VET 110-601 Nutrition and Principles of Feeding

1
VET 110-601Nutrition and Principles of Feeding

• Nutrient Functions and Requirements

2
Feeding Standards

• Based on nutrient requirements
• Species specific
• Physiological state specific
• National Research Council (NRC)
• Current feeding standards for each species
• Guideline

3
Nutrient Requirement

• Total amount of that nutrient required for all
  physiological functions
• Deficiency or excess detrimental
• Expression
• Total amount required per day
• Concentration required in the diet

4
Nutrient Requirement

• Animals require a specific amount of a specific
  nutrient
• Ad Lib diets formulated based on nutrient
  concentration
• Needed accurate estimation of intake
• Example
• Animal requires 150 g of nutrient Z / day
• Animals estimated daily intake is 10 kg / day
• Concentration of Z in diet should be 15 g / kg
  (1.5)

5
Nutrient Functions

• Maintenance
• Animal neither gains nor loses nutrients
• Initial reference point additional requirements
  added depending on physiological state
• Growth and Development
• Measured as total or changed weight
• Growth rates weight change / time
• Growth curves

6
Growth Development - Growth Curve
Growth curve of an animal with mature weight of
500 kg (1100 lbs)
7
Growth Development - Growth Rate

• Lowest following maturity
• Intermediate from puberty to maturity
• Greatest from birth to puberty
• Young greatest nutrient requirement / kg BW
• Diet high quantity and quality of nutrients
• Economics is important!!!
• Gross efficiency is greater in young
• Is maximum growth rate required?
• Is a lower growth rate more economic?

8
Nutrient Functions

• Lactation
• Nutrient requirements function of production
• Higher production higher requirement
• Production varies among within species
• Milk Nutrients water, lactose, lipids, protein,
  and minerals especially Ca and P
• Nutrient Sources
• Diet
• Tissue mobilization

9
Nutrient Functions - Lactation
In early lactation, a lactating cow cannot
fulfill her nutrient requirements from the diet
and will metabolize body tissues resulting in the
decrease in body condition. As illustrated by the
increase in body condition later in the
lactation, the animal must replenish body
reserves for the subsequent lactation.
10
Nutrient Functions

• Reproduction
• Prior to breeding
• Nutrient balance affects conception and pregnancy
  
• Initial two-thirds of gestation
• Final one-third of gestation
• Greatest requirement
• Fetal tissue growth
• Increased dams metabolic rate

11
Nutrient Functions

• Work
• Required nutrients
• Water
• Carbohydrates
• Proteins
• Vitamins
• Minerals
• Greater work greater requirement

12

• Estimating Nutritive Value

13
Nutritive Value

• Estimate of nutritional quantity and quality
• Species and physiological state dependent
• Components
• Nutrient content
• Efficiency of nutrient use
• Antinutritional factors
• Methods
• Laboratory-based analyses
• Animal-based analyses
• Additional considerations

14
Lab Based Analysis

• Objective
• Measure amount of each component (nutrient) in
  feedstuff
• Accurate quantitative measurement
• Quantity, not quality
• Procedures
• Proximate analysis
• Detergent Fiber System
• Gross Energy
• Special Procedures

15
Lab Based procedures Proximal Analysis
16
Proximal Analysis

• Dry Matter
• Estimates free water content in sample
• Weighed sample placed in an 105 C oven for 12
  16 h
• Sample reweighed
• Loss in weight is moisture content

17
Proximal Analysis

• Crude Protein
• Amount of protein and NPN compounds in feed
• Measured using Kjeldahl procedure
• Dry sample boiled with sulfuric acid, diluted
  with water, neutralized with Na hydroxyde
• Sample is distilled and the distilled ammonium is
  titrated with sulfuric acid
• The N concentration found, multiplied by 6.25
  CP
• Errors
• Not all N is protein
• Not all proteins have 16 N

18
Proximal Analysis

• Ether extract (EE)
• Estimates quantity of organic solubles lipids
• Dried sample is ground and weighed and extracted
  with boiling ether for 4 hours
• Solvent residue is dried and weighed ether
  extract or lipid weight
• Error
• Not all materials soluble in ether are lipids

