Students will investigate the different digestive systems of livestock and learn how animals have unique nutritional needs based on these structures. Students will also discover the responsibilities of an animal nutritionist.
Interest Approach — Engagement:
Sticky notes, 2 per student
Animal Appetites handout
Got Guts? Teacher Review
Got Guts? Pig Descriptions
Got Guts? Cow Descriptions
Foam board, 1 per group
Pig or Cow Digestive Tract handout, 1 per group
Modeling materials (balloons, tubing, hoses, straws, string, rope, empty soft drink bottles, chenille stems, milk jugs, and food containers) for each group
Got Guts? Pig Labels or Cow Labels, 1 per group
Tape or glue
Essential Files (maps, charts, pictures, or documents)
diet: the types of food that an animal habitually eats
browse: to feed on leaves, twigs, or other high-growing vegetation
digestive system: the system which physically and chemically breaks down food to provide the body with absorbable nutrients
monogastric: a simple single-chambered stomach
ruminant: an animal with a multi-chambered stomach
graze: to feed on grass
cud: partially digested food from a ruminant animal which is regurgitated to the mouth for further chewing
Did you know? (Ag Facts)
An animal nutritionist most often works with agricultural animals on farms, but they might also work at a zoo with wild or exotic animals.1
Most animal nutritionists have a master's or doctorate degree.1
Ruminants do not have top teeth in the front of their mouth (incisors). Instead their gums are very thick and known as a dental pad.2
Background Agricultural Connections
Interest Approach – Engagement
Write the questions: “What do cattle eat?” and “What do pigs eat?” on the board.
Give each student two sticky notes and have them write their ideas on the sticky note and place their answer(s) under the corresponding question.
Review student ideas as a class, rearranging sticky notes to group, sort, and identify themes or ideas.
Help the students understand that animals eat different things due to their nutritional needs, preferences, and their unique digestive tracts.
Inform the students that they will:
investigate the different digestive systems of livestock;
learn how animals have unique nutritional needs; and
discover the responsibilities of an animal nutritionist.
Prior to this activity, cut out one set of the Got Guts? Descriptions for the cow and pig. Draw a large outline of either a cow or a pig on a piece of foam board for each group.
Project the Animal Appetites handout onto a screen. Read the story aloud. Solicit student responses to the included questions.
Tell students that they are going to act as animal nutritionists. Animal nutritionists must have an extensive knowledge of how animals digest food. They use their knowledge to formulate diets for animals. The diets they create must be nutritionally sound, good-tasting, and economical for the ages and types of animals that will use them.
Introduce the term digestive tract. Briefly review the human digestive system and the roles of teeth and the mouth, esophagus, stomach, small intestine, large intestine, and colon in the function of digesting food. Allow students to identify the parts they know, and if possible, the related function. Highlight the following features:
Digestion begins in the mouth. As the teeth tear and chop food, saliva moistens it for easy swallowing.
From the throat, food travels down a muscular tube in the chest called the esophagus. Waves of muscle contractions force food down through the esophagus to the stomach.
The stomach muscles churn and mix the food with acids and enzymes, breaking it into smaller, more digestible pieces.
Digestion continues in the small intestine, a tube-like structure that absorbs nutrients into the bloodstream.
The large intestine’s main function is to remove water and minerals from the undigested matter and form solid waste that can be excreted.
The colon is part of the large intestine. Bacteria in the colon help to digest the remaining food products.
Tell students that they will use household materials to construct models of both monogastric and ruminant digestive systems. Divide the class into groups of five students. Assign each group a cow or pig digestive tract.
Give each group the Pig Digestive Tract or Cow Digestive Tract handout. Distribute foam board, modeling materials (including balloons, tubes, hoses, straws, string, rope, and empty soft drink bottles, chenille stems, milk jugs, and food containers), and corresponding Got Guts? Labels for the cow and pig.
Instruct students to research their assigned animal, using classroom and Web resources, and then create a model of the animal’s digestive tract on the foam board using the labels and materials provided.
Once students have completed their models, display them around the room. Gather students in a location where both cow and pig digestive tracts are visible. Distribute the Got Guts? Descriptions (both pig and cow) to students. Lead students in a review of each digestive tract, using the Got Guts? Teacher Review as needed. Throughout the review, have students place the correct description of each organ on the correct model.
Summarize student learning with a classroom discussion. Include the following points in the discussion:
Monogastric and ruminant digestive systems are different. Monogastric systems have one true stomach, while ruminants have a multi-chambered stomach.
Animals prefer foods that can be easily digested and used by their body. Cattle have ruminant digestive tracts with large microbial populations that allow them to eat complex plant materials. Pigs and humans have monogastric digestive tracts.
Animal nutritionists use their knowledge about animals and their digestive tracts to formulate diets that are nutritionally sound, good-tasting, and economical.
The proper nutrition of livestock animals is a key component of a successful production system. Just like humans, animals that consume the nutrients they need will stay healthy and grow stronger.
Concept Elaboration and Evaluation
After conducting these activities, review and summarize the following key concepts:
Animal nutritionists help farmers and ranchers provide the proper nutrition in order for animals to grow and be healthy.
Animals with a single-chamber stomach are considered monogastrics. Animals with a multi-chamber stomach are called ruminants.
Ruminant animals such as cattle, sheep, and goats can obtain nutrients from food that humans and other monograstrics cannot.
We welcome your feedback! Please take a minute to tell us how to make this lesson better or to give us a few gold stars!
During the Interest Approach — Engagement, solicit student responses using a text message poll such as Poll Everywhere or SMSPoll. Summarize student responses by creating a Wordle.
Have students choose a livestock animal to research and design a digestive model. Compare the digestive systems of a variety of animals including llamas, sheep, goats, cattle, horses, and pigs.
Students create a diagram of the selected digestive system before working on model. Graphic organizers are a means of introducing and assessing concepts in a manner that encourages meaningful learning.
The activities in this lesson employ group work and cooperative learning. These activities provide opportunities for students to exchange, write, and present ideas. Students use a variety of skills that work together to increase understanding and retention.
Research the educational background and skills required to be an animal nutritionist.
Research the length of animal intestines. Use rope to model and compare the different lengths. Discuss why these differences might exist.
Use diagrams to compare the human, cow, and pig digestive systems. Challenge students to consider which animal humans are most similar to and form an expository response.
Compare the teeth of different animals and discuss how they are designed to break down specific foods. Introduce the terms carnivore, herbivore, and omnivore. Sort the teeth based on the animal’s primary food sources and observe similar characteristics.
This lesson was funded in 2012 by the United States Department of Agriculture’s National Institute of Food and Agriculture through the Secondary Education, Two-Year Postsecondary Education, and Agriculture in the K-12 Classroom Challenge Grants Program (SPECA). Images submitted by California Foundation for Agriculture in the Classroom.
Executive Director: Judy Culbertson Illustrator: Erik Davison Layout and Design: Nina Danner