Exam 3 Material

Question 1

mineral classification

Answer 1

7 macro (major) elements and > 16 micro (trace) elements are required

• Microminerals: are present in body tissues at small concentrations (<50 mg/kg or <50pp)
• Macrominerals: are present in concentrations larger concentrations

Question 2

nutritionally important major essential minerals

Answer 2

calcium
phosphorus
potassium
sodium
chlorine
sulfur
magnesium

Question 3

nutritionally important trace essential minerals

Answer 3

iron
zinc
copper
molybdenum
selenium
iodine
manganese
cobalt

Question 4

mineral absorption in the SI

Answer 4

micromineral absorption: duodenum, jejunum, and ileum

macromineral absorption: jejunum and ileum

Question 5

functions of minerals

Answer 5

Enzyme activation (most essential minerals catalyze >1 cell reaction)
Acid-base and water balance (Na+, K+, Cl-)
Skeletal structure (Ca, P, Mg in bone; S in keratin)
Unique functions EX: Fe in heme: Co in vitamin B12; I in thyroid hormones

Question 6

factors affecting mineral requirements

Answer 6

Physiological state/level of production
Interactions with other minerals
Tissue storage
Form fed

Question 7

deficiencies and excesses of minerals

Answer 7

Most minerals have an optimal range, below which deficiency symptoms occur, and above which toxicity symptoms occur
Mineral content of soils dictates mineral status of plants and; therefore, feeds
-Plant stage of maturity can affect mineral content and nutritional interactions
Deficiency or toxicity symptoms may take months to develop

Question 8

calcium

Answer 8

About 99% of the Ca stored in the animal body is in the skeleton (bones and teeth)
Can draw on Ca stored in bone to maintain consistent level in blood to tissues
Major role: structural (bone)
Additional functions:
-Blood clotting
-Rhythmic heart action
-Neuromuscular excitability
-Enzyme activation
-Permeability of membranes

Question 9

calcium in the diet

Answer 9

Good sources:
Legumes, green leafy crops
Milk, meat, and fish
Supplements such as limestone, Dical (mix 28% Ca, 18% P), oyster shell
Poor sources: cereals and roots

Question 10

phosphorus

Answer 10

Composes approximately 1.1% of the fat free body
Present in organic form in soft tissues…where have we seen them?
Lipid transport, cell-membrane structure
Bioenergetics
80% of body P is in bone

Question 11

phosphorus in the diet

Answer 11

Good sources:
Milk, meat, and fish
Grains: variable (due to phytates)
Poor sources: forages and crop residues

Question 12

bioavailability of P in feed sources-Factors affecting intestinal absorption:

Answer 12

• Ca:P ratio
• Large intakes of Fe, Al, Mg interfere with P absorption
• P contained in phytate salts (esp. cereals) is biologically unavailable unless have phytase

Question 13

bioavailability of P in feed sources-use of phytase to improve P availability

Answer 13

Dietary supplementation with synthetic phytase
-Increase intestinal absorption of P
-Decreased need for supplementation inorganic P
-Decreased P excretion, environmental pollution
Other approaches
-Genetic engineering of plants
-Genetic engineering of animals

Question 14

important concepts about Ca and P

Answer 14

Both Ca and P are required for normal bone formation, as well as many non-skeletal functions
Ratio of Ca to P in diet is as important as the absolute level of either mineral-1:1 or 2:1 is good for most animals (Exception: laying hens need more Ca)
Deficiency of Ca, P, (or Vitamin D), causes:
-Rickets in growing animals
-Osteomalacia in adults
-Milk fever (hypocalcemia, parturient paresis) in lactating animals

Question 15

magnesium

Answer 15

50% of body Mg is in bone
Associated with Ca and P
Mg in soft tissues is concentrated within cells (liver, skeletal muscle have highest soft tissue concentrations)
Major role:
-Bone structure
-Important enzyme activator, especially for energy transduction reactions
-Regulation of ion channel function EX: Na+, K+ ATPase activity in skeletal muscle

