INTRODUCTION

1
 INTRODUCTION

•  Feeds represent the most expensive input cost
  for the livestock producer
•   
• Expensive to maintain the animal
•  
• Expensive if don't supply nutrient in adequate
  amounts to get good performance
•  
• Expensive if overfeed nutrients relative to the
  animal's requirements
•  

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 INTRODUCTION

•  Basic nutrients
• Water
• Protein
• Energy fat and carbohydrates
• Minerals macro and micro
• Vitamins fat soluble and water soluble

3
 INTRODUCTION

•  Important to understand most limiting nutrient
  concept
• Animal performance
• Balance
• Cost

4
Feeds and ration formation involves applications
of the process of nutrient utilization  

• Ingestion
• prehension of feed, chewing and swallowing to the
  initial digestive organs
•  Digestion
• reduction of food to utilizable form physical
  and chemical processing of ingested food
• Absorption
• food is reduced to utilizable form transported
  from inside the digestive tract to the blood
  stream
• active transport
• passive diffusion
• Metabolism

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 Biological Functions that Require Nutrients

•   Maintenance "the maintaining of an animal in
  a state of well being or good health from day to
  day".
• A maintenance ration is the feed required to
  adequately support an animal doing no non-vital
  work, making no growth, developing no fetus,
  storing no fat or yielding no product.
•  
• As much as 100 of an animals ration

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 Maintenance

•  Energy for vital functions heart, respiratory,
  membrane transport
• energy expenditure gives off heat
• Maintain body temperature
• sources heat from work of vital organs, heat
  from nutrient utilization, heat from work of
  normal activity, heat from economic work, heat
  from work of shivering

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 Maintenance

•  Protein for repair of tissue
• there is constant breakdown or turnover of body
  tissue protein
• excreted largely as urine
• N excreted as urine during starvation equals
  maintenance requirement for protein
• Minerals some minerals excreted daily (not a
  problem)
• Vitamins
• Others water, small amount of fats

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 Growth increase in muscle, bone, and
connective tissue (accumulation of fat is not
growth)

• Protein -- dry matter of muscle and connective
  tissue
• Energy
• Minerals -- especially calcium and phosphorus in
  young
• Vitamins
• Water -- free muscle tissue is about 75-80 water

9
 Fattening

• Deposition of unused energy in the form of fat
• Internal fat (around abdominal organs),
  intermuscular, subcutaneous
• Intramuscular fat
• Fattening versus growth growth is easier to
  deposit
• muscle is mostly water
• fat may actually replace water
• 2.25 x's amount of energy in fat versus protein
  or carbohydrate
• nature of the growth curve for all animals

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Changes in body composition with increased age
and weight of pigs
age (days) weight (kg)
1 1-2
17 2-2
28 7
89 25
age (days) weight (kg)
144 60
183 90
200 110
water
fat
protein
ash
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Normal postnatal growth curves of bone, muscle,
and fat.
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 Reproductive animals

• Milk production
• nutrient requirements are in proportion to amount
  of milk produced
• Major nutrients required are energy, protein, Ca
  and P
• Fetal development
• fetal requirement for nutrients is not great
• 83 lb calf (25 DM) 22 lb of DM which is only
  about 4 days of milk for the lactating animal
• importance of nutrition during late gestation may
  be preparation for lactation (and rebreeding in
  cattle)
• Others wool, work, others

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Nutrients from a Feed Management Perspective
(Chapter 3, Kellems and Church)

•  Water
• Water - most crucial nutrient -- most immediately
  required
• 70 of lean body mass
• Can only lose 10 of body water
• Consume 3-4 times amount of water as dry matter
  (DM)
• Consume an amount of water which is needed to
  maintain homeostasis (GIT, blood)

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Water

•  Functions
• transport (digesta, blood)
• urine -- media to excrete nitrogenous waste
• evaporative cooling
• rumen microbes
• Sources
• drinking water
• feed -- some feeds have up to 85 water
• metabolic water -- oxidation of nutrients to
  produce water

15
Water

•  Practical Applications
• water consumption is critical to maintain DM
  (nutrient) intake
• requires management during hot and cold weather
• requires management when high salt diets are fed

16
Energy

• Energy is very difficult to measure
  quantitatively
• defined as calories -- amount of energy required
  to raise 1 g of water 1o C -- kilocalorie
  megacalorie
• Carbohydrate CHO 121
• C6H12O6 6 O2 6 CO2 6 H2O

