GI Nutrition- Comparative guts Flashcards
What is the biting method for dogs?
Food is seized by incisor and canine teeth then brought into the mouth by jerking movements of the head and jaw
What is the biting method for ruminants
use tongues to grab food, swallows grass whole
What is the biting method for chickens?
garbs food whole and passes it to the tongue
What is the biting method for rabbits?
bite and tear the food quickly so they are able to run off
What is the biting method for horses?
lips and incisor teeth cut or tear vegetation by jerking movements of the head
Where is the jaw joint in carnivores and omnivores
same plane as molar teeth, so they can only move their jaw up and down
Where is the jaw joint in herbivores and humans?
above the plane of molar teeth so jaw can move up and down and left/right
What are the incisors like in dogs and cats?
short, pointed and prong-like- used for grasping and shredding - Canines are elongated and dagger like
What are the molars like in dogs/cats?
flattened and triangular with jagged edges, function like serrated-edged blades
What is the chewing mechanism like in pigs?
crushing and grinding movements, very rapid rate of mastication
What is the chewing mechanism like in ruminants?
partial chewing, regurgitation and rumination
What are two purposes of chewing?
Break food down so its small enough to swallow and to produce saliva
Why is saliva important in cows?
it contains massive amounts of bicarbonate and phosphate which aids microbial growth and therefore fermentation, binds to plant tannins and recycles urea
Why is saliva important in horses?
buffers the proximal stomach, source of bicarb and reduces risk of choking
Food processing in dogs
they have wider inter-dental spacing, less area for food impaction and stagnation- diets low in fermentable carb and the acids produced by fermentation are buffered by saliva
Which animal does not have salivary amylase to break down starches?
Dogs
What is the appearance and purpose of the reticulum
honeycomb appearance, grey in colour- mechanical grinding and light grey in colour
What is the purpose and appearance of the rumen?
inner surface is covered in papillae, papillae are needed for absorption of bacterial fermentation byproducts
What is the purpose and appearance of the abomasum?
glandular, J-shaped, equivalent to monogastric stomach- acid digestion not a holding chamber
What is the purpose and appearance of the omasum?
heavy, hard organ that contains ‘leaves’, purpose is water absorption and its used to grind up food particles
Function of upper stomach in horses?
Microbial fermentation and saliva buffering (non-glandular) produces VFA’s
Function of lower stomach in horses?
Highly acidic, stops fermentation of food- where protein digestion begins, contains a thick mucus membrane (glandular)
Function of crop in poultry?
out-pocketing of oesophagus, temporary storage pouch- feed and water stored- allows bird to consume food first and hide from predators
Proventriculus
True stomach, Glandular, secretes HCL and enzymes
Ventriculus/ Gizzard
Mechanical stomach, grinds food and acts as the birds teeth
What is the anatomy of the pigs stomach?
low pH to kill bacteria, mucous to protect from acid
What is the anatomy of the dogs stomach?
large holding chamber to contain meal, acidic to break down protein
How does the small intestine digest food?
by enzymes, rapidly (digests high calorie feeds)
where is the muscular ampulla?
at the end of the ileum, in rabbits its a site of possible impaction
What are reabsorbed in rabbits?
VFA’s, amino acids and vitamins digested and reabsorbed from caecotrophs
What occurs in the small intestine in horses?
enzymic breakdown of plant cell contents, starch and absorption of glucose, digestion of amino acids and proteins
What occurs in the small intestine in rabbits?
Digestion of most nutrients, absorbing microbial protein and minerals from caecotrophs
How is the caecum different in rabbits?
Much smaller, fibre is only partially digested- they compensate via caecotrophy
What are the anatomical differences in rabbits?
there is a specialised lining ‘haustra’ that acts as a sieve and separates indigestible fibre from soluble fibre
What happens to the different particles in rabbits?
large undigestible particles are unfermentable, fibre goes straight to colon and is excreted
What are the teeth numbers for a dog
3,1,4, 2 on top and 3,1,4,3 on bottom
What are the teeth numbers for a pig?
3,1,4,3
When is less saliva produced in cows?
When they are eating good quality pellets/cereals that do not require as much breaking down
Which stomach in horses is glandular?
The lower stomach
Why should glucose be fermented in the small intestine rather than the large?
Fermentation of glucose causes a build up of lactic acid which can kill off the good bacteria
How are dog stomachs adapted for high protein meals?
Very acidic, this allows proteins to become denatured and break down
Why can dogs digest carbohydrates?
They do secrete amylase in their pancreas, they have adapted to digest carbohydrates
