Ag in Action: Learning with Pigs – Then and Now

Target Grade Level / Age Range:


Estimated Time:

                35-50 minutes depending on depth


In this lesson students use artifacts to investigate past and present pork production. They develop claims backed with evidence of different influences that caused these changes.


  • Livestock veterinarian poster 

Essential Files (maps, charts, pictures, or documents)


  • Piglet: a young or baby pig 
  • Sow: a female pig that has had offspring 
  • Confinement: a modern housing option for pig and poultry production. The system is confined and often has ventilation systems to reduce virus and pest contamination.
  • Hoop barn: also known as a high tunnel or hoop house this is a lower cost housing option for pigs that provides shelter and protection from sun and some elements. 
  • Pasture raised: livestock, such as pigs, that are raised through free range where they forage for their food.  
  • Trough: a long shallow often V-shaped receptacle for the drinking water or feed of domestic animals. 
  • Sty: a pigpen that often has a dirt floor and is outdoors.

Background – Agricultural Connections

Like humans and other animals, pigs have four basic needs—air, water, food, and shelter. Pigs also need social interaction with other pigs, treatment for injuries and diseases, and space to stand, stretch, and lie down1 Pigs raised on farms live in environments that are designed to help farmers meet these needs. Barns protect pigs from weather, disease, and predators. Farmers provide pigs with fresh air, clean water, nutritious food, and shelter. 

Modern Pig Farming: Most modern pig housing includes computer technology. Confinement buildings are the most common way to raise pigs today. These buildings have technology that can be used to help control the temperature inside where pigs live. Pigs are susceptible to heat and cold stress. Because pigs are unable to sweat to regulate their temperature, farmers use fans and misters to help them stay cool in the summer. Heaters or lamps are used to help pigs stay warm in the winter. Pigs also have sensitive skin that is prone to sunburn. Providing shade for pigs is an important part of keeping them healthy and safe. To meet these needs, modern farmers use three common housing techniques for pigs:   

  • Free Range Pigs (Pastured Pork Production): There is not a building structure, the hogs utilize pasture as a feed source but they are not as efficient as ruminants. There are both advantages and disadvantages associated with using pasture for hogs.  
      • Advantages 
        • Outdoor, pasture-oriented production systems open potential niche market opportunities. 
        • Hogs can benefit from the activity and exercise associated with foraging. 
      • Disadvantages 
        • Excessive rooting behavior can result in soil erosion issues. 
        • Hogs can escape from pastures. Hogs escaping from farms has been identified as one of the causes of the growing feral hog problem in many parts of the United States. 
        • Internal parasite issues can be severe on poorly managed pasture systems. 
        • Light-skinned hogs can suffer sunburn while grazing. 
        • Managing pasture takes much time and commitment to make it successful. 

If you decide to use pasture on your farm, you need to be committed to managing the pasture plants and grazing. Pastures can be made up of either perennial or annual plants. A perennial pasture is a long-term investment. It is important to try to prevent rooting damage to perennial pastures to maintain their long-term productivity. Annual pastures will need to be replanted each year. Tillage used to establish annuals can also be used to smooth out fields and reduce bacterial and parasite contamination. Re-establishment adds considerable cost to the use of pasture. 

