrient content:

»      If base feed is low in protein must choose a protein supplement to complement

»      Also must be sure feedstuff composition expressed in the same basis as nutrient requirement (ie. DM vs As-Fed; CP vs DP; TDN vs DE)

–       Cost per unit of nutrient

c.     Know the steps involved in diet and ration formulation (there are 4 steps): 

4th step

4) Balance the diet or ration:

•        Initial approach:

–      Determine nutrient concentration in diet

–      Determine daily requirement for ration

•        Determine fixed ingredients if any:

–      Could be small amounts (ie. Salt - 0.25%; TMP- 0.10%)

–      Could be large amounts (ie. 15% wheat bran; 40% corn silage)

•       Balance the variable ingredients 

d) Be able to balance a diet or ration using Algebraic Method or Simultaneous 

ON LAST HANDOUT/EXCERCISE

                                               Why is the calcium to phosphorus ratio in the diet important?

Absorption occurs in the duodenum and depends on the Ca:P ratio

-It is important in maintenance and in growing animals 

What causes nutritional secondary hyperparathyroidism?

- Phosphorous toxicity (possibly with excess P in relation to Ca)

What is phytate? 

-       Phytic acid is the principal storage form of phosphorus in many plant tissues, especially bran and seeds-à binds Ca, P, and other cations

What is the function of PTH and Calcitonin?

-       Important agents in Ca regulation:

-       PTH (parathyroid hormone): increases blood Ca++ by increasing:

o   bone mobilization, resorption from proximal kidney nephrons, absorption from the GIT

-       Calcitonin: turns on osteoblasts in BONES

o   Decreases blood Ca

o   Increases Ca++ deposits in bone 

What 3 minerals are usually associated with maintaining osmotic pressure in animals?

Potassium (with Na, Cl, and bicarbonate ions) 

Explain the regulation of sodium in the body.

-       Plasma sodium is controlled by ALDOSTERONE

-       Plasma Sodium drops à Anterior Pituitary releases ACTH à ACTH stimulates the Adrenal Cortex à Aldosterone is released à Target tissue: kidney

-       Important to maintain plasma sodium levels because of blood pressure regulation, Acid/Base balance, etc. 

Does plant tissue contain higher concentrations of sodium or potassium?

- Low in sodium, High in potassium

Does animal tissue contain higher concentrations of sodium or potassium?

- Higher in potassium, High in sodium also

 Is the cell concentration of potassium usually higher or lower than sodium?

-       HIGHER

What is achlorhydria?

- Caused by chlorine deficiency

- Insufficient HCl à wont be able to act as a bacteriostat. 

What is grass tetany?

-Caused by magnesium deficiency

            -Wheat pasture poisoning

            -Also called grass staggers

            -Occurs in ruminants grazing winter pastures (wheat and rye) and also new growth of grasses in the spring: typically young weaning calves.

What are the signs of a magnesium deficiency in the ruminant?

-Muscle tetany, head retraction, staggering, convulsion, heightened sensitivity to noise/touch

            -Legs go into tetany (contraction) – fatal in a short time 

What is the only known function of cobalt in animals?

Component of Vitamin B12

What are the thyroid hormones and their functions?

-       T3 (Triiodothyronine) and T4 (Thyroxine) [Iodine is a component of both]:

                  -Increases metabolic rate

                  -Increases fat and carbohydrate utilization

                  -Increases protein synthesis

                  -Increases nerve & bone formation and growth rate

Why does the thyroid enlarge with either an iodine deficiency or toxicity?

ü  Deficiency: (Hypothyroidism) àResults in a goiter.

–      Iodine deficiency causes anterior pituitary hypersecretion which causes thyroid enlargement Goitrogens (e.g. in rape, soya, kale, turnips) interfere with thyroxine (T4) synthesis and also cause hypothyroidism

ü  Toxicity: (Hyperthyroidism)

•       Excess Iodine causes excess thyroxine (T4) which inhibits TSH

•       Increased heart rate and BMR rate

•       Nervousness, excitability

•       Goiter

–      Q:   What causes a goiter?

–      A:   Iodine is the principal component of thyroxine, the thyroid gland's hormone. If there is not enough iodine in the diet, there is insufficient thyroxine, and the pituitary gland responds by releasing more thyroid-stimulating hormone. This causes enlargement of the thyroid gland.

