Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
39 Cards in this Set
- Front
- Back
|
What does the feed nutritive value combine information on?
|
- Available nutrient contents
- The characteristic levels of intake - Palatability - Effects on animal health - Product quality |
|
|
What are the three main components to animal feeds?
|
- Roughages
- Concentrates - Miscellaneous |
|
|
What is included in the roughage component of animal feed?
|
>20% fibre
|
|
|
What is included in the concentrates component of animal feed?
|
- >20% fibre
- Energy concentrates: <20% protein - Protein concentrates: >20% protein |
|
|
What is included in the miscellaneous component of animal feed?
|
- Minerals
- Vitamins - Additives |
|
|
Roughages:
|
- Green pasture and forage crops
- Hays (legume, pasture) - Dry, mature pasture, stubbles, straws - Silages (cereal forage, pasture, legume forage) - Fodder trees |
|
|
What are the major components of plant cell wall structures?
|
- Fibrous carbohydrate
- Cellulose - Matrix substances - Hemicellulose and pectin - Lingin |
|
|
What are some factors which inhibit cell wall digestion?
|
1. Lignin is essentially indigestible
2. Lignin may poison some rumen bacteria 3. Lignin protects underlying hemicellulose and cellulose |
|
|
What is the objective of the nutritional value of feed?
|
To estimate how well the nutrients contained in the feedstuff will be utilised for various functions (maintenance, growth, milk production, etc.) and if any anti nutritional factors are present that will influence animal performance
|
|
|
What is involved in processing roughages?
|
- Hay making
- Chaffing - Silage making |
|
|
What is hay?
|
Dried or cured cereal, grass or legume harvested before complete maturity, while at a vegetative stage of growth. May have immature seed or grain present
|
|
|
What is straw?
|
Dried or cured cereal, grass or legume cut at or after complete maturity. Generally has no seed or grain remaining. Low nutritive value due to heavily lignified cell walls (high ADF)
|
|
|
Heating and combustion of hay
|
- If baling at >25% moisture, risk of mould growth, heating and spontaneous combustion
- High risk if >30% moisture at baling - If temp of stack reaches 70C - too hot - could ignite |
|
|
What is a result of over-heating hay?
|
It also decreases energy content and protein digestibility
|
|
|
What animals is mouldy hay dangerous to?
|
- Horses
- Calves - Lambs - Pregnant animals |
|
|
What is silage?
|
Forage harvested at high moisture levels before maturity and preserved by a controlled anaerobic fermentation, in which organic acids (from bacterial metabolism) build up to pH levels at which further bacterial action is prevented.
- Main desired product is lactic acid |
|
|
What are some benefits of silage?
|
- Excellent method of preserving high moisture forages at optimal nutritional composition
- Not as much loss of nutrients as during haymaking - Fire and vermin proof - Will keep INDEFINITELY if correct ensiling conditions are maintained |
|
|
Energy concentrates: Cereal grains
|
- Wheat
- Barley - triticale - Oats |
|
|
Energy concentrates: Sugar Rich Feeds
|
- Molasses
- Whey - Fruit pulp |
|
|
Energy concentrates: Cereal byproducts
|
- Bran
- Pollard - Millrun |
|
|
Energy concentrates: Fats and oils
|
- Vegetable oils
- Tallow - Lard |
|
|
What is the most important grain tissue and why?
|
The endosperm: because it has:
- Cells packed with starch granules in a protein matrix - An outer layer of cells, the aleurone layer, which is protein- and oil-rich |
|
|
What does starch consist of?
|
- Amylose (about 20 to 30%)
- Amylopectin (about 70-80%) |
|
|
What are some inhibitors of cereal grain endosperm digestion?
|
1. Relatively indigestible seed coat
2. Tight packing of endosperm cells 3. Protection of starch granules by a protein matrix 4. Starch chemistry (amylose is more resistant than amylopectin) |
|
|
What are some of the effects on intake, health and production?
|
- Tannins (sorghum) and alky resorcinol (triticale) may reduce palatability
- Alkyl resorcinol causes reduced intake and growth and possibly scouring - Most animals of all species find cereal grains palatable, although a few individuals may not |
|
|
What is acidosis?
|
(A.K.A "grain engorgement poisoning")
- Large amounts of grain may cause over-production of acid when rumen bacteria ferment large amounts of starch - Low pH (5 to 6) leads t rumen stasis, death of rumen protozoa and some bacteria, and absorption of acid into the blood - Excretion of acid in the urine leads to the exhaustion of blood electrolytes and ultimately the animal can not control its blood pH. This can be fatal |
|
|
What are the steps in the processing of grains?
|
Preparation and Processing of grains, Chemical, Thermal, Mechanical
1. Alter physical form of particle size 2. Prevent spoilage 3. Isolate specific part of seed or plant 4. Improve palatability 5. Inactivate toxins or anti-nutritional factors 6. Improve handling |
|
|
What are the nutritive effects of grain processing?
|
- Effects on starch (carbohydrate)
- Effects on protein |
|
|
What are the effects on starch?
|
- Amount of starch digested beyond the rumen of cattle or stomach of horses is markedly less for Steam-Flaked, Reconstituted or Micronised grains, Ground or Dry-rolled grains
- Quantity of starch does NOT chagne, but digestibility and intake of energy does |
|
|
What are the effects on protein?
|
- Grain processing also improves protein digestibility and quality by breaking the protein matrix surrounding starch molecules - especially important for sorghum
- Not that grains meet over 75% of protein requirements in feedlot beef, plus are good sources of rumen BY-PASS PROTEIN |
|
|
What are the cold methods of processing grain?
|
- Hammer mill grinding
- Roller mill: cracking and grinding - Soaking and reconstitution - High moisture grain, ground/rolled/acid |
|
|
What are the hot methods of processing grain?
|
- Steam rolling
- Steam flaking - Extruding - Pelleting - Micronizing - Roasting |
|
|
How does processing effect nutritive value?
|
Heating of cereal grains gelatinises starch and increases nutritional value in dogs, cats, poultry, but not for ruminant or horses
|
|
|
What does excessive heating of grain result in?
|
- Malliard reactions between proteins and carbohydrates
- Decreased vitamin content - Heating increases rancidity of fat |
|
|
Response to processing is variable and depends on:
|
- Type of grain
- Animal species/type - Feeding systems used - The physical form of the final product |
|
|
What animals prefer a pelleted diet?
|
- Pig
- Broilers - Laying hens - Captive Kangaroos and emus |
|
|
What are dairy cattle, beef cattle, horses, sheep, goats and deers often fed?
|
Pelleted ingredients under supplementary feeding situations, but hammer-milled or rolled grains are more common and generally less expensive
|
|
|
What feed to feedlot beefy, dairy and sheep commonly receive?
|
- Dry-rolled
- Steam-flaked - Reconstituted/temperature grains |
|
|
What do dogs, cats and aquaculture receive?
|
Extruded feeds
|
