Ruminant Compartments
The first compartment of the ruminant digestive system that is referred to as the honeycomb.
Bonus (100 points): what are its main functions (hint: 3) and are any enzymes secreted here?
The Reticulum
Bonus: The main function is particle sorting, regurgitation, traps hardware and there is no enzyme secretion here.
Which species can break down cellulose with their microbial population?
Ruminants
Which hormone functions to inhibit gastric emptying, stimulates insulin release.
Gastric Inhibitory peptide
Where does the bulk of digestion occur?
Bonus: What does this region consist of?
The Hindgut 60-70%
Bonus: Cecum, large intestine, small colon, rectum
The difference between intake and excretion is defined as
Total digestibility
Which compartment is the largest in the ruminant? What is this compartment's function?
Rumen (paunch)
Function: Fermentation vat, Muscular contractions for mixing feed, contain papillae for catching feedstuff
How do ruminants release the methane gas produced from digestion?
Bonus: Which feed type causes more gas: A high concentrate diet or a forage-based diet
Eructation
Bonus: Forage based diet
Which hormone functions to stimulate acid secretion by the stomach and growth of stomach cell lining.
Gastrin
What does the foregut consist of?
Mouth, esophagus, stomach, small intestine
Difference between intake and excretion but collected at end of small intestine is defined as
Ileal digestibility
List the the compartments of the ruminant in the order that feed flows.
1.recticulum, 2. rumen, 3. omasum, 4. Abomasum
rats run on apples
What are the two products of fermentation?
Bonus: what are the functions of the products?
Volatile fatty acid (VFA) and Microbial cell protein (MCP)
VFA: serve as a major energy source in ruminants-
absorbed through the rumen.
MCP: Bacterial synthesis of amino acids and protein
Which hormone functions inhibit acid secretion and stimulate bicarbonate production.
Secretin
What are the 3 volatile fatty acids and their substrates?
Bonus: Which two are Lipogenic? which one is gluconeogenic?
Acetic acid (acetate-energy for processes ex. lactation), Propionic Acid (propionate- contributes to marbling), and Butyric acid (butyrate- energy for contractions)
Bonus: Acetate and butyrate are lipogenic, Propionate is gluconeogenic
identical to ileal digestibility but also takes into account nutrients from digestive enzymes and sloughed intestinal cells
True digestibility
What is the first glandular portion of the GIT that is referred to as the true stomach? What enzymes are secreted here?
The abomasum
HCL, Pepsinogen, and Lysozymes- breaks down bacterial cell walls
True or False: Methane is a gain of energy
False: it is a loss of energy (losing carbon)
Which hormone functions regulate growth hormone release.
Somatostatin
Define coprophagy. Why does this action happen?
Feces eating, happens in animals that depend on cecal fermentation if something in their diet is deficient.
EX. protein
Diffusion is defined as
Movement of molecules from a region of high concentration to low concentration without expenditure of energy
List the 6 ways the rumen maintains favorable conditions for microbes.
1. Constant Temperature 102oF
2. Constant pH (5.5-7.0) - buffered
3. Motility - mixing of digesta
4. End products removed - no accumulation of end products
5. No humoral defense mechanisms
6. Continuous nutrient supply
What are the 4 main microbes in the ruminant's digestive tract? what do they digest?
Cellulolytic (digest cellulose)
Hemicellulolytic (digest hemicellulose)
Amylolytic (digest starch)
Proteolytic (digest proteins)
Which hormone functions to regulate gastric emptying, stimulates pancreatic and gallbladder secretions, and thought to be one of the key hormones regulating feed intake.
Cholecystokinin - CCK
What two species are hindgut fermenters?
Bonus: Between Hindgut fermenters and ruminants, which digestive system is more efficient at digesting fibrous feeds?
Rabbits and horses
Bonus: Ruminants are more efficient at breaking down fibrous feeds as hindgut fermenters need to eat more to get the same amount of nutrients as a ruminant would obtain.
What are 3 factors that absorption depends on?
•Size of molecule
•Chemical properties
•Site of absorption