Question 16

magnesium deficiency symptoms

Answer 16

Growing rats: anorexia, decreased weight gain, nervous irritability, tetany
Pigs: skeletal malformations, nervous irritability, tetany, death
Milk-fed calves: hypomagnesemia, decreased bone Mg, tetany
Adult ruminants fed lush pasture: hypomagnesemia, tetany (or grass staggers), death

Question 17

magnesium in the diet

Answer 17

Good sources:
-Wheat bran
-Legumes
-Most protein concentrates
-Supplement: magnesium oxide (MagOx)
Poor sources:
-Forages (variable)

Question 18

the electrolytes

Answer 18

Potassium
Sodium
Chlorine
Major role in acid: base balance in the body
-Kidney excretes excess Na and K as one method to maintain blood pH homeostasis

Question 19

acid-base balance

Answer 19

Involves interaction of cations (Na, K) and anions (Cl, S)
Important to monitor the dietary cation: anion difference (DCAD)
-This is the acid: base balance
Basic equation: (Na + K)-(Cl+S)
-Ca, Mg, P, HCO3- can also be included in the equation

Question 20

DCAD

Answer 20

If its <0, then the animal will mobilize cations to compensate and will try to buffer to increase pH
-The animal in a state of ACIDOSIS
If its >0, then the animal will mobilize anions to compensate
-The animal will be in a state of ALKALOSIS
Animals typically ~10-20 mEq/l

Question 21

iron

Answer 21

Poor Absorptive Efficiency:
-Heme (~15%), Fe2+ (<5%), Fe3+ (trace)
Major role:
-O2 transport in blood (hemoglobin) and muscle (myoglobin)
-Cofactor in oxidative reactions
Deficiency: Anemia (common in piglets)

Question 22

zinc

Answer 22

Absorbed at about 20-30%
Major role:
-Component of many important enzyme (>200)
-Stabilization of membranes
-DNA binding
-Oxygen radical metabolism
Deficiency (caused by high Ca, high Cu, phytates): parakeratosis, depressed growth performance

Question 23

selenium

Answer 23

In all cells of the body
-Liver, kidney, muscle contain the highest
Component of glutathione peroxidase
-Protects cellular membranes from peroxide
Component in other selenoproteins
Stored as selenomethionine and selenocysteine
Interacts with Vitamin E
Deficiency: nutritional muscular dystrophy (white muscle disease), exudative diathesis, liver necrosis ill thrift (ruminants), reproductive problems
Toxicity: alkali disease, blind staggers

Question 24

manganese

Answer 24

High requirement for poultry
-High Ca impairs Mn absorption
-High Fe impairs Mn absorption
Toxic at high levels for pigs
Deficiency: retarded growth, skeletal abnormalities (lameness in pigs), ataxia, reproductive failure, perosis or slipped tendon, reduced shell thickness, fatty livers

Question 25

iodine

Answer 25

Important for the synthesis of hormones thyroxine (T4) and triiodothyronine (T3) Function in lipid, carbohydrate, nitrogen metabolism, regulation of energy metabolism, growth and development, reproductive performance Deficiency: Goiter Diet induced: high intakes of brassica crops, soybeans, linseed, peas Toxicity: depressed performance

Question 26

cobalt

Answer 26

Constituent of Vitamin B12 Incorporated into B12 by bacteria Can’t make B12 if you don’t have cobalt Deficiency: Occurs in ruminants (“wasting disease”)→ result of B12 deficiency but B12 deficiency is caused by Cobalt deficiency Inability to synthesize vitamin B12 Symptoms: anemia, listlessness, lack of appetite (sometimes causing death) Most severe deficiencies in the US are in New England and lower Atlantic plain Coastal regions Supplementation: sulfates, Co-I salt, Co bullets, fertilize with CoCO4

