Term
| name the 8 proximate nutrient groups. |
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Definition
Dry matter (or total moisture)
Gross energy (GE - combustible energy)
Crude protein (CP)
Crude fat (ether extract)
Crude fibre
Total starch (including sugars)
Ash (total minerals)
vitamins |
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Term
| method for classical characterization of nutrients for nutritive values. describe price. |
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Definition
| gravimetric (weighing) and volumetric based chemical analyses where each group represents many nutrient compounds. this is inexpensive |
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Term
| briefly list the 3 types of feed and 3 types of additives/supplements as classified by proximate analyses of macronutrient content. |
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Definition
Energy Feeds
Protein feeds /protein supplements
high fibre feeds or roughages
macro-mineral supplements
fat or oil supplements
feed additives |
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Term
| describe the contents of energy feeds. what ingredient is low, and why is this? |
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Definition
high in starch or sugar, but low in crude protein or other nutrients.
low in crude protein because it is not efficient, its costly, and the nitrogen in the animal's waste is bad for the environment. |
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Term
| describe the contents of protein feeds or protein supplements |
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Definition
| high in crude protein (CP) (>30%) or also high in crude fat, but low in other nutrient content |
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Term
| describe the content of high fibre feeds or roughages. Which type of animal is it good for and why? |
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Definition
| high in crude fibre but low in other groups of nutrient content. Very important in ruminant feeding because it is necessary for good marbling. |
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Term
| what types of ingredients are in macro-mineral supplements? |
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Definition
| sodium (Na), chloride (Cl), calcium (Ca), phosphorus (P) or sometimes potassium (K) |
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Term
| describe the role of fat or oil supplements |
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Definition
| they enhance dietary energy density, feed palatability (only in some animal species), reduce dustiness of diet mixture (on air-dry basis) during mixing, handling or delivery. |
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Term
| describe the function and normal quantity of feed additives. |
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Definition
| they are essential function additives that are added to complete balanced diets or rations, and are usually only below 1%. |
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Term
| what is the equation for determining dry matter given total moisture? |
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Definition
| Dry matter (DM) = total weight (100%) - total moisture (H2O%) |
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Term
IMPORTANT CONCEPT.
describe the two types of water. |
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Definition
free water: in a feed matrix material WITHOUT forming hydrogen bonding with other hydrophilic compounds
bound water: in feed or biological matrix materials WITH hydrogen bonding |
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Term
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Definition
| a sealable container used to preserve moisture-senstive items, or protect chemicals that would otherwise react with the water from the humidity |
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Term
| describe the tools and procedure used to measure dry matter in samples. |
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Definition
tools:
hot over at temp between 100-140
analytical balance
desiccator
sample spatula
procedure
1. weigh 1-2 g of sample in duplicate into beakers, with decimal points up to 4 places.
2. place sample in pre-heated oven at 130C overnight
3. take out dried samples and immediately transfer into desiccator (make sure drying agents are in bottom to remove potential moisture in headspace). quickly close lid and let samples cool down.
4. weigh residue sample weights. |
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Term
| when measuring the dry matter in samples, why is the oven range from 100-140C important? in other words, what happens if its too low or too high? |
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Definition
| if too low, water won't boil so H bonds won't break. if too high, you will burn the sample and thus have biased results. |
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Term
| equation for calculation DM % of a sample given sample weights. |
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Definition
| DM % = [(residue sample weight (g) after drying at 130C/sample weight (g) before drying)] X 100% |
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Term
| equation for total moisture content in sample if given % of dry matter. |
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Definition
| total moisture content in samples % = 100% - DM% |
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Term
| give three reasons why measuring dry matter is important. |
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Definition
to predict and manage feed intake correctly
for accurate diet formulations (ie nutrient density)
compare nutrient levels among bulky feed samples (ie 90% vrs. 92% DM) |
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Term
| if the crude protein in a sample is 44.5% on air dry basis, and the DM of that sample is 90%, what is the crude protein % of that sample on a dry matter basis? |
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Definition
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Term
| name 5 common mistakes when trying to experimentally measure dry matter. |
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Definition
oven temp not high enough (below 100C)
not leaving sample in oven long enough
forgetting to put drying compounds in bottom of desiccator (then headspace moisture remains)
lids or covers for desiccators are not well waxed (air leakage)
sample weighing process too long or not fast enough |
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Term
| describe equipment needed and process for measuring "free water" and to obtain "air-dry basis" |
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Definition
equipment:
hot over set between 60-75C
freeze drier for temp sensitive samples or bio-products
top loading or analytical balance
sample spatula
procedure:
1. weigh 1-2 g of sample in two beakers
2. place samples in pre-heated oven at 65C or freeze drier for 4-5 days
3. take out drier samples and leave in containers overnight to allow equilibrium with air moisture
4. weigh residue feed weight
5. calculate % of water loss |
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Term
| when measuring "Free water" or obtaining "air-dry basis" what are the cons of setting the oven below 60 or above 75C? |
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Definition
below, it takes too long
above: its too expensive to heat. |
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Term
| briefly list the three business methods of creating "air-dry" feeds. |
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Definition
1 .good farming
2. industrial scale electronic hydration processing
3. research, governmental regulatory and feed industry labs |
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Term
| when making air-dry feeds using good farming, what is needed? and what is the danger? |
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Definition
must have good sunlight, dry hay, harvesting cereal grains or oil seeds.
if there is a significant amount of free water in the feeds, it can cause moulding and toxicity due to fungal mycotoxins which are health hazardous and increase feeding costs in food production farm animals. |
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Term
| what is the con of using industrial scale electronic hydration processing to creating air-dry feeds? |
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Definition
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Term
| describe the tools used by research, governmental regulatory and feed industry labs when creating air-dry feeds. |
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Definition
a hot oven at 65C for several hundreds of g to kg of feed samples
a freeze-drier for temp. sensitive samples. |
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