–      However, a goiter may also be caused by overactivity of the pituitary gland or by overactivity of the thyroid gland itself (hyperthyroidism).

What enzyme is usually associated with zinc?

ü  Cofactor for over 200 enzymes and also proteins-

–      Carbonic anhydrase: necessary for acid-base balance in the blood

–      Retinal dehydrogenase: visual pigment

–      Superoxide dismutase: detoxification of peroxides

–      Retinol-binding protein: Vitamin A transport

–      Lactate dehydrogenase

–      Pancreatic carboxypeptidase

What is parakeratosis?

-Severe dermatitis-à CHUNKS falling off

-Caused by ZINC deficiency 

Know how iron is absorbed, transported, deposited and stored.

–      Heme Iron is absorbed intact into the small intestinal cell

–      Non-heme iron is absorbed dependent upon form; Fe⁺⁺ more available than ferric (Fe⁺⁺⁺)àAbsorption occurs in ferrous (Fe⁺⁺) state

–      Acidic conditions increase absorption: Vit. C (ascorbic acid) coverts Fe⁺⁺⁺ to Fe⁺⁺

–      Within intestinal cells, Fe⁺⁺ combines with a protein (apoferritin) and forms ferritin (short term storage form of Fe in the small intestine)- if the body needs iron ferritin will give up Fe++ to blood

–      Feric oxide = rust on salt blocks

–      In the intestinal cells, Ceruloplasmin (enzyme containing Cu) converts Fe⁺⁺ to Fe⁺⁺⁺  

–      Fe+++ is transported as transferrin in the blood

–      Iron is also stored in a less available form as hemosiderin in the liver, spleen, and bone marrow. Blood loss- major cause of loss of iron in short amount of time

What is achromotrichia?

Hair depigmentation due to copper deficiency 

Are animal or plant sources of selenium more bioavailable to animals?

PLANT

Raw rock phosphate sources are usually contaminated with what trace mineral?

FLUORIDE

What mineral is usually associated with white muscle disease in cattle?

Selenium deficiency 

What mineral is associated with the taste mechanism?

ZINC

Chromium deficiency signs: 

VERY RARE= impaired glucose tolerance and elevated blood cholesterol 

Cobalt deficiency signs: 

Reduced appetite and growth, emaciation, anemia due to B12 deficiency 

Copper deficiency signs: 

Dental decay 

Iron deficiency signs: 

Anemia (Microcytic and Hypochromic): Low Hematocrit, Low Hemoglobin

                        - Nursing piglets most susceptible b/c housed indoors and cannot get sufficient iron from dirt like in the wild       

Manganese deficiency signs: 

RARE, Perosis (slipped tendon in chicks), Crooked Calf (abnormal bone/joint growth, enlarged joints, lameness, bow legs), Reproductive problems (delayed estrus, abortion)

Molybdenum deficiency signs: 

VERY RARE= deficiency caused no adverse effects in chicks, But tungstate addition (binds Mo) reduced growth and xanthine oxidation

Selenium deficiency signs: 

Likely if soil content is low= white muscle disease (cardian and muscle streaking, muscle weakness, pain, difficult movement), Exudative diathesis, Unthriftiness (weight loss and death), Liver necrosis 

Zinc deficiency signs: 

Decreased appetite, Impaired Reproduction, Decreased Bone Growth and Feathering (swollen hocks in poultry), Parakeratosis (severe dermatitis), Impaired immune function and wound healing

Calcium deficiency signs: 

- Deficiency: similar to Vit. D, poor bone formation, Rickets, Osteomalacia, Soft shell eggs/bones/beaks

                        - Milk Fever (Parturient Paresis): symptoms:

                        - Spasms, Paralysis, Dilated pupils, Staring eyes, Dullness, Ataxia, Recumbency, Listlessness, Anorexia, Muscle degeneration, Rumen stasis, Reduced respiratory rate, Reduced passage rate, Drop in temperature, Cold extremities, Death

