Exam 3 Material Flashcards
mineral classification
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
nutritionally important major essential minerals
calcium phosphorus potassium sodium chlorine sulfur magnesium
nutritionally important trace essential minerals
iron zinc copper molybdenum selenium iodine manganese cobalt
mineral absorption in the SI
micromineral absorption: duodenum, jejunum, and ileum
macromineral absorption: jejunum and ileum
functions of minerals
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
factors affecting mineral requirements
Physiological state/level of production
Interactions with other minerals
Tissue storage
Form fed
deficiencies and excesses of minerals
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
calcium
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
calcium in the diet
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
phosphorus
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
phosphorus in the diet
Good sources:
Milk, meat, and fish
Grains: variable (due to phytates)
Poor sources: forages and crop residues
bioavailability of P in feed sources-Factors affecting intestinal absorption:
- 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
bioavailability of P in feed sources-use of phytase to improve P availability
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
important concepts about Ca and P
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
magnesium
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
magnesium deficiency symptoms
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
magnesium in the diet
Good sources: -Wheat bran -Legumes -Most protein concentrates -Supplement: magnesium oxide (MagOx) Poor sources: -Forages (variable)
the electrolytes
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
acid-base balance
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
DCAD
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
iron
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)
zinc
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
selenium
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
manganese
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
iodine
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
cobalt
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
vitamin classifications
fat soluble: ADEK
water soluble: B, C
features of vitamins
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
provitamins
function as vitamins only after undergoing a chemical change in the body EX: beta-carotene→ vitamin A
Many vitamins interact with other nutrients, most notably minerals:
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
vitamin A
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
provitamin A
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
active vitamin A
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)
storage of carotenoids
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
vitamin D
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)
vitamin D major actions
Increase intestinal absorption of Ca and P
Increase bone resorption
Decrease urinary excretion of Ca and P
vitamin D and calcium metabolism
Vitamin D promotes absorption of Ca (&P), bone resorption of Ca (&P)
Vitamin D inhibits urinary excretion of Ca (&P)
vitamin D, Ca, and P deficiencies
Deficiency of Ca, P, (or Vitamin D)
- Causes
- -Rickets in growing animals
- -Osteomalacia in adult animals
- -Milk fever (hypocalcemia, parturient paresis) in lactating animals
what vitamin is activated by UV radiation
vitamin D
vitamin E
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)
vitamin E and Se
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
vitamin K
Required for blood coagulation
K1 (phylloquinone) synthesized by plants
K2 (menaquinones) main storage in animals
Colonic bacteria convert K1 to K2
b vitamins
B1: Thiamin B2: Riboflavin B3: Niacin B5: Pantothenic Acid B6: Pyridoxine B7 (H): Biotin B9 (M, Bg, Bc): Folacin B12: Cyanocobalamin ?? (Bp): Choline
general features of b vitamins
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
interrelated functions of b vitamins
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
pantothenic acid
an essential component of coenzyme A (CoA)
-b vitamin
nicotinamide (niacin)
required for synthesis of NAD
-b vitamin
thiamin
required for synthesis of thiamin pyrophosphate (TPP), an essential component of the pyruvate dehydrogenase complex
-b vitamin
riboflavin
required for synthesis of flavin adenine dinucleotide (FAD), a coenzyme which assists transfer of H+ to NAD+
-b vitamin
vitamin b12
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
feedstuff
the individual components of feed
classes of plant feeds
forages
grains
roots, tubers
byproducts
forages
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
roughages
includes most fresh and conserved forages
grass silage DM
36.5%
grass hay FM
88.1%
what is the relationship between niacin and NAD
niacin is a part of NADs structure
forage nutritive value
Factors affecting nutritive value of forages:
- Maturity
- Leaf-stem ratio
- Species and cultivars
forage nutrient major anatomical parts
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
younger vs older plants
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
concentrates
includes most grains and high quality byproducts
- <32% NDF or 22% ADF
- High in energy
grains
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…)
cereal grains
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
oilseed grains
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
bulbs, roots
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
byproducts of plant processing
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
What are some factors that affect nutritive quality of plant-based feedstuffs?
Age Storage Leaf to stem ratio Soil Species of plant
soybean meal
the most popular protein supplement in dairy cattle rations
common protein rich plant based feedstuffs
“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)
Examples of crude protein (N) content of various protein sources:
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
Common carbohydrate-rich feedstuffs:
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
To reach energy requirements using plant-based feedstuffs
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
processing of dry forages
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)
why process feedstuffs
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
wet forages processing techniques
chopping corn silage
grains processing techniques
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