19
Proximal Analysis

• Crude Fiber
• Estimates quantity of fibrous CHO in food
• Simulates pH related processes in GIT
• Procedure
• Sample boiled in sulfuric acid for 30 min and
  rinsed
• Boiled in Na hydroxide for 30 min and rinsed
• Residue is dried and weighed (W1)
• Residue is ashed and re-weighed (W2)
• Crude fiber W1 W2
• Many errors

20
Proximal Analysis

• Ash
• Estimates quantity of minerals
• Weighed sample is heated at 500 600 C for 2 - 4
  hours
• Remaining residue weighed ash

21
Proximal Analysis

• NFE
• Estimates non fibrous CHO content
• NFE 100 ( EE CP Ash CF).

22
Lab Based Procedures Detergent Fiber System
23
Lab Based Procedures Detergent Fiber System

• More accurately estimates CHO fractions
• Estimates of fibrous CHO
• Neutral detergent fiber (NDF)
• Sample boiled in ND solution for 1 hour
• Extracts Cell wall contents digestible
  fraction
• Residues NDF hemicellulose, cellulose, lignin
• Acid detergent fiber (ADF)
• NDF residue boiled in sulfuric acid solution
• Residue ADF cellulose and lignin

24
Lab Based Procedures Detergent Fiber System

• Estimates of nonfibrous CHO
• Nonfibrous carbohydrates (NFC)
• Calculated
• NFC 100 ( EE CP Ash NDF).

25
Lab Based procedures - Gross Energy

1. Weighed sample and O2 added to chamber
2. Sample is completely oxidized
3. Change in water temperature is measured
4. GE amount of heat produced

26
Lab Based Procedures - Other

1. High Performance Liquid Chromatography
2. Atomic Absorption Spectrophotometry
3. Near Infrared Reflectance Spectroscopy
4. Gas Liquid Chromatography

27
Nutrient Evaluation Animal Based

• Objective Measure utilization efficiency of each
  component in a feedstuff
• Used in conjunction with laboratory-based
  analyses
• Feeding trials
• Digestion trials
• Balance Trials

28
Animal Based Analysis Feeding Trials

1. Compare production results between feeding
   schemes
2. Applied research simulate production environment
   
3. Usually preliminary trials, followed by digestion
   and balance trials
4. Designed with Control and treatment(s)
5. Measure production differences

29
Animal Based Analysis Digestion Trials

• Estimate total amount of specific nutrient
  absorbed from GI tract
• Two measures
• Apparent digestibility
• Does not account for endogenous sources
• Generally, digestibility measured
• True digestibility
• Does account for endogenous sources intestinal
  cells, enzymes, microbes

30
Animal Based Analysis Digestion Trials

• Procedure
• Determine feed intake and nutrient concentration
  in feed
• Determine amount of feces excreted and nutrient
  concentration in feces
• Calculate intake and excretion on a DM basis
• digestibility () ((nutrient in nutrient out)
  / (nutrient in)) x 100.

31
Animal Based Analysis Balance Trials

• Estimate net retention of specific nutrient
• More complete picture of a nutrients utilization
• Procedure
• Determine nutrient intake, nutrient output
• Output via feces, urine, respired air, and
  sloughed materials (sking, hair, feathers)
• Require using metabolism crate
• Require adaptation and sampling period

32
Digestibility
33
Balance
34

• Gastro Intestinal Tract and Nutrient Utilization

35
GI TRACT

• Series of external organs
• Species specific
• GITs anatomy physiology determine what feeds
  to feed to an animal and how efficiently
  nutrients are used
• Primary functions
• Digestion
• Conversion of complex compounds in feed into
  simple absorbable compounds
• Absorption
• Process in which simple compounds cross the
  cellular membranes of the GI tract into the blood
  or lymph system and are transported to the tissues

36
GIT CLASSIFICATION

• Digestive anatomy and physiology
• Simple nonruminants (monogastrics)
• One chamber stomachs
• Ruminants
• Complex 4 chamber stomach
• Type of diet consumed and utilized
• Herbivores consume plant tissue
• Carnivores consume animal tissue
• Omnivores consume both

