Lecture 2- Feeds Flashcards
What is the most expensive economic input for a livestock producer?
-feeds
What is malnutrition and what are its effects?
-either insufficient or over sufficiency in nutrient supply -Insufficient intake of nutrients results in decreased performance and possibly death (starvation) -Excessive nutrient consumption results in obesity, other metabolic dysfunction (and possibly death)
What is a feed?
• Diet or ration • A mixture of feedstuffs (most diets will have multiple ingredients)
What is a feedstuff?
• Ingredient in diet or ration
What does a typical feed analysis look like?
- get proportions of the major macromolecules
- can tell if it is high in carbohydrate or protein and need to balance protein to energy
What are the 3 categories of animals, in terms of their diets?
1.
What are the 5 sources of plant based foods?
What are the two categories of feed?
- Concentrates 2. Roughages
What are the characteristics of a concentrate feed?
– Low in fibre content (20% CP (e.g. soya)
What are the characteristics of a roughage feed?
– High fibre content (> 18% crude fibre) – Bulky materials, with low nutrient density -lot of fibre, crucial for ruminants but also important in other animals, eg. in humans for colon health
What are the by-products source of feed and the advantages and disadvantages?
-by products: from industrial production of food, most often cheap • Advantages -contain useful nutrients - frequently very inexpensive • Disadvantages - variable nutrient content from batch to batch - variable availability on a consistent basis -there are laws limiting what sort of feed you can give an animal depending on the particular digestive system it has
What are the characteristics of energy feeds?
• High in starch: >70% • In grains, starch is mainly located in the endosperm • High digestibility: > 85% DMD • Low in protein: 8 to 14%. • In grains, embryo is the only source • Generally deficient in calcium and some vitamins (e.g. vitamin A) -lot of easily accessible energy -high in carbohydrates and low in proteins
What is the cost evaluation of feeds like? (cents/MJ)
- feeds vary on season, rainfall
- cost per unit of energy or protein= to compare how much value you are getting in the feed
- have high energy feeds, or high protein
- forage ones= more expensive per unit of energy (lucerne= alfa alfa)
What are the energy concentrates?
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What do you look at when evaluating grain?
-look at: • Seeds are not split or cracked • Seeds are of low-moisture content • Seeds have a good colour • Free from mould • Free from rodent and insect damage • Free from foreign material • Free from rancid odour
What are maize distillers grains?
- grain by product, from making beer
- usually can get for free but have to beware of quality
- left: Low quality – poor toasting digestibility of crude protein reduced – high ADIN
- right: High quality high digestibility and low ADIN
What does a cereal grain look like?
-embryo: where the protein is, the rest is carbohydrates
What are the sugar refining by-products?
-Molasses (liquid) • By-product of sugar beets, sugarcane, citrus waste or wood products used to manufacture sugar • Very palatable and readily available energy source. Minimum content 46% sugar • Restricted to 2-5% of dry rations as a flavour/taste additive, binding agent, also controls dust • Levels approaching 8-10% may result in clumping of feeds in mixer or ingredients clumping together in sacked feed, increased risk of mould • Can be laxative at high levels • Inefficiency in utilisation can lead to high levels of methane production -all animals will eat sugar
What is betaine?
-by-product of sugar refining, osmolite= good for hangover, effects on lipid metabolism, protects agains heat stress -used for muscle growth and fat loss in the bodybuilding community
What are the feed blocks, licks and supplements?
-Until recently these supplements could just have water soluble ingredients, such as urea and molasses -Advances in technology now allows admixtures of most kinds of feeds. For instance we can now add dry supplements: soya, cottonseed, minerals, vitamins, additives -Delivery systems for feed additives: clay, xantham gum, xylan- based materials
What are some more energy by-product feeds?
• Dried Bakery Products • Similar to composition of wheat except for ether extract content (12-16%) • Limited in diets to 20% due to high salt content • Vegetable and fruit wastes • Unmarketable or damaged commodities • Crop residues left in the field • Canning,juicing,orprocessingwastes • Use is restricted to areas where processing locations are found -lot of byproducts from mass production of bread and very high in carbs, can be used in feeds -ether= fat content -have to be limited as have high salt! almost all processed food has high salt content
What about feeding oil and fat to animals?
-Residue remaining after extraction of oil from seeds is high in protein • Some heating is desirable for oil meals to destroy toxic/inhibitory compounds (e.g. lectins in soya oils) • Heating must be carefully controlled as to not reduce the digestibility of the proteins (heat damaged protein or ADIN)
How are fats and oils utilised in feeds?
• Used extensively in commercially prepared diets (1-7% in pelleted concentrate) to: • Increase energy content (GE of fat = 39 MJ/kg DM) • Controls dust • Improve pelleting rate (improves consistency of mixture as it enters the die) • Improve palatability (too much reduces palatability) • Reduce machinery wear • Should be treated with an antioxidant (e.g. BHT) to prevent rancidity (oxidation products)
What are the protein concentrates?
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