“WE ARE WASHINGTON: PEOPLE OF THE FAIR”9.
After squeezing the bag for two minutes, have participants remove the paper towel and observe the changes
to the contents of the bag. They should not open their bag.
10. While observing the changes to the bread, ask participants the following questions:
• What caused the changes to the bread?
• Would the change have been different if the liquid added was water? Why or why not?
Answer: Yes. The acids in orange juice or cola accelerate the breakdown process.
• How does this lab relate to animal digestion?
Answer: When the stomach of an animal receives fluid, the consumed contents in the stomach
are churned like the squeezing action of the stomach.
11. Go around the room with a trash bag and have participants place their entire bag in the trash.
Expansion
1.
Review the digestion process in monogastric animals and humans. Place participants in a straight line and have each
participant name a step. For example: In monogastric animals, food is placed in the mouth, chewed by the teeth and
swallowed. It then moves down the esophagus to the stomach. In the stomach the food is churned and digestive acids
begin to break down the food. From the stomach, food travels to the small intestine where the majority of digestion will
take place. After the small intestine, food travels to the cecum, large intestine and rectum before exiting through the anus.
2.
Once participants have reviewed the general digestion process, explain that ruminant animals are similar to monogastric
animals in that they have four compartments to their stomach and are cud-chewing.
3.
Ask participants, “What does it mean when someone says an animal is chewing its cud?”
4. Select participants to share their responses. Make sure to highlight that the cud is food that is regurgitated, re-chewed
and re-swallowed. The purpose of this is to help regulate rumen health and pH while further breaking down fibrous
particles of feed.
5.
To further expand, explain that the ruminant digestive system consists of four compartments. In order of food
passage, they are the rumen, reticulum, omasum and abomasum.
6.
As a review, arrange participants into four equal size groups where each group is assigned a compartment of the stomach.
7.
Give each group 30 seconds to come up with one or two words that describes their stomach compartment.
8.
Then, when pointed to, have each group state their stomach compartment as well as the word or words describing it.
For example:
a.
Rumen = fermentation
b. Reticulum = honeycomb
c.
Omasum = many folds
d. Abomasum = mixes
9.
As a closing, challenge participants to think about how livestock digest the food they eat. Are some things quicker
or harder for the animal to digest?
Source
Additional resource
5