17
Energy - Carbohydrates

•  Monosaccharides
• Glucose -- primary sugar
• Fructose -- ketose, sweet, corn sweeteners
• Galactose
• Mannose
• Arabinose
• Xylose
• Ribose

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Energy Carbohydrates - Polysaccharides

•  Nonstructural carbohydrate (NSC) or non-fiber
  carbohydrate (NFC) mostly starch (some simple
  sugars), very extensively digested and/or
  fermented (90 percent), not bulky
• Amylose
• Amylopectin waxy grains, probably more
  extensively fermented ruminally
• Glycogen animal energy storage liver and
  skeletal muscle

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Structure of starch Amylopectin, showing 16
branch point.
6
6
6
6
CH2OH
CH2OH
CH2
CH2OH
O
O
O
4
4
4
1
1
1
4
1
O
O
O
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Energy Carbohydrates - Polysaccharides

•  Structural carbohydrate fiber less
  digestible even in the ruminant, very bulky -
  occupies much space in the GIT
• cellulose primary carbohydrate in fiber,
  comprised solely of ?-1,4 linked glucose, lowly
  digestible
• hemicellulose secondary carbohydrate in fiber
  made up of glucose, xylose, arabinose, mannose,
  galactose
• lignin -- most significant anti-nutritional
  factor
• amorphous polyphenols
• gives support to the cell wall structure
• present in the "woody" plant parts
• increase as plant matures

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Energy Carbohydrates Other Polymers

•  Pectin -- plant cell wall cement
• Cutin - waxy coat of leaf surface

23
Diagram of a plant cell showing cell wall
structure
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Energy Structural Carbohydrates

• Chemical treatment - objective is to make the SC
  fraction of forage more digestible
• Ammoniation anhydrous, aqua or urea
• Untreated straw ? 42 digestible
• Ammoniated straw ? 55 digestible
• Effectiveness depends on conditions during
  treatment
• Alkaline hydrogen peroxide oxidizes the lignin

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Daily feed cost for 1200 lb, late gestation cow
Conventional, hay alone 1.15/day

• Ammoniated bluegrass straw
• Straw 21.7 lb
• Barley 1.5 lb
• Alfalfa 1.0
• /day .75, or
• Instead of 18, could afford 24/ton) treatment
  cost

• Untreated bluegrass straw
• Straw 15.5 lb
• Barley 3.0 lb
• Alfalfa hay 8.4 lb
• /day .82

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Ruminant system of carbohydrate digestion and
absorption
Polysaccharide simple sugar absorbed 6
ME   or   Polysaccharide simple sugar
fermented to VFA absorbed ME  
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Ruminant system of carbohydrate digestion and
absorption
 
 
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Ruminant system of carbohydrate digestion and
absorption

• Propionic acid most energy efficient VFA
• Propionic acid increased by
• Feeding higher level of grain
• Feeding ionophores
• Ionophores (Rumensin and Bovatec)
• Acetic acid, ? propionic acid, no change in total
  VFA
• Feedgain
• Methane production, ? bloat

 
 
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Ruminant system of carbohydrate digestion and
absorption Effect of feeding grain
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Ruminant system of carbohydrate digestion and
absorption Effect of feeding grain
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Ruminant system of carbohydrate digestion and
absorption Effect of feeding grain

• Acidosis symptoms
• variable feed intake (symptom and cause)
• feces loose splattering, less than 1 high,
  no dimpling/concentric rings
• lack of cud chewing
• hoof lines, abnormal hoof growth
• dairy milk fat inversion
• beef liver abscesses

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Acidosis

• Indicates rumen insult
• Grows .25 inch (6 mm) / month

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Liver Abscess Classification
A -
O
A
A
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Energy Lipids

• fat glycerol fatty acids
• triglyceride glycerol 3 fatty acids
• fatty acid length -- C14 to C20
• very hydrogenated energy
• saturated vs unsaturated
• essential fats
• linoleic C18-2
• linolenic C18-3
• arachidonic C20-4

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Energy Lipids

• Feed applications
• fats contain 2.25 x's energy per weight as CHO's
  -- CHO 4 kcal/g fat 9 kcal/g
• increase the energy density of a ration must be
  limited, usually 5-6 of ration as lipid for
  ruminant, 6-7 for monogastric
• reduce dustiness
• may increase palatability
• aid absorption of vitamin A,D,E,K
• may decrease absorption of Ca, Mg, Na

