Nutrition

1
Nutrition

• Nutrition
• provide animals with nutrients to enable them to
• maintain grow
• reproduce lay eggs
• lactate produce wool
• work
• PROFIT feed animals adequately economically
• first must understand process of digestion and
  absorption of nutrients from feeds

2
Animal Classification By Type of Food Consumed

• Herbivore - Depends entirely on plant food
• - Sheep, Cattle, Horses
• Carnivore Almost entirely on meat for food
• - Dog
• Omnivore Both meat and plants for food
• - Swine, Chickens, Humans

3
Animal Classification By Type Digestive System

• Major differences in anatomy and physiology of
  digestive tracts of different species
• Affects nature of digestive processes and the
  kind of feed that can be utilized by the animal
• Based upon type of digestive tract, 4 different
  classifications can be made.

4
Animal Classification By Type Digestive System

• Monogastrics Major Category
• 1. Simple Stomach Pigs, Humans, Dogs
• 2. Avian Chickens, Turkeys
• 3. Pseudo Ruminants Horses, Rabbits
• Ruminants Cattle, Sheep, Goats

5

• Swine - Simple stomach, Limited
  capacity -Chemical secretions and enzymes are
  critical for digestion -limited
  microbial action, limited fiber digestion

Figure 63  Swine digestive tract.
6
Digestive System Parts and Functions - Swine

• Mouth Initial breakdown of food, mechanical,
  amylase in saliva, some lipase
• Stomach Initial digestion of food, broken to
  smaller particles
• Hydrochloric acid HCl, breaking of bonds
• Pepsin proteins to polypeptides

7
Digestive System Parts and Functions - Swine

• Small Intestine Further breakdown and
  absorption of food
• Pancreatic Enzymes
• -Lipase - fats to fatty acids and glycerol
• -Trypsin - polypeptides to peptides
• -Chymotrypsin peptides to amino acids
• -Amylase starch to disaccharides
• -Sucrase, Maltase, etc. disaccharides to
  monosaccharides
• Reduced particles are absorbed into the
  bloodstream across wall of the small intestine.
  Diffusion passive, Transport active.

8
Digestive System Parts and Functions - Swine

• Cecum/Large Intestine limited plant fiber
  digestion
• -microbes present produce the enzyme cellulase
• -cellulase breaks down cellulose (one type of
  plant fiber)
• -very inefficient system in monogastrics (except
  horses)

9

• Avian monogastric, similar to others except
• different anatomy since no teeth to chew food
• -Limited capacity
• Chemical secretions and enzymes are critical for
  digestion
• Limited microbial action
• Limited fiber digestion

Figure 67  Digestive system of the avian.
10
Digestive System Parts and Functions - Avian

• Beak procure food
• Crop feed directly here from esophagus
• -feed stored and soaked with water
• Proventriculus True stomach in Avian
  species, adds and mixes in
• Hydrochloric acid HCl, breaking of bonds
• Pepsin proteins to polypeptides

11
Digestive System Parts and Functions - Avian

• Gizzard Contains grit, food is crushed and
  ground to smaller particles by strong muscular
  contractions.
• Small Intestine Same as swine
• Cecum/Large Intestine Same as swine

12
Ruminants 4 compartment stomach -Designed for
fiber digestion with a high capacity -microorganis
ms in rumen to digest fiber symbiotic
relationship Capacities of different parts?
Figure 64  Digestive system of the ruminant.
13
Digestive System Parts and Functions - Ruminants

• Mouth like swine, no enzymes
• Stomach compartments
• 1. Reticulum (honeycomb)
• - hardware disease?
• 2. Rumen (fermentation vat)

14
Digestive System Parts and Functions - Ruminants

• Functions of the Rumen
• Vat contains slurry of fluid, grain (bottom),
  boluses of forage and microorganisms
• Microorganisms are bacteria and protozoa, type
  changes with type of feed consumed (grain vs
  forages)
• In ruminants, microbes present will break down
  feed and
• Produce energy to be absorbed through the rumen
  as VFAs
• Synthesize more microbes (comprised mainly of
  protein) that are digested as a PRIMARY source of
  protein for the animal
• Synthesize ALL essential amino acids and B
  Vitamins

