Transcript Chemistry/Biology Warm-up

Chemistry/Biology Warm-up
Dr. Craig Kasper
Basic Elements*
Element
Symbol
Common Forms
Carbon
C
CO, CO2, CnHnOn, COOH
Hydrogen
H
H2, H20,
Oxygen
O
O2
Nitrogen
N
N2, NO2, N03, NH3, NH4+
Phosphorus
P
PO3-, PO4
Sulfur
S
S, HS-
*Keeping a periodic table of the elements around isn’t a bad idea.
Everyday Nutrition Terms
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Nutrition
Feed Conversion Ratio/Feed
Efficiency (FCR/FE)
Protein Synthesis
Protein Turnover
Energy
Nutrient vs. Non-nutrient
Feed rate (fixed vs. satiation)
Pelleted vs. Extruded Diets
Heat (loss)
Fecal
Composition of Gain (protein vs.
fat)
Calorie
Growth
Maintenance
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Protein
Lipid (fat)
Carbohydrate
Cholesterol
Vitamin
Mineral
Amino acid
Fatty acid
Requirement
Essential vs. non-essential
Digestion
Metabolism
Feed formulation
Feed ration
Everyday Biology Terms
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Poikilothermy (-ic)
Temperature
Density
Ammoniotelic
Teleost
Think Like A FISH!!
• Several factors make fish nutrition more
challenging (and exciting) than that of
terrestrial nutrition.
• You must think like a fish, understand it’s
evironment and understand basic nutrition
before you will be able to maximize your
fish growth or reproductive performance.
Zoological
• Oddity: >40,000 species of fish exist
(Compared to 167 species of chicken, or a
dozen, or so cows and pigs, this means
much more potential work).
• Result: Large interspecific diversity.
Variability of requirements.
Biological
• Oddity: a. Larval Stages
b. Continuous growth
c. Potential absence of stomach
• Result: a. Unknown factors
b. Age-specific nutrient needs
c. Unique digestive processes
Ecological
• Oddity: Low average body temperature.
• Result: Limited gut bacterial action?
Difficulty maintaining membrane fluidity.
Unique requirement for certain fatty acids.
Ecological
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Oddity: Highly dense environment AND low oxygen
availability.
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Result:
-Need for considerable ventilation.
-Frequent use of anaerobiosis, hypertrophy of
white muscle.*
-Large amount of protein needed for synthesis of
this material.
-Reduced importance of skeleton
-Low requirements for Calcium and Phosphorus
(*REM: glycolytic=low oxygen)
Ecological
• Oddity: Environment rich in certain elements!
• Result: Supply of some nutrients directly from
environment.
• Oddity: Unique aquatic food chains (carnivores
dominate).
• Result: Different efficiencies of energy sources
(much protein catabolism and limted carb. use.)
Ecological
• Oddity: Abundance of polyunsaturated fatty
acids.
• Result: Loss of bioconversion ability.
Fish Nutrition History
Dr. Craig Kasper
FAS 2240C
What is fish nutrition?
“Nutrition is the process by which an
organism ingests, assimilates and utilizes
various nutrients and converts them into
body tissues and/or activities.”
–Robinson et al. 2001
What is Nutrition?
• Nutrition: the provision of all indispensable
nutrients in adequate amounts to insure proper
growth and maintenance of body functions
• involves various chemical reactions and
physiological transformations which convert foods
into body tissues and activities
• involves ingestion, digestion and absorption of
various nutrients
• transport into cells
• removal of unusable elements and waste products of
metabolism
History of Nutrition I
• Lavoisier is generally credited as being the “father” of nutrition
• until the first quarter of 19th Century, we thought the nutritive
value of food resided only in one component
• near the end of the 19th Century research started to focus
primarily on the need for protein, lipids and carbohydrates
• minerals were considered important, but their essentiality was
unknown
History of Nutrition II
• Great expansion in 20th Century nutrition with the
discovery of vitamins, role of amino acids, more
minerals
• Your body needs >40 nutrients for normal growth and
maintenance (fish may be even more.)
• Why all the attention??? Human health/problems.
• Basic studies of the functioning of the animal organism
supplemented research
History of Nutrition III
• Example of historical nutritional research:
• heifers fed wheat-based diets produced calves at
lower rates than those fed corn diets
• assumption: something toxic in wheat
• analysis: nothing toxic in tissues
• reality: vitamin deficiency
• scientific methods for formulating feeds were
inadequate
• research diets eventually simplified/purified
History of Nutrition IV
• First vitamin discovered in 1913
• pioneer nutritional work achieved primarily through the
use of animal subjects
• same today, but with restrictions
• rats  vitamins, amino acids, minerals
• dogs  insulin, nicotinic acid
• guinea pigs  prevention of scurvy
• chicks  thiamin and other vitamins
• bacteria  growth factors, nutrient function in
metabolism
• final answers must be derived from species studied
Nutrition Today
Animal nutrition today is multidisciplinary:
• metabolism: physiologists, biochemists
• vitamins: organic chemists
• isotopes/chromatography: physicists
• protein structure: molecular biochemists
• breed variation: geneticists
• vitamins/amino acids: microbiologists
• additives/improved digestibility: food technologists
Issue: Overexpansion
• Everyone now-a-days appears to be an expert in
nutrition
• infomercials, algae, diet fads
• claims of superiority without scientific evidence (science
vs. pseudoscience)
• example: massive doses of vitamins are useless, often
toxic
• nutrition industry might need to become more
conservative
• it’s no wonder why the average consumer is puzzled!!
Nutrient Essentiality
• essential nutrient: one that must be provided in the diet
in order to insure adequate growth and maintenance,
indispensable
• Nutrient categories: macro and micro
• macronutrients: protein, lipid, carbohydrate, etc.
• micronutrients: trace metals, vitamins
• important: molecular weight is not the basis,
requirement level is
• proteins: g/kg vitamins: µg/kg
• large requirement doesn’t imply greater importance
(example: Se in sheep 0.1 mg/day)
Basic Nutritional Concepts
• Animal nutrition is tied back to food crops and ultimately
to the nutritive value of soil
• strong interrelationship between human and animal
nutrition
• foods/feeds of both contain similar nutrients
• metabolic processes are basically similar
• nutritional niche of animals: animals concentrate
nutrients of food crops into more nutritious and palatable
forms for humans
• point: animals take sources unsuitable for humans
and improve their quality for us!
Animals as Primary Consumers
• Animals produce meat, milk, etc. on land that is often
unsuitable for production of food crops
• problem: overall land availability vs. protein demand
• fisheries flat, agriculture barely keeping up
• nutrition has greatly improved production capacity, however
it is not going to be enough
What Does it All Mean?
• If agriculture is barely keeping up with world food
demand and…
• Fisheries are being improperly managed to the point
of steady state…
• Either we must quickly apply Iowa corn field
technology to all aerable land on Earth, or food must
be found from other sources! (Roaches??)
• One possible option is aquaculture.
Current Challenges/Problems
• For aquaculture to contribute more to the world’s food
supply, production must be intensified
• higher yields must be achieved in ponds
• better and more predictable natural sources of nutrition
(natural productivity) must be available (too
unpredictable)
• more crude feed materials used as supplements or…
• compounded feeds must provide all nutrients
• retention vs. digestibility: Which is best metric?
Next Time…
• Quiz 1: Terminology
• Topic 2: Fish Behavior, Feed Intake,
Environmental Factors (Why are aquatics
different than terrestrials?)