Digestion and Absorption part 1
Digestive system of livestock is diverse in anatomy
Overall function: extract and absorb
Reduction of particle size: physical and chemical action
Microbial population are present in all animals
Peristalsis: series of involuntary wave-like muscle contractions which move food along the
digestive tract
Contraction of smooth muscles behind bolus forces the food forward
Waves of muscle contractions move bolus toward the stomach
Enzymes of the pancreas → trypsin and chymotrypsin
These enzymes are important to digestion
These are enzymes that will help to digest proteins:
Amylase for the digestion of carbohydrates and lipase to break down fats.
Horses, cows, and rabbits can survive on a high fiber diet
Types of herbivores
Zebra (ex. Horses, etc.) = hindgut fermenters
- Fermentation occurs in the cecum
Ruminants (ex. Deer, cows, etc.) = foregut fermenters
- Fermentation occurs in the rumen, in the colon
Digestive system in Chickens
➔ They don't have teeth
➔ They don’t chew
➔ They don't break down food that much
➔ Have a gizzard which is an organ that reduces the particles size of the food/breaks down
the food
➔ Caeca → all birds have an organ called caeca
➔ Chickens have two caeca, most animals like humans have one caeca
Digestion
● Degradation of feed materials into absorbable compounds
● Absorbable products: monosaccharides, amino acids, peptides, fatty acids,
monoglycerides, glycerol, vitamins, and salts
● Animals benefit from absorbable products
Note: monosaccharides are types of sugars
, Amino acids are the building blocks of protein
Fatty acids are building blocks of lipids
Absorption
● What is absorption?
○ Consume and store protein and energy
● Absorption and animal’s nutrient requirements
● How can nutrients be absorbed?
○ Active transport, facilitated diffusion, and simple diffusion
● Efficiency of nutrient absorption: passage rate
● Feed processing improves absorption
Processing could be for example grain processing, this can improve the digestibility of the food
Such as grounding corn
This can increase starch indigestibility and improve absorption of the food
Transport across cell membrane
Solutes cross cell membranes by passive or active transport
➔ Simple diffusion: If unchanged solutes are small enough they can move down their
concentration gradients directly across the membrane (the lipid bilayer) itself by simple
diffusion
◆ Examples of such solutes are ethanol, carbon dioxide, and oxygen
➔ Most solutes can cross the membrane only if there is a membrane transport protein (a
carrier protein or a channel protein) to transfer them
➔ Passive transport in the same direction as a concentration gradient occurs
spontaneously, whereas transport against a concentration gradient (active transport)
requires an input of energy.
➔ Only carrier proteins can carry out active transport, but both carrier proteins and channel
proteins can carry out passive transport.
The stomach produces feed proteins and peptides
Small intestines produce amino acids
Amino acids are absorbable compounds
Hay sources are high in cellulose and hemicellulose
Corn is high in starch and sugar
Dietary Proteins
RDP = ruminant degradable protein → amino acids, peptides, ammonia (NH3)
RUP = ruminant undergradedable protein → amino acids
Digestive system of livestock is diverse in anatomy
Overall function: extract and absorb
Reduction of particle size: physical and chemical action
Microbial population are present in all animals
Peristalsis: series of involuntary wave-like muscle contractions which move food along the
digestive tract
Contraction of smooth muscles behind bolus forces the food forward
Waves of muscle contractions move bolus toward the stomach
Enzymes of the pancreas → trypsin and chymotrypsin
These enzymes are important to digestion
These are enzymes that will help to digest proteins:
Amylase for the digestion of carbohydrates and lipase to break down fats.
Horses, cows, and rabbits can survive on a high fiber diet
Types of herbivores
Zebra (ex. Horses, etc.) = hindgut fermenters
- Fermentation occurs in the cecum
Ruminants (ex. Deer, cows, etc.) = foregut fermenters
- Fermentation occurs in the rumen, in the colon
Digestive system in Chickens
➔ They don't have teeth
➔ They don’t chew
➔ They don't break down food that much
➔ Have a gizzard which is an organ that reduces the particles size of the food/breaks down
the food
➔ Caeca → all birds have an organ called caeca
➔ Chickens have two caeca, most animals like humans have one caeca
Digestion
● Degradation of feed materials into absorbable compounds
● Absorbable products: monosaccharides, amino acids, peptides, fatty acids,
monoglycerides, glycerol, vitamins, and salts
● Animals benefit from absorbable products
Note: monosaccharides are types of sugars
, Amino acids are the building blocks of protein
Fatty acids are building blocks of lipids
Absorption
● What is absorption?
○ Consume and store protein and energy
● Absorption and animal’s nutrient requirements
● How can nutrients be absorbed?
○ Active transport, facilitated diffusion, and simple diffusion
● Efficiency of nutrient absorption: passage rate
● Feed processing improves absorption
Processing could be for example grain processing, this can improve the digestibility of the food
Such as grounding corn
This can increase starch indigestibility and improve absorption of the food
Transport across cell membrane
Solutes cross cell membranes by passive or active transport
➔ Simple diffusion: If unchanged solutes are small enough they can move down their
concentration gradients directly across the membrane (the lipid bilayer) itself by simple
diffusion
◆ Examples of such solutes are ethanol, carbon dioxide, and oxygen
➔ Most solutes can cross the membrane only if there is a membrane transport protein (a
carrier protein or a channel protein) to transfer them
➔ Passive transport in the same direction as a concentration gradient occurs
spontaneously, whereas transport against a concentration gradient (active transport)
requires an input of energy.
➔ Only carrier proteins can carry out active transport, but both carrier proteins and channel
proteins can carry out passive transport.
The stomach produces feed proteins and peptides
Small intestines produce amino acids
Amino acids are absorbable compounds
Hay sources are high in cellulose and hemicellulose
Corn is high in starch and sugar
Dietary Proteins
RDP = ruminant degradable protein → amino acids, peptides, ammonia (NH3)
RUP = ruminant undergradedable protein → amino acids
