W3 lab quiz

Question 1

main feedstuffs classifications

Answer 1

1. forages/roughages
2. concentrates
3. supplements
4. additives

Question 2

forages/roughages

Answer 2

• plant materials that are:
  
  • high in fiber (>18% crude fiber)
  • low in energy
  • bulky
  • variable in protein content
• fed to ruminants & hind-gut fermenters

Question 3

forages

Answer 3

vegetable material in a fresh, dried, or ensiled state

• fresh = living plant material above the ground
  
  • quality depends on: rainfall, stage of maturity, soil fertility, & level of grazing
  • high in moisture (up to 85%)
  • e.g. mixed-grass pastures grazed by ruminants & horses
• dry → can be transported & stored for a long time
  
  • e.g. alfalafa hay, timothy hay, oat hay
• ensiled = fermented forage (pickled) → can be preserved for a long time
  
  • made from high-moisture crops that have been chopped, compacted, & stored in airtight containers & preserved by acids produced during fermentation
  • e.g. corn silage, wheat silage, barley silage, alfalfa silage

Question 4

roughages

Answer 4

harvest/crop residues

• material left over in the field after harvesting the main crop
• contain high fiber content & lower quality that forages
• e.g. corn stalks, corn stover, wheat straw, oat straw

Question 5

concentrates

Answer 5

• feedstuffs high in starch, sugars, or fats
• high digestibility
• low in crude fiber (<18%)
• can be utilized by ruminants & non-ruminants
• energy concentrates = feedstuffs that are used for high-energy content
  - TDN >70%
  
  • <20% crude protein
  • e.g. gains (corn, barley, wheat, milo), molasses, fat supplements (plant oils & animal fats), some milling byproducts (wheat middlings, hominy feed)
• protein concentrates = high in energy (>70% TDN) but mainly fed for high protein content (>20% crude protein)
  
  • e.g. plant origin: oilseed meal, soybean meal, cottonseed meal, sunflower seed meal, peanuts (oil removed)
  • e.g. animal protein sources: meat & bone meal, blood meal, fish meal, poultry litter, feather meal, whey
  • synthetic protein (e.g. urea)

Question 6

TDN

Answer 6

total digestible nutrients = estimate of amount of energy available for catabolism by animal

Question 7

supplements

Answer 7

• aka premixes
• ensure animal’s vitamin & mineral needs are met
• mineral supplements are limited to 1-2% of a balanced diet
  
  • macro = NaCl, P, Ca, Mg, S
  • micro = Cu, Fe, I, Zi, Co
  • e.g. synthetic or natural (oyster shell, bone meal, limestone)
• vitamin supplements limited to 1% of diet (expensive ∴ not widely used)

Question 8

feed additives

Answer 8

• do not supply nutrients
• small quantities
• fxns:
  
  1. to improve rate &/or efficiency of weight gain
  2. prevent diseases
  3. preserve feeds
  4. enhance ration flavor to maintain consumption
• e.g. buffers, antioxidants, antibiotics, or flavorings

Question 9

miscellaneous feedstuffs

Answer 9

• sometimes a feedstuff does not belong to a specific category or belongs to more than 1 simultaneously
• plant-based byproducts from ag/food production = relative high in fiber ∴ for ruminants or hind-gut fermenters
• e.g. whole cottonseed, almond hulls, citrus pulp, cottonseed hulls, soy hulls, wheat bran, beet pulp

Question 10

feedstuff processing

Answer 10

• common for grains
• improves digestibility of grains by ↓ particle size or ↑ SA open & available to digestive enzymes or fermentation microbes
• cold-processing
  
  1. grinding: feed is battered to dust
  2. rolling: grain is flattened to crack open
• thermal processing → steam flaking/rolling: heat gelatinizes starch in grains which is then processed into a flake form ∴ more digestible

Question 11

feedstuff mixing

Answer 11

• adequate mixing ensures all animals receive uniform ration
• feed mills
  
  • can mix large quantities at once
  • accurate scales weigh as added ∴ can add small quantities of minerals/supplements
  • cannot handle bulky feed (hay or wet feeds)
  • useful for dry mix feeds for non-ruminants
  • not useful for complete ruminant rations
• rations for ruminants are mixed on the farm by large mixer wagons designed for wet/bulky ingredients
  
  • do not hav accurate scales
  • can only mix large quantities
  • premixes of minerals/supplements added
• large commercial dairies mix TMR daily from scratch immediately before feeding (sometimes premix of dry ingredients is mixed the day before for efficiency)

Question 12

total mixed rations

Answer 12

TMR = total mixture of all feedstuffs in proper proportions

1. long hay in first
2. add grains/premixes
3. follow w/ small-quantity ingredients
4. forages that do not need processing (should be properly mixed before adding wetter ingredients)
5. liquid feedstuffs

Question 13

types of mixers

Answer 13

• vertical mixer
  
  • bulky feed first, then heavier/dense ingredients, then liquid
  • simple design → less mechanical error
  • more consistent in quality of mix
• horizontal mixer
  
  • does not require feed to be added in any particular order
  • more complex machinery
  • easy to overfill → can cause mechanical damage
  • feedstuffs need to be right size (not too large/small)
  • requires processing of roughage