Term
| What factors digestibility of nutrients? |
|
Definition
processing (grinding, heat)
source (e.g. plant source)
water temperature
ANFs
interactions w other nutrients |
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Term
|
Definition
| study of energy intake, expenditure and gain |
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Term
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Definition
heat produced / energy required to maintain life
-post absorptive state, TNZ, no stress, awake |
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Term
| Indirect calorimetry proticol |
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Definition
| heat produced when fed - heat produced when fasting = HiF |
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Term
|
Definition
size of the animal
water temperature |
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Term
| What factors contribute to heat increment of feeding? |
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Definition
-digestive & absorptive processes
-formation & excretion of wastes
-transformation/conversion of substrates |
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Term
| What factors affect growth? |
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Definition
-feed quality & quantity
-temperature
-genetics
-environment
-management |
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Term
| Digestible energy requirement = |
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Definition
| energy deposited + cost of living + cost of depositing energy |
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Term
| How would you go about determining energy & feed requirements? |
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Definition
1. Predict growth w/ appropriate model
2. Determine nutrient/energy gained (carcass comp X growth)
3. Estimate MER, HiE, UE, ZE
4. DER = RE + MER + HiE + UE + ZE
5. Divide DER / DE of feed
6. Determine feed req /kg weight gain
7. F:G |
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Term
| What affects protein utilization / absolute dietary requirement of protein? |
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Definition
diet composition
how well the species can efficiently use energy-yielding nutrients |
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Term
| Acronym for 10 essential AA |
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Definition
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Term
| Why do AA requirements vary? |
|
Definition
-mode of expression
-parameters used
-diet composition
-AA profile of ingredients |
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Term
| What are the limitations of the factorial approach to determining AA requirements? (6) |
|
Definition
-growth & intake vary day to day fish to fish
-nutrients are served as a package
-nutrient interactions
-AA use efficiency varies
-energy intake & FCR depend on diet composition
-inevitable catabolism of AAs |
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Term
| What fats do marine crustaceans require? |
|
Definition
mostly w-3, some w-6
phospholipids
sterols |
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Term
| Why is determining lipid requirements complex? |
|
Definition
-some FAs can be substituted for others
-req depend on species & life stage
-small metabolic requirements relative to whole body store |
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Term
| Why is starch used in fish feeds? |
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Definition
-cheaper energy yielding nutrient than protein / fat
-good binding agent provides water stability and density |
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Term
| How can solid waste output be minimized (3) |
|
Definition
-improve digestibility!
-select for ingredients/additives which contribute to feces characteristics e.g. settling velocity
-diet composition can affect physiochemical characteristics of feces |
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Term
| Important points for feed-waste management (4) |
|
Definition
-can use nutrient analysis to predict waste outputs
-can fine tune waste outputs by changing feed ingredients, processing and feeding practices
-managing environmental impact is multifactorial
-small amounts of organic waste can be beneficial |
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