-       Phosphorous deficiency signs: 

o   Reduced reproductive performance due to ovarian dysfunction, depression/irregular estrus

o   Poor growth, rickets, osteomalacia, stiff joints, muscular weakness

o   PICA- depraved appetite

o   Signs similar to a calcium or vitamin D deficiency

-       Sodium deficiency signs: 

o   Causes cannibalism in birds

o   Dehydration; Total loss of extracellular fluids,

o   High Hematocrit (packed red blood cells)

o   Decreased Blood Pressure

o   Muscle Cramps

-       Potassium deficiency signs: 

o   Unlikely, unless severe fluid loss from body

o   Retarded growth, weakness, tetany, and death 

-       Chlorine deficiency signs: 

o   Unlikely unless body water loss is high (vomiting, diarrhea)

o   Achlorhydria (insufficient HCl)

o   Alkalosis (inadequate Cl compensated for with bicarbonates)

-       Magnesium deficiency signs: 

o   Results in:

            -Grass staggers/ Tetany (Wheat Pasture Poisoning)

      -Occurs in ruminants grazing winter pastures (wheat and rye) and also new growth of grasses in the spring.

                                    -May be due to acid-base imbalance or N and K fertilizer

o   Symptoms:

§  Muscle tetany, head retraction, staggering, convulsion, heightened sensitivity to noise / touch

-       Sulfur deficiency signs: 

Unlikely, unless feeding ruminants NPN and protein is also deficient

-       Magnesium function: 

- #1 function: Cofactor for the activation of over 300 enzymes involved in the transfer of phosphorus (ATP). e.g creatine kinase, pyruvate carboxylase, TCA enzymes etc

                        - Necessary for Normal:

o   Heart function (contraction and relaxation)

o   Nerve function

o   Muscle function (relaxation more than contraction)

-       Sulfur function: 

- Required as a component of certain important compounds:

                                    - Sulfur amino acids, proteins (hb), thiamin, biotin, insulin, CoA, Chondroitin Sulfate, (structural component of bone, skin, hair , fur, feathers, collagen)

- Important for acid-base balance

                        - Important for wool formation (contains 4% S)

                        - Involved in the drug-detoxifying pathways of the liver.

-       Chlorine function: 

o   Principal ANION both intra/extra cellular

o   Principal anion in gastric juice (HCl)

o   pH regulation

o   Acid/Base balance

o   Maintenance of electrical balance for sodium and potassium intra/extra cellular 

Calcium function: 

ü  Skeleton/ Teeth

ü  Muscle Contraction

ü  Nerve Function

ü  Blood Clotting

ü  Electrolyte or Acid/Base Balance

ü  Egg Shell Quality

Phosphorous function:

ü  More functions than any other mineral

ü  Skeleton/Teeth

ü  Acid/Base balance

ü  Energy Metabolism, Carbohydrate, Lipid, Protein metabolism

ü  Muscle Contraction & Metabolite Transport

ü  Skin/Membrane structure

ü  Nucleic Acid structure 

-       Sodium function: 

o   Principal extracellular cation

o   Acid-Base Balance and pH regulation

o   Regulation of body fluid volume/ osmosis

o   Muscle contraction & nerve impulse transmission

o   Active absorption of nutrients e.g. carbohydrates

o   Buffering agent

-       Potassium function: 

o   Principal intracellular cation.

o   Osmotic regulator (with Na, Cl, bicarbonate ions)

o   Acid base balance

o   Nerve impulse transmission                    

o   Muscle contraction (most common cause of muscle cramps)

o   Activation of numerous intracellular enzymes associated with carbohydrate, lipid, and protein metabolism.

Buffering agent 

Chromium function: 

–      Enhances Insulin action thus improving glucose utilization

–      Enhances conversion of glucose to body fat 

Cobalt function: 

component of B12

Copper function: 

part of ceruloplasmin (which is integral for Fe metabolism)

ü  Norepinephrine and Dopamine synthesis

ü  Fat metabolism

ü  Hematopoiesis -the formation and development of blood cells

ü  Co-Factor for the enzyme:

–      Tyrosinase - Melanin formation (Hair, wool, feather pigmentation)- one of the deficiencies of Copper is depigmentation

–      Superoxide dismutase- destroys free radicals

–      Lysyl oxidase – collagen and elastin cross linking

–      Cytochrome oxidase – electron transport

ü  Component of proteins:

–      Ceruloplasmin- iron metabolism; cooper and iron linked

–      Erythrocuprein –occurs in rbc; important for O₂ metabolism; has superoxide dismutase activity

-       Fluorine function: 

o   No essential function has been described but

ü  It protects against the demineralization of calcified tissues

Iodine function: 

Most found within the thyroid (70-80%) where it serves as a component of thyroid hormones – T3 (Triiodothyronine) and T4 (Thyroxine); as T3 and T4:

            - Increases: metabolic rate, fat/ carb utilization, protein synthesis, nerve/bone formation and growth rate 

Iron function: 

Necessary component of:

–      Energy metabolism; (Citrate Isocitrate); (ETS – cytochromes)

–      Enzymes (peroxidase, collagen and neurotransmitter synthesis)

–      Involved in normal immune function

-Manganese function: 

Cofactor of several enzymes involved in carbohydrate, protein and lipid metabolism (e.g activates kinases, hydrolases & is a constituent of pyruvate carboxylase)

            -Necessary for the synthesis of mucopolysaccharide which is important for synthesis of cartilage (organic matrix of bone)

            -Can take the place of Magnesium in some enzyme systems.

Molybdenum function: 

-       Cofactor in enzyme systems:

o   Xanthine Oxidase (a metalloenzyme that converts purine derivatives like hypoxanthine and xanthine to purine excretory products like allantoin, which is passed out in the urine.)à uric acid accumulation: gout

o   Nitrogenase in the root nodules of legumes (required for nitrogen fixation in nodules)

o   Involved in cytochrome reduction

            -Selenium function: 

            -Component of glutathione peroxides enzyme

ü  Cofactor for:

–      Destroys peroxides

ü  Spares Vitamin E

ü  Prevent heavy metal toxicity in concert with Vit E

ü  Component of Selenoproteins

ü  Absorption

–      Converted to selenocystine or selenomethionine by rumen microorganisms

–      Absorbed as the amino acids

- Zinc function:

ü  Involved in protein metabolism and nucleic acid synthesis

ü  Normal wound healing & immunity / T cell function

ü  Prostaglandin Synthesis & reproductive system development

ü  Bone development and taste mechanism – inability to taste in deficiency

ü  Cofactor for over 200 enzymes and also proteins-

–      Carbonic anhydrase which is necessary for acid-base balance in the blood

–      Retinal dehydrogenase: visual pigment

–      Superoxide dismutase: detoxification of peroxides

–      Retinol-binding protein (Vit A transport)

–      Lactate dehydrogenase

–      Pancreatic carboxypeptidase

-       Calcium hormonal regulation: 

-       Milk Fever can be caused by:

o   Plasma estrogen activity: increases 30 days pre-partum which decreases appetite and thus, decreases Ca intake

o   Delay between hormonal stimulation and actual Ca release

§  Ca absorption increases 24 h after Vit. D3 stimulation

§  Ca mobilization occurs 48 h after stimulation by PTH and Vit. D3

§  This delay coupled with the high demand in milk/colostrum in 1^st 24 hrs causes disease

-       Regulation:

                                    - 1. PTH: Increases blood Ca⁺⁺ by:

·      Increasing: bone mobilization, resorption from proximal kidney nephrons, and absorption from the GIT

                                    - 2. Vitamin D: (Same as above)

                                    - 3. Calcitonin: Decreases blood Ca and Increases Ca⁺⁺ deposits in bone

-       Sodium hormonal regulation: 

-       Plasma sodium is controlled by ALDOSTERONE

-       Plasma Sodium drops à Anterior Pituitary releases ACTH à ACTH stimulates the Adrenal Cortex à Aldosterone is released à Target tissue: kidney

-       Important to maintain plasma sodium levels because of blood pressure regulation, Acid/Base balance, etc. 

- Iodine hormonal regulation:

ü  Hypothalamus releases thyroid releasing hormone

-Anterior Pituitary releases which releases thyroid stimulating hormone 

-Thyroid releases T₃ and stimulates production of thyroglobulin (form in which T₃ & T₄ are transported).

-Cold weather stimulates the thyroid

-Warm/hot weather depresses thyroid function

Which minerals are controlled by a mucosal block?

IRON, COPPER, ZINC, COBALT, MANGANESE