  • Hoop Barns: Used to finish hogs to market weight, hoop barns are another option for producers to use as a swine production facility. They are lower in cost compared to traditional confinement barns. A hoop barn is a Quonset™-shaped structure with sidewalls 4 to 6 feet high made of treated wood posts and wood sides or concrete. Tubular steel arches fastened to the tops or sides of the posts form a hooped roof, which is covered with UV-resistant, polyvinyl tarp. When used as swine housing, hoop barns have concrete or earthen floors. Buildings with earthen floors have a concrete slab for a feeding and watering area. The floor, except for the feeding and watering area, is deep bedded and cleaned after each group of pigs is marketed.  
    • Advantages (most beneficial for producers who have one or more of the following needs): 
      • Want facilities to match a rapidly changing swine industry. 
      • Need a short-term structure that can be removed after use or that can be adapted for other uses. 
      • Want to keep fixed costs low. 
      • Have limited capital. 
      • Need facilities for groups of 150 to 200+ pigs, which could be impractical for other housing types. 
      • Are not interested in accepting the financial risk associated with a large capital investment. 
      • Prefer to handle solid manure and have the capability to do so. 
      • Have the equipment and land resources to harvest crop residue for bedding. 
      • Prefer a system of production that is less automated and requires different husbandry skills than those needed in confinement buildings. 
      • Believe pigs should be reared in an environment with bedding. 
      • Can be built quickly. 
      • May qualify for some niche market requirements and premium prices. 
    • Disadvantages 
      • Observing animals in large groups is more difficult. 
      • Hoop-housed pigs may use feed less efficiently during cold periods. 
      • During inclement weather, the labor environment is less favorable in hoops than in confinement buildings. 
      • Hoop-raised pigs may be slightly less lean than confinement-raised pigs. 
      • More labor may be needed for hoops than for confinement buildings. 
      • Hoops require large amounts of bedding, and labor needs for harvesting bedding may conflict with the labor needs for harvesting grain. 
      • Raccoons and other animals that can foster farm-to-farm disease transmission may use the bedding storage area for nests. 
      • Excluding birds and other pests that may carry diseases is difficult. 

  • Confinement Building: The hogs are confined in a closed system called confinement buildings. These buildings allow the producer to control many aspects of the building and the environment in which the pigs are living in. They are built with biosecurity practices in mind and work to keep disease out. They are also set up with the latest technology and have close monitoring systems to help the producer monitor the health and feed rations of the hogs. The primary advantages of closed herd systems are tighter control of hog supply and potential reduction in the risk of disease introduction. They remove the risk of disease breaks from each part in the production chain. Some of the disadvantages of confinement operations is that they do require additional management to monitor and care for the hogs inside and with all the advantages and use of biosecurity practices they are a lot more costly. 
    • Advantages 
      • Tighter control of hog supply 
      • Reduction in the risk of disease introduction 
      • Closer monitoring systems 
    • Disadvantages 
      • Require additional management to monitor and care for the hogs inside 
      • With all of the biosecurity protocols they can be a lot more costly 

Past Pig Farming: In contrast, past farmers did not have access to the housing technology we have today. Pigs were often raised in a pasture, outdoor pen, or sty. Colonists in Pennsylvania developed the practice of “finishing” the hogs on corn (feeding them nothing but corn in the few weeks before butchering them). This practice improved the quality of the pork and laid the foundation for the modern pork industry. In the colonial US, hogs were driven to market in large droves over trails that later became routes used by the railroads. 

Hog raising became an important commercial enterprise during the 1800s when the midwest farm regions were settled. The new Erie Canal system gave farmers a way to get their hogs to the cities back east. Farmers started calling their hogs “mortgage lifters” because the profits from their sales helped pay for the new homesteads. 

The hogs would eat corn, grass, clover or even table scraps that would have otherwise become garbage. The word “hogwash,” meaning something that is worthless, came from this practice. In some areas, hogs would be turned out to find their own food. Hogs would roam freely, eating what they could find. This included acorns from the ground or roots, which they dug up with their snouts. On Manhattan Island, New York, the hogs rampaged through grain fields until farmers were forced to build a wall to keep them out. The street running along this wall became Wall Street. 

Most people had pig pens near their homes and fed the hogs just enough to keep them returning home from their daily forage for food. Everybody had a different hog call so that only their pigs responded to their call. These calls might be a high pitched "sooie," a low pitched "wark," or a simple "here pig here." 

In this lesson, students explore current and past housing practices used to raise pigs through images. They draw connections between housing type and impacts weather has on pigs and how this impacts humans. Using their acquired knowledge, students engineer a pig barn that will protect pigs from a flood. 

Interest Approach – Engagement (5-10 minutes)

Prior to class beginning hang up the Housing Then and Now Artifacts around the room. 

