Before Test 1, Part 2 Flashcards
What are the two ways that we classify animals in terms of feeding?
Digestive anatomy/ physiology (Monogastric? Ruminate?)
Normal food preference (Carnivore, omnivore…?)
Describe the three main food preferences
Carnivore: eats meat
Omnivore: Eats meat and plants
Herbivore: Eats plants. (Often the leafy part)
What is one stipulation that is important in food preference?
It is what the animal would eat when given a choice! Ex: A dog forced into a vegan diet by its owner.
What kind of system do we use when classifying animals into eating patterns?
A dual system!
Ex: dogs are monogastric carnivores.
Monogastrics can be ____, ____, and ______
Ruminants can be _____ and maybe _____?
Carnivores, omnivores, herbivores.
Herbivores, omnivores?
In talking about plants, what is a cereal?
Generally the seed portion of a plant
What are some characteristics of cereals
High in energy (oil content in grain,) low fiber and no cellulose!
What are some examples of feed cereals?
Oat, corn, rice, wheat, barley, ect.
What is a roughage or forage?
Generally the leaves or stems of plants.
What are some characteristics of roughages?
Low in energy, high in fiber, contain a lot of cellulose and or lignin.
What are some examples of common roughages?
Grass, hay, silages, ect…
What is the simple, working definition of digestion?
The process by which feed particles are reduced to molecules so that they can enter the body.
Absorbtion is the same as digestion.
False! Digestion ONLY includes breaking down food.
What are the three types of digestion?
Mechanical action: Chewing and gut motility
Chemical action: Acidic breakdown of food.
Enzymatic action: Biological cleavage of food.
What is the definition of absorption?
The process by which molecules are transported from the digestive tract, through intestinal cells, and enter the vascular or lymph systems.
Can you have digestion without absorption?
What about absorption without digestion?
Yes to both!
Ex: Digestion without absorption: diarrhea
Ex: Absorption without digestion: energy drinks.
What are the two types of absorption?
Passive diffusion
Active transport.
Define passive diffusion in absorption.
Molecules enter body without using energy.
Define active transport in absorption.
Molecules are transported into the body against the concentration gradient. This requires energy!
In monogastric, herbivores carnivores, and omnivores, all have different systems and organs.
False! The organs are the same regardless
What is the order of the organs in a monogastric digestive system?
Mouth, esophagus, stomach, pyloric sphincter, small intestines, cecum, large intestines, rectum.
The cecum is a _______ _____. What does this mean?
Blind pouch. Food goes in and then back out through the same entrance.
Where is the cecum located?
In between the small intestine and the large intestine.
Describe the function of the mouth in digestion.
Mechanical digestion. Reduces particle size by chewing.
In some species (humans included) enzymatic digestion! Amylase breaks down starches into sugars.
In the very beginning of the digestive system, how do avians differ from other monogastics?
Very little mechanical digestion in the mouth.
Explain the role of the esophagus in digestion.
Transports food from mouth to stomach via peristalsis.
No digestion or absorption happens here!
what is chyme?
The mix of partially digested food with stomach secretions (yum)
Explain the role of the stomach in digestion.
Chemical, Enzymatic, and Mechanical!
Chemical: HCI secretions break down proteins.
Mechanical: Churning, anatomical folds increase surface area of chyme.
Enzymatic: Gastrin and pepsin. Break down proteins into polypeptides.
Does absorption happen in the stomach?
NO!
Why do you want most of your chemical and mechanical digestion to be done before enzymatic digestion starts?
So that the enzymes have a bigger surface area to work!!
Enzymes work on the surface of chyme. It needs to be small pieces for enzymes to be effective.
What is the function of the small intestine in digestion and absorption?
Major site of enzymatic digestion in monogastric animals that are NOT herbivores.
Also includes chemical digestion via bile.
Most efficient site of absorption of nutrients in ALL animals.
Why is the small intestine perfect for enzymatic digestion and absorption?
It is long and skinny! Increases surface area for enzymes to work.
It is highly vascular to aid in absorption.
Why is the small intestine red and the large intestine is not?
The small intestine is highly vascular to aid in absorption! The large intestine does less absorption.
What does the liver do in the digestive process?
Produces bile. This breaks down fat.
What organ stores bile?
The gallbladder.
Describe the cecum
A blind pouch in the junction of the small and large intestine.
In monogastrics, what is the function of the cecum?
To break down complex sugars and cellulose. Using microbes and protozoa
This allows monogastric to consume leafy plants.
Animals don’t produce ____ on their own. _____ that live in the cecum produce it instead. This is an example of a perfect _________ relationship.
Cellulase. Microbes. Symbiotic.
What breaks down cellulose?
Cellulase.
Why can plant material not be digested and absorbed without passing through the cecum or rumen?
