Nutrient Classes in Nature:
1. Protein
2. Carbohydrates
= simple = glucose; starch, fiber3. Lipids
= fats, glycerol backbone & 3 fatty acids most concentrated form of energy (4, 4, 9 kcal/g for protein, carbohydrates, and fats, respectively)4. Vitamins
= fat soluble A, D, E, K; H20 soluble B complex & C5. Minerals
= Macro and Micro6. Water
= often forgot cheapest to supply7. Oxygen
= not really a dietary nutrient
Proximate Analysis
used to evaluate nutritive content of feeds. Developed in 1860s at the Weende Experiment Station, Germany.1. Moisture
= 100 oC2. Ash
= Muffle furance burn 400-600 oC3. Kjeldahl N
= protein (6.25 X %N) Boil in H2SO4 distill ammonia4. Ether Extract
= Fat, boil in ether, distill fat left5. Crude Fiber
= acid/base hydrolysis boil in weak acid then weak base ® ~undigestible6. N Free Extract
= Calculated by difference, more readily available CHOsPlant Composition
Highly dependent upon function of the various parts.
Stem:
= structural Þ contains cellulose and lignin high CHO contentLeaves:
= photosynthesis Þ requires enzymes enzymes are proteins Þ leaves high in proteinSeeds:
Germination and reproduction Þ storage site of nutrientsHigh in protein and energy
Surrounding the seed is a tough cellulose fiber
®
grain sorghum (milo), corn, oats = crack, pop, roll, crimp, grind, etc. to increase digestibility1. Cereal Grains:
store energy as CHO (starch), corn wheat, barley2. Oil-bearing Seeds:
store energy as lipid (oil), soybean, cottonseed, penut
Animal Body Composition
Water:
Essential component of every cell
Blood = 90% |
Bone = 45% |
Muscle = 75% |
Enamel = 5% |
Fat:
All cell membranes are composed of phospholipidsAdipose tissue = energy storage site in the body
Protein:
Present in every cell of the body (membrane, enzyme, )Epithelial lining of the GI tract, respiratory system, urogenital, skin, hair, muscles, tendons (connective tissue)
Minerals:
Bones & teeth = |
Ca, P, Mg |
Tissues = |
S & P (ATP) |
Body Fluids = |
Na, K, Cl (electrolytes) |
Blood = |
Fe (hemoglobin) |
Carbohydrates:
<1% in animalsBlood ~ free glucose
Muscle and liver = glycogen (animal starch)
Comparative Digestive Physiology
Meat Cut |
Species |
Composition |
Diet |
Digestion |
Pork Chop |
Pig |
80% Protein 20% Ash |
Corn (Starch) |
Hydrolytic |
Ribeye Steak |
Steer |
80% Protein 20% Ash |
Grass (Cellulose) |
Fermentive & Hydrolytic |
Steer can eat grass and produce meat products but pig can not
® because of digestion! Type of feed is determined by type of digestion.Gastrointestinal, GI, Digestive, Alimentary, Gut = all the same thing
Two Types of Digestion
1. Hydrolytic:
All digestive enzymes secreted by animal tissueOccurs?
= stomach, intestine, pancreas (secretes enzymes)Species?
= All are dependant on this type of digestion2. Fermentive:
Enzymes are of microbial origin (primarily bacteria & protozoa)Occurs?
Rumen, Cecum – these two "organs" contain a viable microbial population. **Microbes secrete the enzymes NOT the organs.Species?
Herbivores – Cows, sheep, horses, etc.