  • Hand out a sheet of paper to each student. Have students fold this sheet of paper in half “hamburger” style.  
  • Ask students to label one side, “Modern Farm”. Then instruct students to draw what they think a pig farm looks like today.  
  • Instruct students to label the other side of the paper with “Past Farm”. Have students draw what they think a past pig farm looked like.  
  • Have students get with a partner and share their drawings.  
  • Bring the class back together. On the white board, or on poster paper, create a table with one side labeled “Modern Farm” and the other “Past Farm”. Ask students what key words they could use to describe each. Keep track of these on the board. Once all students have shared, summarize what was discovered.  
  • Optional: Then ask students what questions they have about modern and past pig farming. Have students record at least 3 questions they have on the back of their paper.
    • Have students get into groups of 3-4 and share their questions. From these questions, have students choose 1 they would like to share with the class and instruct them to write that question on the board.  
      • Alternatively, hold a class discussion and record student questions for them.  Most likely, a question from students will be, “What was past pig farming like” and “What does modern farming look like”.  
  • Let students know that today they’ll be investigating modern and past pig farming and housing using images. 


Explore (15-20 minutes)

  1. Hand out the Artifact Journal to students. Give students time to look through the journal and walk them through how they can fill it out. Let students know that the questions in their journal align with the questions at the different artifacts, and that each artifact has a number which corresponds with their journal.  
  2. Set a timer for 15 minutes. Let students take time wandering from artifact to artifact. While students move from artifact to artifact, they will fill out their journal. 
    • Alternatively, split students into groups. In their groups students will divide the artifacts out, making sure that each artifact is investigated by at least one person. Students will then report back to their group what they discovered about the artifact.  

Explain (10 minutes)

  1. After 15 minutes, bring students back together to share what they found as a large group.  
  2. Bring students' attention to what they mentioned at the beginning. Ask students if there’s anything they’d like to add to these lists.  
    • Optional: Students reflect on the questions they had at the beginning and identify if they were able to answer them now. Lead a class discussion on which ones they are able to answer and which ones they are not. Let students know that the questions they haven’t been able to answer they’ll be able to come back to.  
  3. Pose the question, why do you think modern pig production is so different from how pigs were raised? 
    • Help students make connections to concepts of larger herd size, disease, weather elements and pig death, fewer people living on farms, family dynamics have changed. This question will prepare students for the elaborate portion. 

Elaborate (10 minutes)

  1. Students apply what they learned through discussion and investigation to answer the focus questions on the back of their journal.  


  1. After conducting these activities review and summarize the following key concepts encouraging students to pull information that they wrote in the Elaborate section:  
    • Agriculture has changed over time.  
    • Livestock housing protects pigs from Earth processes. 

Extension Activities

  • Pose an engineering challenge to students: Show students the picture of farmers moving their pigs during a flood. Ask students what problem the farmers are having. Help guide them toward the problem that flooding can affect livestock housing. Flooding has become more frequent in recent years and farmers are beginning to think ahead and plan for these types of events. When flooding occurs, manure from pits can impact waterways. This can cause fish kills (when algae growth causes oxygen levels in water to decrease and many fish die). Challenge students to think like farmers and engineers. Have them design new pig housing or manure pit that can reduce the effects of flooding on pig farmers. (see Pig Housing and Facility Design for more ideas)
  • Explore the structures of a pig with the Ag in Action - Learning with Pigs - Structures and Functions lesson

Did you know? (Ag facts)

  • Iowa ranks number one in pork production. 
  • Pigs are raised for more than meat. They help provide medical supplies and even school supplies! Learn more about pig byproducts with this resource.

Suggested Companion Resources



Cathryn Carney 

Organization Affiliation

Iowa Agriculture Literacy Foundation

Agriculture Literacy Outcomes

  • T5.3-5. c. Explain how agricultural events and inventions affect how Americans live today (e.g., Eli Whitney - cotton gin; Cyrus McCormick - reaper; Virtanen - silo; Pasteur - pasteurization; John Deere - moldboard plow.
  • T5.3-5.f. Understand the agricultural history of an individual’s specific community and/or state

Iowa Core Standards

  • Science
    1. 4-ESS3-2. Generate and compare multiple solutions to reduce the impacts of natural Earth processes on humans.* (if extension is completed) 
  • Social Studies
    1. SS.4.25. Analyze the impact of technological changes in Iowa, across time and place. 
    2. SS.4.26. Explain how Iowa’s agriculture has changed over time.