Question 27

vitamin classifications

Answer 27

fat soluble: ADEK | water soluble: B, C

Question 28

features of vitamins

Answer 28

Chemically and biologically diverse, and therefore hard to classify Not metabolic fuels (like glucose, fatty acids) or structural nutrients (like amino acids, Ca, P) Mostly catalysts (facilitators) of the metabolism of other nutrients All vitamins are metabolically essential but not all are necessarily required in the diet, depending on the diet and the vitamin concerned Examples: -Most mammals can synthesize vitamin C (ascorbic acid), primates (incl. humans) cannot -No mammals can synthesize B vitamins but ruminants obtain adequate supply from bacterial synthesis in the rumen

Question 29

provitamins

Answer 29

``` function as vitamins only after undergoing a chemical change in the body EX: beta-carotene→ vitamin A ```

Question 30

Many vitamins interact with other nutrients, most notably minerals:

Answer 30

``` White muscle disease in young ruminants: Se, vitamin E Cobalt deficiency in ruminants (wasting disease): Co, vitamin B12 Milk fever (parturient paresis) in dairy cows: Ca, P, vitamin D ```

Question 31

vitamin A

Answer 31

Important in cell growth (part of transcription factor), vision (retina) Both deficiency and toxicity are serious health hazards All animals require a dietary source of vitamin A Higher concentrations in fish oils, milk fat, egg yolk, liver Active vitamin A does not occur in plants

Question 32

provitamin A

Answer 32

``` Plants contain provitamin A Provitamin A (the carotenoids): the most abundant and widespread provitamin A in animal feeds is beta-carotene (think orange) Provitamin A carotenoids (EX from plants) and preformed vitamin A (from animal tissue) are absorbed with dietary lipid from the small intestine Beta-carotene is converted to active Vitamin A in intestinal (and other) cell ```

Question 33

active vitamin A

Answer 33

Active vitamin A (in the form of retinyl esters) is transported in bloodstream The primary active form of vitamin A is retinol -Can be converted to other forms (EX: vitamin A ester) for storage in liver and other tissues About 90% of the body’s vitamin A is stored in liver (retinyl palmitate)

Question 34

storage of carotenoids

Answer 34

Carotenoids that escape intestinal conversion to retinol can be stored in adipose tissue and included in milk and egg lipids, giving fat, milk, and egg yolk a yellow pigment

Question 35

vitamin D

Answer 35

2 active forms, both steroid derivatives D2: Ergocalciferol D3: Cholecalciferol Both produced from sterol precursors (provitamins) which are more widely distributed in feeds than “ready made” vitamin D (not much active D in foods)

Question 36

vitamin D major actions

Answer 36

Increase intestinal absorption of Ca and P Increase bone resorption Decrease urinary excretion of Ca and P

Question 37

vitamin D and calcium metabolism

Answer 37

Vitamin D promotes absorption of Ca (&P), bone resorption of Ca (&P) Vitamin D inhibits urinary excretion of Ca (&P)

Question 38

vitamin D, Ca, and P deficiencies

Answer 38

Deficiency of Ca, P, (or Vitamin D) - Causes - -Rickets in growing animals - -Osteomalacia in adult animals - -Milk fever (hypocalcemia, parturient paresis) in lactating animals

Question 39

what vitamin is activated by UV radiation

Answer 39

vitamin D

Question 40

vitamin E

Answer 40

Vitamin E is the general name for a group of closely related compounds called tocopherols Alpha-tocopherol is the most biologically active and most widely distributed in feeds Biological functions include antioxidant activity, protection of membrane integrity of cells and organelles Higher concentrations in green leafy forages, most cereal grains (always depending on quality)

Question 41

vitamin E and Se

Answer 41

Both are important in cell protection BUT have independent (complimentary) roles Remember that Se is required for the formation of the enzyme glutathione peroxidase -Destroys peroxides (H2O2) Vitamin E acts as scavenger to destroy peroxide that escapes destruction -Forms complex to take up (then pass along) H

Question 42

vitamin K

Answer 42

Required for blood coagulation K1 (phylloquinone) synthesized by plants K2 (menaquinones) main storage in animals Colonic bacteria convert K1 to K2

Question 43

b vitamins

Answer 43

