nutrients

Question 1

nutrient partitioning

Answer 1

process by which the animal subconsciously designates fuel for use

maintenance: understand species-specific needs to meet basic metabolic fx

growth: good quality food to ↑ growth ➔ ↑ weight gain & tissue

production: milk, meat, eggs, wool, etc.

reproduction: on top of maintenance & production to support continuity of human needs

Question 2

essential vs non-essential nutrients

Answer 2

essential must be obtained from diet
* body cannot make or cannot make in sufficient amounts to support needs

non-essential can be synthesized in the animal

Question 3

core nutrients

Answer 3

1. water
2. proteins
3. fats
4. carbs
5. minerals
6. vitamins

Question 4

water

Answer 4

• most important
• major constituent of body tissues & products (i.e. milk, eggs)
• required for all body fxs
• can drink or get from moisture in food
  
  • moisture in food ranges from 10-80% by weight
  • metabolic water produced as byproduct of metabolism

Question 5

carbs

Answer 5

• monosaccharides: glucose, fructose, galactose
• disaccharides: maltose, lactose
• polysaccharides
  
  • starch = food reserve for plants (⍺-linked)
    
    • grains
    • easily digested by any animal
    • bond can be broken down by digestive enzymes
    • amylase breaks down
    • glycogen = animal food storage
  • cellulose = plant material; structural component of plants (β-linked)
    
    • forage
    • very hard to break down
    • microbial fermentation required to digest
      
      • rumen of ruminants
      • cecum of horse
• contain C, H, & O
• ready source of energy
• organic

Question 6

fats

Answer 6

• triglycerides = glycerol + 3 fatty acids ➞ majority of fats
• used for:
  
  • energy reserve
  • insulation ➔ temp regulation
  • cell membranes
• fatty acid side chain can vary greatly in length
• organic but less O than carbs
• contain 2.25x more energy than carbs ➔ more dense
• carry fat-soluble vitamins ➔ vit D
• some are essential
• saturated have no double bonds = fats
• unsaturated have 1+ double bond = oil

Question 7

proteins

Answer 7

• made of AA that contain C, H, N, & O
• protein in feed has ~16% N
• simple protein just AA
• complex proteins = AA + other substances
  
  • heme groups ➔ hemoglobin
  • lipids ➔ lipoproteins
  • carbs ➔ glycoproteins

Question 8

minerals

Answer 8

• do not supply energy
• inorganic ➔ all elements other than C, H, O, & N
• micronutrients = required in small amounts (ex: Se)
• macronutrients = required in large amounts (ex:. Ca, P for bone)
• form essential components of complex proteins (ex: Fe in hemoglobin) ➞ cofactors

Question 9

vitamins

Answer 9

• do not supply energy
• catalysts for enzymatic fxs
• organic compounds
• required in trace amounts for specific fxs
• 16 known vit:
  
  • fat-soluble: A, D, E, & K ➔ essential for all animals ∴ must be supplied in all nutrients
  • water-soluble: C, B-vit, niacin, folic acid
    
    • essential for monogastric animals
    • non-essential for ruminants or hind-gut fermenters ➔ can be synthesized by bacteria
• lack of specific vit can cause disease

Question 10

core nutrients required for energy

Answer 10

• water
• carbs
• fats
• proteins
  
  • proteins = last choice for energy

Question 11

core nutrients required for structure

Answer 11

• fats
• proteins
• minerals
• water

Question 12

core nutrients for regulatory fxs

Answer 12

• proteins
• minerals
• water
• vitamins

Question 13

formulating domestic animal diets

Answer 13

must consider:
* digestibility: how easy an animal can break down feed & absorb its nutrients
* palatability: taste ➔ will the animal eat it

prepare based on:
1. what’s in the diet
2. how it’s broken down
3. how it tastes

Question 14

analysis of feed components

Answer 14

• same food can vary in nutrients depending on where it is grown/what envir it grows in

1. proximate analysis: system to figure out how much of each core nutrient is present in feed
2. chemical analysis: for exact mineral/elemental breakdown
   
   • uncommon
   • expensive

Question 15

proximate analysis

Answer 15

• analytical procedures done to feed designed to break out each nutrient of diet
• giving an approximation of how much of each nutrient in present
• trying to partition feed into each nutrient class
• separate feed into 6 diff samples: 1 for each core nutrient
  
  1. water content vs dry matter: weigh ➞ dry ➞ weigh again: difference = amount of water in feed
  2. inorganic components vs organic: incinerate ➞ ash = everything not organic = mineral content in feed
  3. proteins vs non-nitrogenous matter: Kjeldahl procedure: measures amount of N in sample x 16% = amount of N
  4. fat vs carbs: ether rxn
  5. fiber vs nitrogen-free extract: acid hydrolysis ➞ feed that survives = cellulose (crude fiber)
• subtract all other values from 100 ➞ left over = N-free component of diet

Question 16

DM

Answer 16

dry matter: weigh product ➔ dehydrate in oven ➔ reweigh

Question 17

pH levels: concentrate vs forage

Answer 17

concentrate = ↓ pH (acidic)
forage = ↑ pH