Cellulose creates a plant cell wall and must be broken down with cellulase.
What does the large intestine do in digestion and absorption?
water reabsorption, concentrates undigested feed into waste.
Very little digestion and nutrient absorption happens here.
What is the role of the rectum and anal sphincter?
Thick muscular tube that gets rid of solid undigested material
What is the main reasons ruminates have four stomach compartments?
It allows the animal to digest forages.
What are the four compartments of a ruminate stomach?
Reticulum, rumen, omasum, and abomasum.
What is the easiest way to remember the four stomach compartments of a ruminant stomach?
It is in reverse alphabetical order!
If you have a 3D model of a ruminate stomach, and you cant figure out where each compartment is, what is the easiest way to do it?
Point the esophagus at your bellybutton. Everything to the right is the rumen. On the left, the three compartments now move in order. (Reticulum, omasum, abomasum.)
Why is the esophagus generally in the middle of the reticulum and the rumen?
Most ruminates chew cud. This involves feed going into the reticulum, rumen, and then coming back up the esophagus.
Which compartment of the ruminate stomach is often called the “true stomach?”
The abomasum (The last one)
The rest of the digestive tract (past the stomach) is the same in monogastics and ruminates.
True! although organ size will differ.
Describe the functions of the Reticulum
Mainly enzymatic digestion!
Assists with fermentation.
Contracts to push food back up for chewing cud.
What is one very unique characteristic or the reticulum?
Its inner lining has a honeycomb pattern.
Describe “double digestion” and how it affects ruminants.
Microbial action digests nutrients and then the animal digests the remains and absorbs them.
Describe the Rumen
Enzymatic digestion
The rumen is the largest compartment in the stomach. It is a very large sack.
The rumen contains lots of microbes that break down cellulose in forages. This “unlocks” the nutrients and will allow the rest of the digestive tract to do its job.
The rumen doesn’t secrete anything!
What is the omasum’s role in digestion? How does it achieve this role?
ONLY mechanical digestion.
It has many folds (plies) that are visible in the lining.
What is the abomasum’s function in the digestive system?
Mechanical, chemical enzymatic.
Same as the stomach in non-ruminants!
Why is the cecum LESS important in ruminant animals? What is its main function?
The rumen contains cellulase, which breaks down cellulose in forages.
By the time feed reaches the cecum in ruminants, most of the cellulose should be unlocked.
The cecum is more of just clean up!
Why do ruminates function the way they do?
Most are prey animals! They eat a lot of food and grasses, store it in the rumen, and they chew when they had time and safety.
List all parts in order of the ruminate digestive system.
Mouth, Esophagus, Reticulum, rumen, (Mouth again sometimes,) Omasum, abomasum, pyloric sphincter, small intestines, cecum, large intestines, Rectum.
Most birds are ______, but they can be _________ or ________
Omnivores, Herbivores, Carnivores.
Why is the liver significantly smaller and less important in ruminate animals?
Its main function is to break down fat. Ruminates are generally herbivores and do not eat much fat.
How can you tell a ruminate from a monogastric?
A monogastric does not have four stomach compartments.
How can you tell a monogastric herbivore from a monogastric carnivore?
In the herbivore, the cecum will be dramatically bigger while the liver will be much smaller.
In a carnivore, the liver will be much larger while the cecum will be much smaller.
What is the biggest reason that the digestive system of birds is so different?
So that they are light enough to fly.
How is the mouth on birds different and how do they compensate for this?
They have no teeth. Instead, they reduce particle size by pecking or scratching with their feet.
What is the function of the crop in a birds digestive system?
-Feed goes from esophagus to crop.
-A modification of the esophagus where feed can be stored. Generally, this is the sole function.
-very very limited enzymatic digestion by microbes can take place.
In birds, describe the function of the proventriculus.
-Enzymatic digestion: HCI and gastric enzymes digest feed.
-Little to no mechanical digestion.
What is considerd the stomach in birds?
The proventriculus.
What is the big main difference between our stomachs and a bird’s proventriculus?
There is very little mechanical digestion in a birds proventriculus.
There is a lot of mechanical digestion in the monogastric stomach.
Describe the role of the gizzard in birds.
Mechanical digestion: Reduces particle size of feed.
The gizzard is similar to a mortar and pestle. It is very muscular and has a lot of cartilage that grinds down feed.
What is another name for the gizzard?
Ventriculus.
What is the heaviest part of a bird’s digestive tract? How does it factor into its location?
The gizzard/ventriculus.
This part is located close to the middle to keep the animal balanced and allow them to fly.
Different than other monogastics or ruminates, birds have _____ ____.
Two cecas (Cecums)
In a bird, where are the ceca located?
On either side of the junction between the small intestine and the large intestine.
Why might birds have two cecas?