``` B1: Thiamin B2: Riboflavin B3: Niacin B5: Pantothenic Acid B6: Pyridoxine B7 (H): Biotin B9 (M, Bg, Bc): Folacin B12: Cyanocobalamin ?? (Bp): Choline ```

Question 44

general features of b vitamins

Answer 44

Present in all plant and animal cells, widely distributed in feeds Generally act as components of coenzymes in energy-yielding reactions Dietary requirement is closely linked to metabolic rate Ruminant requirements are met entirely by rumen bacterial synthesis Little tissue storage (except B12, some folic acid)-must be continually supplied in diet or by ruminal synthesis

Question 45

interrelated functions of b vitamins

Answer 45

Several B vitamins have closely interrelated general functions, but each has a distinct specific role EX: general process of oxidative decarboxylation, which requires coenzymes derived from thiamin, riboflavin, nicotinamide (niacin), and pantothenic acid

Question 46

pantothenic acid

Answer 46

an essential component of coenzyme A (CoA) | -b vitamin

Question 47

nicotinamide (niacin)

Answer 47

required for synthesis of NAD | -b vitamin

Question 48

thiamin

Answer 48

required for synthesis of thiamin pyrophosphate (TPP), an essential component of the pyruvate dehydrogenase complex -b vitamin

Question 49

riboflavin

Answer 49

required for synthesis of flavin adenine dinucleotide (FAD), a coenzyme which assists transfer of H+ to NAD+ -b vitamin

Question 50

vitamin b12

Answer 50

Sources: -Microbial synthesis is the only significant origin of vitamin B12 -Widely distributed in animal tissues, especially high content in lover -Plants contain little or none Metabolic functions: -Essential coenzymes for: --Conversion of ribonucleotides to deoxyribonucleotides (DNA synthesis) --Transfer of methyl groups in methylation reactions EX: bacterial synthesis of methionine --Propionate metabolism

Question 51

feedstuff

Answer 51

the individual components of feed

Question 52

classes of plant feeds

Answer 52

forages grains roots, tubers byproducts

Question 53

forages

Answer 53

Leaves and stems of grasses (including cereals), legumes, brassicas Typically high in fibre (>18% of DM), which means high in carbohydrate Includes: -Fresh -Hay -Silage -Crop residue

Question 54

roughages

Answer 54

includes most fresh and conserved forages

Question 55

grass silage DM

Answer 55

36.5%

Question 56

grass hay FM

Answer 56

88.1%

Question 57

what is the relationship between niacin and NAD

Answer 57

niacin is a part of NADs structure

Question 58

forage nutritive value

Answer 58

Factors affecting nutritive value of forages: - Maturity - Leaf-stem ratio - Species and cultivars

Question 59

forage nutrient major anatomical parts

Answer 59

``` leaves: -More nutritious -Higher in non-structural carbohydrate (and protein) --Higher proportion of alpha-linked, lower proportion of beta-linked -Lower in structural carbohydrate stems: -Less nutritious -Higher in structural carbohydrate --Higher proportion of beta-linked -Vascular tissue ```

Question 60

younger vs older plants

Answer 60

Younger plants tend to be more nutritious because they tend to have more leaf compared to older plants which tend to be less nutritious because they have less leaf

Question 61

concentrates

Answer 61

includes most grains and high quality byproducts - <32% NDF or 22% ADF - High in energy

Question 62

grains

Answer 62

``` Seeds of cereals, oilseed plants Cereal grains produced by members of the grass family, example: -Corn sorghum -Wheat -Barley -Oats -Rye Affected by the environment (soil profile, precipitation, etc…) ```