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Energy Lipids

• Feed applications continue
• fat will reduce fiber digestion in the rumen
  commonly seen in the lactating dairy cow
  restrict fat to about 6 percent of the total diet
  DM
• now have ruminally inert fats on the market to
  avoid lower fiber digestion best to have a
  combination of fat from basal ingredients, an oil
  source such as whole cottonseed or full fat
  canola, and inert fat
• fat metabolism -- ketones -- ketosis

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Protein

• Most expensive nutrient per weight to supply
• Functions
• Muscle
• Enzymes
• Hormones
• Antibiotics
• skin, hair
• Amino acids are what is actually required by the
  animal -- building blocks of protein

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Protein

• Protein ? digestion ? free AA ? absorption ?
  transported to the cell to synthesize a new
  protein for use by the animal
• Animal can not absorb an intact protein
• 21 naturally occurring AA
• 10 essential AA

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Protein

• Dietary Essential AA -- an amino acid required by
  an animal and can not be synthesized by the
  animal in the amounts needed and therefore must
  be present and available in the diet
• Arginine
• Histidine
• Isoleucine
• Leucine
• Lysine
• Methionine S-containing, Cystine may provide ½
  the reqmt
• Phenylalanine -- tyrosine may provide ½ of the
  requirement
• Threonine
• Tryptophan
• Valine
• Nonessential AA -- required by the animal but can
  be produced in adequate amounts
• Limiting AA -- AA that is first depleted during
  protein synthesis

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Ruminant system of protein digestion and
absorption

• dietary AA are not the same AA that are
  absorbed and used to synthesize animal protein

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Summary -- Advantages of the ruminant
system   º utilize fibrous feeds º utili
ze NPN   º B vitamin production (plus vitamin K)
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Minerals

• Macro mineral (Ca, P, K, Na, Cl, S, Mg)
• versus
• Micro mineral ( Fe, Co, Cu, F, I, Mn, Mo, Se, Zn)
• sulfates more bioavailable than oxides
• chelated (or proteonated) minerals (Zn, Mn, Cu,
  Fe, Se) may be beneficial, but are much more
  expensive
• Most recent is FDA approval of Se-methionine
• Cu, Se, Zn and Fe are now recognized to be
  important factors in immune function
•  
• Ca, P and Mg needed in greatest abundance and
  most commonly supplemented

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Minerals
A.              Sources Ca P
  1.   Oyster shell 38 2    Ground
limestone 36 3.   Defluorinated rock
phosphate 33 18 4.   Dicalcium
phosphate 23.4 18.7 5.   Mono-ammonium
phosphate 26.9 (12.2 N) 6.   Mono-sodium
phosphate 22.4   7.   Forages .3-2 .15-.4
8.   Grain lt.05 .3-.4 9.   Requirement
.3 to .4 .25    CaP ratio 1.2 to 1.51 for
growing animals and dairy 61 laying hens
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Minerals

• Phytate phosphorus
• Form of P bound in phytic acid, most P in grains
  is in phytate form
• This form of P is lowly available for
  monogastrics but is available for ruminants
• Interest in phytase to increase utilization of P
  in basal ingredients - both endogenous and
  exogenous phytase

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Minerals

• Magnesium -- hypomagnesemia -- grass tetany
• occurs during cool season, low root uptake of Mg
• or if dietary Ca is too high
• or when high soil (forage) K
• or low soil P
• desire K(Mg Ca) lt 2.3 in grazed forage
• supplement with MgO, MgSO4, legumes
• Selenium -- Se deficient soils
• FDA will now allow supplemental Se at .3 ppm
  seems to be level we need for of Se-deficient
  soils

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Minerals

• Copper - - deficiency of grazing animals
  throughout the western states probably more
  associated with Mo antagonism
• Want a CuMo ratio in vegetation greater than 7
• Potassium -- supplement stressed animals
• Rest of the minerals are adequately supplied in
  TM salt mixes --almost exclusively

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Vitamins

• Fat (A, D, E, K) vs water (B vitamins, C)
  solubles
• Monogastrics require supplemental water and fat
  soluble vitamins A,D,E, riboflavin, thiamine,
  niacin, pantothenic acid, and B12 are commonly
  provided in commercial vitamin premixes.
• Ruminants have a reduced need for dietary supply
  of vitamins vitamin A is most commonly
  supplemented, no need for water solubles or
  vitamin D if outside
• Supplementation of D and E are becoming more
  common recognize that young animals and
  ruminants without green forage may respond to
  vitamin E supplementation involved in immunity
  injection or feed