Comparative Guts Flashcards
Teresa - Nutrition
What do carnivores primarily consume?
primarily animal tissue
what do herbivores primarily consume?
plant material
what do omnivores primarily consume?
plant and animal tissue
What are the anatomical adaptations which allow for prehension and mastication?
mouth and teeth
How does the stomach aid in digestion?
it is the holding chamber and used during pre-digestion
what occurs in the small intestine?
digestion and absorption
what occurs in the large intestine?
digestion and absorption
what are the components of the small intestine?
duodenum, jejunum and ileum
what are the components of the large intestine?
the caecum, colon and rectum
Describe the biting method of a dog - prehension:
food is seized by the incisor and canine teeth; brought into mouth by jerking movements of the head and jaw
Describe the biting method of a pig- prehension:
rooting, feral pigs - 75% of their active time in foraging related activities e.g. rotting, grazing and exploring with their snout
Describe the biting method of a chicken- prehension:
picks up their food in toothless beak, passes to the base of tongue preparatory to swallowing
what is the selective food behaviour of a dog?
large, infrequent meals - rapid ingestion
what is the selective food behaviour of a pig?
9.2-11.7 meals a day
7.4-5.3 mins per meal
Total time spent eating/day is 60.4-55.7 min
Total intake 2.7-2.8 kg/day
what is the selective food behaviour of a chicken?
influenced by colour
what are the food preferences of a dog?
meat
what are the food preferences of a pig?
varied diet; anything that has nutritional value e.g. roots, shoots, fruits, worms, amphibians and rodents
what are the food preferences of a chicken?
grains, insects, some grass, grit
Describe the biting method of a ruminant- prehension:
long, muscular tongue pulls grass/hay into mouth, cutting it between lower incisors & upper gum by upward movement of head & neck (sheep use lips)
Describe the biting method of a horse- prehension:
lips & incisor teeth cutting or tearing the vegetation by jerking movements of the head or neck
Describe the biting method of a rabbit- prehension:
bite/tear
Describe the selective food behaviour of a ruminant:
rapid ingestion of high quality grass, very limited initial chewing, retreat to safety of herd to ruminate
Describe the selective food behaviour of a horse:
able to choose low quality grasses that are short. trickle graze, bite and then spend time chewing before swallowing and then move to the next area. Spend 16-18 hrs in 24 hours grazing
Describe the selective food behaviour of a rabbit:
rapid ingestion of high-quality pasture at dawn and dusk
what are the food preferences of ruminants?
pasture
what are the food preferences of horses?
pasture
what are the food preferences of rabbits?
pasture
Where is the jaw joint located in relation to the teeth in a carnivore?
same plane as molar teeth
Where is the jaw joint located in relation to the teeth in a herbivore?
above plane of molars
Where is the jaw joint located in relation to the teeth in a omnivore?
same plane as molar teeth
Where is the jaw joint located in relation to the teeth in a human?
above the plane of molars
describe the jaw motion in a carnivore:
carnivore shearing, minimal side to side motion
describe the jaw motion in a herbivore:
no shear, good side-to-side, front-to-back
describe the jaw motion in an omnivore:
shearing, minimal side-to-side
describe the jaw motion in a human:
no shear, good side-to-side, front-to-back
type of jaw joint for a carnivore?
it is a hinge-type joint
describe the movement of the jaw for a hinge-type jaw joint of a carnivore:
when a carnivore closes its jaw, the cheek teeth act in a back-to-front fashion = smooth cutting motion
describe the movement of the lower jaw of a carnivore:
it cannot forward, very limited side-to-side motion
describe the incisors of a carnivore:
the incisors are short, pointed & prong-like, used for grasping and shredding
describe the canines of carnivors:
they are elongated & dagger-like for stabbing, tearing and killing prey
describe the molars (carnassials) of carnivores:
they are flattened and triangular with jagged edges; function like serrated-edged blades
describe the jaw joint of herbivores:
it is less stable than hinge-type joint of the carnivore
it is mobile and allows the complex jaw motions
describe the molars of herbivores:
upper and lower premolars and molars meet along length of the jaw and provide a grinding platform
describe the mandible of herbivores:
wide angle of the mandible provides broad area of attachment for the well-developed masseter & pterygoid muscles
what do the masseter and pterygoid muscles hold?
they hold the mandible in a sling-like arrangement to swing the jaw from side-to-side
describe the surface area of the jaw of herbivores:
wide flattened surface area
ruminants have greater surface area
GIT of carnivore and which one does the majority of fermentation take place in?
STOMACH, small intestine and large intestine
GIT of ruminants and which one does the majority of fermentation take place in?