To keep them balanced during flight.
What is the cloaca’s role in birds?
It is the common hole in the bird used for everything. Waste, urine, and reproduction.
List the organs of a birds digestive system in order.
Mouth, esophagus, crop, proventriculus, pyloric sphincter, gizzard (Ventriculus), small intestine, ceca (x2), large intestines, colaca.
Birds have a different order to their digestive functions. They start with ______ and then move to ______ digestion.
Enzymatic digestion, mechanical digestion.
In the small and large intestines and ceca of birds, digestion and absorption is similar to other nonherbivore monogastric.
True!
What is the biggest difference in the system of monogastric herbivores versus omnivores and carnivores?
The cecum is much much larger in monogastric herbivores.
What are some examples of monogastric herbivores?
Horses, rabbits….
You should be able to tell an animals diet from three anatomical things:
Cecum size, liver size, teeth shape.
In a monogastric herbivore, what digestive functions does the stomach preform? Why?
ONLY mechanical and chemical.
The food particles are still locked down by the cellulose. No enzymatic digestion can occur until the feed travels through the cecum.
Because monogastric herbivores have a larger system, the digestive system is still able to process roughages at a similar efficiency as ruminates.
False! The monogastric herbivore’s digestive system is very inefficient. Cellulase does not get introduced early enough for the body to extract all of the nutrients.
Different animals have developed different ways of coping with this.
How do horses compensate for their inefficient digestion?
They simply increase their intake of food. Horses eat almost all day.
How do rabbits compensate for their inefficient digestion? Why does it work?
When rabbits produce waste, they are either soft or hard pellets. The rabbits eat the soft pellets and they pass through the digestive system again.
This works because now, after the first pass through the cecum, the cellulose is gone. The small intestine can absorb the nutrients much easier the second time.
What are the three practical aspects of nutrition?
Nutrient requirements, diet content, and nutrient intake.
____% of the variable cost in Rasing livestock is _____
70%, nutrition.
Why do nutritionists get paid so much?
Nutrition is directly tied to the health and size of an animal.
Nutritionists can help grow animals to their best, so that you can get the most money out of the animal.
____ increase in efficiency in animal feed conversion to weight is worth about $______
1/10, 5 million dollars.
What are some factors that can change how much and what kind of feed that an animal needs?
Size, maturity, pregnant, lactating, in heat.
Why are we constantly having to reevaluate our food requirements for certain animals?
We are constantly changing and improving the genetics of livestock. This changes how they process food.
What is the first step of finding out how much to feed an animal?
Look at a nutrient requirement table. Then figure out how this animal expresses information.
To figure out nutrient requirements, Body weight must be converted to metabolic body weight in what animal?
Dogs!
Why do dogs measure in metabolic body weight?
Likely because there is so much weight variation between the species. Think great Dane versus Jack Russel.
All diets and feeds have a certain _____/_____ of nutrients. This information can be found where?
Amount/concentration.
On the feed label or through a feed analysis report.
Assume you are asked: How much does a 10 kg dog in early growth need to eat of this diet each day to meet his/her protein (metabolizable) needs?
What is the first step to solve this?
Find the early growth row and see what the ratio is for protein grams to body weight.
Assume you are asked: How much does a 10 kg dog in early growth need to eat of this diet each day to meet his/her protein (metabolizable) needs?
Assume that the requirement is
6 grams/kg body weight^0.67/day
What is the next step?
Use a calculator and plug in the 10 kilograms. This gives metabolic body weight. Your answer should be 6 grams/4.6 kg / day
Assume you are asked: How much does a 10 kg dog in early growth need to eat of this diet each day to meet his/her protein (metabolizable) needs?
Assume that you have gotten the equation
6 grams/4.6 kg/ day
What now?
Multiply them! You should get 28.2 grams.
Metabolic body weight is only used for:
Dogs.
Assume you have calculated that a dog needs 28.2 grams of protein a day. You need to figure out how much metabolizable protein is in each gram of dog food.
What is your first step?
Look at a feed analysis report! It will tell you the correct percentage.
Assume you have calculated that a dog needs 28.2 grams of protein a day. You need to figure out how much metabolizable protein is in each gram of dog food.
Also assume that the diet content is 25% metabolizable protein.
What is the next step.
Convert the 25% into a decimal. (0.25)
This means for every 1 gram of feed, 0.25 of that is metabolizable protein.
Assume you have calculated that a dog needs 28.2 grams of protein a day. You need to figure out how much metabolizable protein is in each gram of dog food.
Also assume that the diet content is 25% metabolizable protein.
What is the last step?
DIVIDE the dog’s protein requirement by the decimal version of the amount in each gram of dog food.
28.2/0.25 = 112.8
This is your answer.
How many grams are in a pound?
454