15
Digestive System Parts and Functions - Ruminants

• Functions of the Rumen - continued
• Major VFAs are Acetate, Propionate and Butyrate
• Process of digestion of food by microbes is
  fermentation
• Rumination is regurgitation of forage boluses
  from rumen and reticulum
• Eructation is the belching of gases (CO2 and
  Methane) produced by the fermentation process
  bloat

16
Digestive System Parts and Functions - Ruminants
Is the rumen functional in newborn ruminants???
Figure 65  Side view (right side) of the rumen.
17
Digestive System Parts and Functions - Ruminants

• Stomach compartments - continued
• 3. Omasum (manyplies)
• - adds water to or absorbs water from rumen
  contents
• 4. Abomasum (true stomach)
• -performs very similar functions as in
  monogastric animals

18
Digestive System Parts and Functions - Ruminants

• Small Intestine Similar to swine
• Cecum/Large Intestine Similar to swine

19

• Pseudo Ruminants Monogastric, single
  compartment stomach
• have a greatly enlarged cecum.
• have a large amount of hind gut
  fermentation.
• digest fiber, can use forages as part of diet

20
Digestive System Parts and Functions - Horses

• Functions of the Cecum
• microbes present break down the plant fiber
• Produce energy to be absorbed through the cecum
  as VFAs
• less efficient than rumen
• Synthesize more microbes, vitamins and amino
  acids, not digested and used as efficiently,
  since cecum is downstream of digestive organs
  (stomach and small intestine) Some are absorbed
• Require higher quality feed and forage than
  ruminants

21
Nutrients

• 6 major classes
• Water
• carbohydrates -
• lipids -
• proteins
• vitamins
• minerals

Energy
22
Figure 51  The essential nutrients. 1Mnemonic
device for remembering essential amino acids 5
MATT HILL VP. 2For poultry, two additional amino
acids are needed glycine and proline. 3Arachidoni
c acid can be synthesized from linoleic acid if
it is available so it is only essential if
linoleic acid is absent or in short
supply. 4Authors vary on whether or not to list
sulfur as a macromineral or micromineral. The
discrepancy arises because only a very small
amount of inorganic S is needed but the
sulfur-containing amino acids (organic S) are
needed in larger quantities.
23
Nutrients

• Water
• Functions
• part of metabolic reactions
• transports nutrients
• temperature regulation
• moisture in feed?
• in grazed forages, silage, hay, corn?

24
Nutrients

• Carbohydrates
• Types
• simple starches sugars
• complex cellulose (plant cell walls fiber)
• Function
• source of energy
• monogastrics from grains or cecum (horses)
• ruminants from volatile fatty acids

25
Nutrients

• Lipids (fats oils)
• most feeds contain 1-5 fat or oil
• composed of 3 fatty acids glycerol
• Functions
• energy source
• 2.25 x more energy than carbohydrates

26
Nutrients

• Proteins
• 25 amino acids are building blocks of animals
• 10 essential amino acids not synthesized by
  body tissues
• Provided by microbial synthesis in ruminants
• Must be in diet of all monogastrics
• 1st limiting LYSINE
• only nutrient containing nitrogen (16)

27
Nutrients
Figure 51  1Mnemonic device for remembering
essential amino acids 5 MATT HILL VP.
28
Nutrients

• Function of Proteins
• supply amino acids for body proteins
• - muscle bone connective tissue hormones
  enzymes antibodies milk components cell repair

29

• small amounts for specific body functions
• 2 classifications
• water soluble C B-complex (see Fig 5-1)
• microbes synthesize in ruminants horses
• fat soluble A, D, E, K
• A E required in diets of all animals
• D produced by effects of sun on skin
• K synthesis by rumen/cecum microbes

30
Nutrients

• Vitamins
• Functions
• enzyme cofactors blood clotting bone health
  health of internal linings of body
• deficiencies lead to specific disorders

Example Disorders blood clotting K scurvy
C
31

• Minerals
• inorganic (contain no carbon) are elements

32
Nutrients

• Mineral Functions
• -part of some amino acids vitamins metabolic
  reactions enzyme function body structure
  transport oxygen
• Deficiency examples

White muscle selenium Grass Tetany magnesium Ric
kets calcium
White hair on black cattle copper Anemia iron Re
tained Placenta selenium and Vitamin E
33
Figure 59  Schematic diagram for partitioning
energy values of feeds. (Source Adapted from
Wagner, 1977. Used with permission.)