FORE-STOMACH, stomach (abomasum), small intestine, large intestine
GIT of single stomached herbivores and which one does the majority of fermentation take place in?
stomach, small intestine and LARGE INTESTINE
GIT of birds and which one does the majority of fermentation take place in?
crop, pro-vestriculus, gizzard, small intestine, large intestine
minimum sward height grazed by sheep?
3cm
minimum sward height grazed by cattle?
> 6cm
minimum sward height grazed by horses and ponies?
2cm
minimum sward height grazed by rabbits?
1cm
minimum sward height grazed by goats?
> 6cm
minimum sward height grazed by red deer?
1cm
minimum sward height grazed by mountain horses?
3cm
good grinding movement teeth structure?
wide flattened surface area
ruminants greater surface area
What is the relevance of chewing?
1.break down food so small enough to swallow
2. saliva production - some animals produce saliva in anticipation of food
others only when physically chewing (horse)
more chew = more saliva
1ml of saliva for every chew
bicarbonate is found in?
saliva
importance of saliva in cow? (26)
importance of saliva in horse? (26)
which requires most chewing?
straw
27, 28
tooth shape of dog?
conical tooth shape
spacing in a dog’s mouth?
wide inter-dental spacing
reduced stuff stuck in teeth as they don’t have saliva to help get it out
29
what maintains dental health in dogs?
low carb and dental anatomy maintains dental health
what shows a healthy ruminant mouth?
adequate lateral grinding and routine dental care will help maintain gut health and mouth to bottom
31,
simple stomached?
monogastric
anatomy function of the stomach of cows, sheep, goats (ruminants)
have a large complex four chambered stomach - four stomachs
fermentation of plant material, buffered by saliva
33,34,35,36
unfed pH of dog’s stomach?
pH = 1.8
one of the most acidic stomach?
dog
post prandial pH of dog?
pH = 2.1
38, 39
4 stomachs of ruminants?
rumen, reticulum, omasum, abomasum
reticulum?
‘honeycomb’ appearance, a light grey in colour
mechanical grinding and stores non food objects
41
saliva buffering pH of horses stomach?
pH 6.2-6.8
acidity of horses stomach?
very - pH 2
pH for saliva buffering?
pH 5
44
1g starch per bodyweight per meal
doesn’t overwhelm small intestine (horses) and maintains healthy bodyweight
how do we maintain a healthy stomach?
match meal size to stomach size
no more than 1g of starch per kg per meal
small nets of hay –> reduced dry matter accumulation in stomach
46, 47, 48
Describe the formula of the teeth for dogs:
3/3, 1/1, 4/4, 2/3
Describe the formula of the teeth for pigs:
3/3, 1/1, 4/4, 3/3
Describe the formula of the teeth for ruminants:
0/4, 0/0, 3/3, 3/3
Describe the formula of the teeth for horses:
3/3, 1/1, 3/3,4 , 3/3
Describe the formula of the teeth for rabbits:
2/1, 0/0, 3/2, 3/3
What is the chewing mechanism for dogs?
vertical movement only, tear and rip food, gnaw till small enough to swallow
What is the chewing mechanism for pigs?
crushing and grinding movements, consecutive bilateral grinding, a very rapid rate of mastication
What is the chewing mechanism for chickens?
pecking food whole
What is the chewing mechanism for ruminants?
Partial chewing, regurgitate and ruminate
Mechanically disrupts plant cell walls
What is the chewing mechanism for horses?
Chew intensively cellulose in grasses and highly abrasive to teeth
What is the chewing mechanism for rabbits?
shearing, rapid irregular surface, help to crush hard fibrous food
Describe the importance of saliva in cows - focusing on the amount of bicarbonate + phosphate:
saliva contains massive amounts on bicarbonate and phosphate which aids microbial growth and therefore fermentation in rumen
pH = 8.2
Describe the importance of saliva in cows - focusing on its ability to recycle:
it recycles nitrogen and minerals used by bacteria in rumen
it also recycles urea and binds plant tannins
As saliva is high in bicarbonate - what does this enable saliva to do?
it enables saliva to buffer 1/3rd acids produced by bacteria
Importance of saliva for both horses and cows?
it maintains pH above 5, ensures fermentation and minimises risk of acidosis
importance of saliva to horses?
acts as a buffer in upper proximal stomach to keep pH at 6 (6.2-6.8)
source of bicarb
minimises risk of choke
what enzyme does the dog lack in its saliva?
it lacks the starch digesting enzyme a-amylase in its saliva
this lack is reflected in the eating behaviour of dogs which tend to eat all foods quickly apart from the toughest foods
what food type generates the most amount of saliva for cows and horses?
hay - it is the toughest so requires more chewing therefore more saliva is produced
what type of food generates the least amount of saliva for horses and cows?
pellets concentrate feed
if roughage (forage) quality is poor, what does this mean for saliva production?