37
Classes of GIT
38
Non Ruminant omnivore
Relatively small cecum
39
Non ruminant omnivore
Avian GIT has unique features. Note crop,
proventriculum, gizzard and cecum
40
Non ruminant herbivore
The relatively large cecum allows the horse to
consume and digest high fiber feedstuffs
41
Ruminant Herbivore
Ruminant GIT have unique characteristics. Note
the 4 stomach chambers
42
GIT and Nutrient Utilization - Mouth

• Mouth, tongue teeth
• Functions
• Prehension different among species
• Mastication different among species. Dogs have
  more molars than cats and can use plant material
  better
• Saliva
• Added during mastication
• Functions
• Aids bolus formation
• Coats bolus
• Moistens feed
• Provides enzymes
• Acts as buffer (Na bicarbonate for ruminants)

43
GIT and Nutrient Utilization - Esophagus

• Tube from mouth to stomach or reticulorumen
• Functions
• Transports bolus via muscular contractions
• In nonruminants downward
• In ruminants downward and upward (rumination)

44
GIT and Nutrient Utilization Glandular Stomach

• Functions
• Storage
• Mixing with gastric secretions peristalsis
• Initial protein digestion pepsin
• Bactericidal via hydrochloric acid (HCl)
• Regulates passage of food into Small Int.
• Cumulative activities produce chyme (partially
  digested acidic mix of feed)

45
GIT and Nutrient Utilization Small Intestine

• Primary site for enzymatic digestion.
• Duodenum
• Bile salts produced by liver and stored in
  gallbladder neutralize chyme and emulsify fats
• Pancreatic enzymes digest proteins, CHO and
  lipids
• Additional duodenal enzymes for proteins and CHO
• Jejunum and Ileum
• Enzymatic digestion continues

46
GIT and Nutrient Utilization Small Intestine

• Small Intestine Primary absorption site
• Interior lined with villi and microvilli
• Increase surface area and absorption efficiency

47
GIT and Nutrient Utilization Large Intestine

• Three regions
• Cecum
• Colon
• Rectum
• Functions of cecum and colon
• Absorption of some organic compounds
• Absorption and reabsorption of water
• Primary digestion microbial digestion
• Rectum excretion of waste matter

48
GIT Nutrient Utilization - Avians

• Mouth no teeth
• Stomach has 3 regions
• Crop
• Temporary storage
• Proventriculus
• Glandular stomach
• Gizzard
• Dense pouch
• Tough, muscular lining
• Has grit
• Grinds feedstuff
• Two large ceca
• Combined urine and feces

49
GIT Nutrient Utilization - Ruminants
50
Reticulum

1. Honeycomb surface
2. Capture and retain dense particles
3. Microbial fermentation

51
Rumen

• Largest compartment
• Extensive pre-digestive and pre-absorptive
  microbial fermentation
• Bacteria, protozoa, and fungi
• Population is diet and intake dependent
• Lined with papillae
• Increases surface area and absorption

52
Omasum

1. Membranous leaves in lumen
2. Sieve large particles regulates food passage to
   abomasum
3. Water reabsorption

53
Abomasum

• Glandular stomach
• Largest compartment prior to rumen development

54
Unique characteristics of ruminants

• Young ruminants have no functional rumen they
  have reticular or esophageal groove
• Milk directly from esophagus to omasum
• Rumen development
• Stimulated by volatile fatty acids (VFA)
• Lambs 8 weeks
• Calves 6 to 9 months
• Rumination
• Regurgitation and remastication
• Eructation
• Emission of fermentation gases

55
Rumen fermentation

• Advantages
• Efficient utilization of fibrous feedstuffs
• Rumen microbes metabolize Hemicellulose and
  cellulose to VFA (acetate, propionate, butyrate).
  VFAs are used for energy.
• Efficient utilization of lower quality protein
  and NPN
• Conversion to higher quality microbial protein
  digested in the abomasum
• Production of water-soluble vitamins and vitamin
  K

56
Rumen fermentation

• Disadvantages
• Reduced utilization efficiency with higher
  quality feeds
• Reduced yield from digestible energy sources
• High converted to lower quality protein