Question 63

cereal grains

Answer 63

``` Typically low in nitrogen (8-12% of DM) -Mostly in the form of protein (85-90%) -Tend to be low in lysine, tryptophan (corn), threonine (sorghum, rice) Variable fat content (1-6%) -High in linoleic and oleic acid Higher carbohydrate -Primarily starch ```

Question 64

oilseed grains

Answer 64

oilseeds: protein and lipid-rich Most important source of plant-based proteins are from soybeans and cottonseed Protein sources also from: -Peanuts, flax, sunflower, sesame, safflower, other legume seeds

Question 65

bulbs, roots

Answer 65

``` Includes turnips, beets, swedes, radishes High water (75-90%) High carbohydrate (50-75% of DM) -Mostly sucrose Low fiber (5-11% of DM) Low crude protein (4-12% of DM) Low Ca, P, high K ```

Question 66

byproducts of plant processing

Answer 66

Extremely variable chemical composition Meals (byproducts of pressing/processing: soybean, canola, sunflower, cottonseed, etc.) Human food byproducts: -Vegetable plots (carrots, brussel sprouts, etc) -Products from vegetable wastes such as pulps pomaces -From processing plants -Viticulture and brewery wastes Molasses

Question 67

What are some factors that affect nutritive quality of plant-based feedstuffs?

Answer 67

``` Age Storage Leaf to stem ratio Soil Species of plant ```

Question 68

soybean meal

Answer 68

the most popular protein supplement in dairy cattle rations

Question 69

common protein rich plant based feedstuffs

Answer 69

“Meals”: soybean, canola, corn, cottonseed, linseed, peanut, safflower, sunflower Some additional byproducts: brewers grain, corn distillers Some forages: esp. Legumes, lupins, other mixed forages (also depending on fertilizer use, stage of maturity, etc)

Question 70

Examples of crude protein (N) content of various protein sources:

Answer 70

``` Forages: 2-25% CP -Straws: <7% CP -Corn silage: <9% CP -Hays and forage silage: 7-25% CP Grains: 8-14% CP Oilseed meals/grain byproducts: 30-55% CP Animal protein sources: 50-95% CP NPN such as urea: <281% CP ```

Question 71

Common carbohydrate-rich feedstuffs:

Answer 71

Typically looked for alpha-linked carbohydrates -There are some exceptions, for instance ruminants also need NDF Some good alpha-linked carbohydrate sources -Corn (as grain, ground, rolled, flaked, silage, etc…) -Most grains (barley, oats, wheat, rye, sorghum_ -Most pulps and pomaces (citrus, beet, apple) -Molasses

Question 72

To reach energy requirements using plant-based feedstuffs

Answer 72

Typically include carbohydrate or fat dense materials in ration to boost energy density of feeds - See list of carbohydrate-rich feeds - Also: high fat feedstuffs such as oils, some byproducts (candy and bakery waste can be useful here)-but more common sources from animal-based products

Question 73

processing of dry forages

Answer 73

Bailing: conventional square, large round, large square -Some nutritional considerations for baling hay --Plant quality at baling affects forage quality (dry forage quality will never be better than fresh forage quality) --Time of day affects DM content of hay --Weather during drying of hay will affect nutrient quality ---EX: if it rains after you have cut the hay but before you have baled it, quality decreases --Over drying will decrease nutritional quality --Nutritional quality of high legume hay will be affected by leaf shatter Chopping (~2”) or grinding (<1”) Pelleting (after grinding)

Question 74

why process feedstuffs

Answer 74

Maintain or improve nutritive value -Increase digestibility and nutrient accessibility through altered physical form or particle size -Prevent spoilage -Isolate specific parts of the plant/animal Improve handling efficiency, reduce wastage -NOTE: monetary benefits of improved animal performance and/or labor saving must exceed cost of processing

Question 75

wet forages processing techniques

Answer 75

chopping corn silage

Question 76

grains processing techniques

Answer 76

``` Dry processing -Grinding -Dry rolling or cracking -Popping, micronizing -Extruding -Roasting -Pelleting Wet processing -Steamrolling, flaking -High moisture storage (ensiling) -Soaking -Reconstitution -Pressure cooking -Exploding ```