they have to chew more in order to get fibre small enough physically to swallow
what does eating very good quality grass or cereal mean for saliva production?
these do not require so much chewing so less saliva is produced
how much saliva is produced from a dogs parotid gland?
mean 0.55ml/min
how much saliva is produced from a dog’s submaxillary gland?
mean 1.31 ml/min
for evaporative cooling
for oral health, what should a dogs diet be low in?
should be low in fermentable carbs
what should the pH be in order to maintain a good oral health for a dog?
higher salivary pH (mean pH 7.5 equivalent of 6.5 in humans)
acids produced by bacterial fermentation of carbs buffered by saliva
why do dogs have to be ‘careful’ when consuming starch - concerning their dental health?
no salivary amylase to break down starches which are retained in and around the teeth
how does the conical tooth shape of a dog help with its oral health?
wider inter dental spacing - less food to get stuck
less area for food impaction and stagnation
with fresh grass, how many chews per second and how many chews per hour does a horse carry out?
1 chew per second
3600 chews per hour
with fresh grass, how many chews per second and how many chews per hour can a ruminant carry out?
0.2 chews per second
734 chews per hour
for fresh grass what is the intake for ruminants and for a horse?
ruminants –> 238g/min
horse –> 66g/min
What is the saliva production when a horse is eating fresh grass?
0.71l/kg
What is the saliva production when ruminants are eating fresh grass?
0.94l/kg
what is the mean total saliva in litre per day for horses when eating fresh grass?
44 litres
what is the mean total saliva in litre per day for ruminants when eating fresh grass?
80l for sheep
150l for cows
saliva provides 70% water enteirng rumen
what is the mean total saliva in litre per day for dogs?
0.5 l
what is the fermentation of plant material in ruminants buffered by?
saliva
what type of fermenters are horses and rabbits?
hind gut fermenters
describe the stomach of the horses and rabbits?
simple stomach & adapted caecum/colon (hindgut)
the stomach has two distinct reigons
describe the stomach anatomy of dogs and pigs:
simple one chambered stomach
acidic stomach
what is the capacity and the relative capacity (of GIT) of the stomach (in litres) for carnivores?
4.3 litres
62.3% rel cap
what is the capacity and the relative capacity (of GIT) of the stomach (in litres) for ruminants?
252.5 litres
70.8% rel cap
what is the capacity and the relative capacity (of GIT) of the stomach (in litres) for horses?
18l
8.5% rel cap
what is the capacity and the relative capacity (of the GIT) of the stomach (in litres) for chickens?
less than a litre
why are larger and longer guts needed?
for adequate retention time for breakdown and absorption of low quality food
you need an increased digestive compartment size - a special enlarged compartment(s) to maintain a microbiota
what is important for fermentative processes?
these processes carried out by symbiotic microorganisms are important for cellulose degradation
what is the complete gastric emptying times of intact kibble fed at 8g/kgBW for a dog? (stomach retention time)
takes 7-9 hours
what is the complete gastric emptying times of ground kibble fed at 8g/kgBW for a dog? (stomach retention time)
5-10 hours
at what size does meat leave the stomach in dogs?
at particles smaller than 2mm in diam
how long does the food stay in the stomach for? (dogs)
- Dried food w/ 10% moisture
8-10 hours
the food = unchanged in the stomach for 480-600 mins after eating
stomach is completely empty after 900 mins
how long does the food stay in the stomach for? (dogs)
- Canned food with 70% moisture
food started to enter the duodenum after 270 mins
stomach appeared empty 420-480 after eating
how long does the food stay in the stomach for? (dogs)
- Fresh food –> fish with 75% moisture
the food in the duodenum 30 min after eating
empty by 240-360 min
describe the form of the rumen (of a ruminant) and how it is adapted for function?
the inner surface is like a shag carpet. These are the papillae that are needed for absorption of bacteria fermentation byproducts (food)
describe the form of the abomasum (of a ruminant) and how it is adapted for function?
it is glandular - equivalent to monogastric (simple) stomach; j haped
acid digestion, not a holding chamber
describe the form of the omasum (of a ruminant) and how it is adapted for function?
it is a heavy, hard organ that contains many ‘leaves’ much like a book
water absorption is used to help grind up food particles
regions of the equine stomach?
upper, lower, non-glandular stomach and glandular stomach
what is the crop of a bird?
it is out pocketing of oesophagus
temporary storage pouch
feed and water stored
allows bird to consume food fast and hide from predators
proventriculus?
it is the true stomah of a bird
it is glandular and it secretes HCI and enzymes
what is the ventriculus/gizzrd?
it is the mechanical stomach of the bird
it grinds food/acts as bird’s teeth
grinds, mixed and mashes
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