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Lesson Plan

The Environmental Footprint of Livestock

Grade Level
9 - 12
Purpose

Explore modern livestock farming practices and the ecological footprint of meat, milk, and egg production. Evaluate the contributions of the livestock industry and weigh the challenges related to environmental and economic sustainability of animal-source foods in comparison to plant-source foods. Grades 9-12

Estimated Time
2 hours
Materials Needed

Engage:

Activity 1: Exploring How Livestock Are Raised

Activity 2: Comparing the Environmental Footprint of Plant-Source and Animal-Source Foods

  • The Environmental Footprint of Livestock slide deck, continued
  • The Environmental Footprint of Livestock handout, continued
  • Livestock Flow Chart*, 1 copy per student

Activity 3: Livestock and the Environment—On the Flip Side

  • The Environmental Footprint of Livestock slide deck, continued
  • The Environmental Footprint of Livestock handout, continued
  • On the Flip Side cards*

*These items can be purchased in the classroom-ready Environmental Footprint of Livestock Bundle from agclassroomstore.com.

Vocabulary

animal husbandry: the science of breeding and caring for farm animals

animal welfare: as defined by the American Veterinary Medical Association, a human responsibility that encompasses all aspects of animal well-being, including proper housing, management, disease prevention and treatment, responsible care, humane handling, and, when necessary, humane euthanasia

best management practices: methods that can improve efficiency, optimize resources, and prevent or help reduce pollution

byproduct: an incidental or secondary product made in the manufacture or synthesis of something else

Concentrated Animal Feeding Operations (CAFOs): an intensive animal feeding operation with over 1,000 animals for at least 45 days

euthanasia: a Greek term meaning "good death" which, in the context of animals, means a painless death is induced to relieve suffering

feed crops: crops produced primarily for consumption by animals

livestock: farm animals (such as cows, horses, and pigs) that are kept, raised, and used by people

Did You Know?
  • Pork is the most consumed animal protein across the world.1
  • Livestock produce more than meat, milk, and eggs. They also provide byproducts such as leather, pet food, violin strings, glycerin, and much more.1
  • Growth and transformation of the livestock sector offers substantial opportunities for agricultural development, poverty reduction, food security gains, and improved human nutrition.2
Background Agricultural Connections

Livestock provide many benefits to the modern world. The nutrients provided by animal-source foods like meat, milk, and eggs are challenging to duplicate with plant-source foods alone. It is especially difficult in some geographic regions of the world where some foods cannot be grown due to an inadequate climate or natural resources. Additionally livestock provide numerous byproducts that we use every day of our lives. That said, raising livestock also raises ethical, environmental, and health-related considerations. Balancing the contributions of livestock with these concerns is a topic of ongoing discussion and innovation that is addressed in this lesson plan and associated activities.

Environmental Footprint of Food

The ecological food footprint, often referred to as the environmental footprint of food, takes into account various factors that measure the environmental impact of producing, processing, transporting, and consuming food. Some of the key factors considered in the ecological food footprint include:

  • Land Use: The amount of land required for agricultural production, including crop cultivation, grazing, and feed crop production. This accounts for both direct land use and land used for feed production. It can also include the impact of agricultural practices on soil health, erosion, and degradation.

  • Water Use: The amount of water required for irrigation, animal drinking, and processing throughout the food supply chain. This includes both direct water use and the water embedded in food production. The pollution of water bodies from nutrient runoff, pesticide residues, and other contaminants associated with agricultural activities should also be evaluated.

  • Greenhouse Gas Emissions: The emissions of greenhouse gases such as carbon dioxide, methane, and nitrous oxide associated with food production, transportation, and processing. These gases contribute to global warming and climate change.

  • Energy Consumption: The energy required for various stages of food production, including planting, cultivation, harvesting, processing, transportation, and storage.

  • Waste Generation: The generation of waste materials along the food supply chain, including packaging waste and food waste.

  • Inputs: The ecological footprint of resources used to produce inputs like fertilizers, pesticides, and machinery for food production. Includes the use of pesticides, herbicides, fertilizers, and other chemicals in food production that can affect soil and water quality and impact ecosystems.

  • Transportation: The energy and emissions associated with transporting food from production sites to processing facilities, markets, and consumers.

These factors collectively contribute to understanding the overall environmental impact of food production and consumption. Life cycle assessment (LCA) is a common method used to quantify the ecological food footprint by considering all stages of the food supply chain. Life cycle assessments could be made for all consumer items. Efforts to reduce the ecological food footprint involve adopting sustainable farming practices, improving resource efficiency, reducing waste, and promoting responsible consumption patterns.

Contributions of the Livestock Industry

The livestock industry encompasses various aspects of animal agriculture that involve the raising, breeding, and utilization of animals for various purposes. This industry provides a wide range of products and services that are essential for human consumption, economic growth, and other applications. Livestock animals provide the following:

  • Meat: The primary purpose of livestock in many societies is to produce meat for human consumption. This includes beef, pork, poultry (chicken and turkey), lamb, and other types of meat. Meat serves as a significant source of protein, vitamins, and nutrients in human diets.
  • Dairy: Livestock, particularly cattle, are raised for dairy production, providing milk, cheese, yogurt, butter, and other dairy products. Dairy products are rich in calcium, protein, and other nutrients and are widely consumed around the world.
  • Eggs: Poultry, such as chickens, are raised for egg production, supplying a vital source of protein and nutrients to diets globally.

While meat, dairy products, and eggs are the primary products produced by livestock, there are also many secondary, or byproducts as well. The livestock industry provides leather, fertilizer, pet food, fiber, and ingredients used in wax paper, crayons, margarine, paints, rubber, candles, soaps, cosmetics, shaving creams, gelatin, and more. Livestock also provide employment and economic opportunities and play important roles in some cultural and traditional practices, rituals, and ceremonies throughout the world.

Concentrated Animal Feeding Operations

One specific concern of some about the livestock industry is CAFOs, or Concentrated Animal Feeding Operations. They are large-scale livestock production facilities where animals (typically cattle, poultry, or swine) are confined in relatively high numbers. The primary purpose of a CAFO is to maximize efficiency by caring for a large number of animals in one space. This practice allows for more controlled feeding, disease management, and waste disposal, but it has raised environmental and animal welfare concerns. Animals in CAFOs are typically housed in close quarters, often in enclosed buildings, pens, or cages. This confinement helps streamline management practices but can lead to concerns about animal welfare due to limited space and restricted movement compared to animals living in the wild. CAFOs house a significant number of animals. This high density can result in concentrated waste production and increased risks of disease transmission among the animals. CAFOs use intensive feeding practices to promote rapid growth and efficient production. Animals are often fed specialized diets to maximize weight gain, milk production (in the case of dairy CAFOs), or egg production (in the case of poultry CAFOs). One of the significant challenges with CAFOs is the management of animal waste. The large volume of manure generated in these operations can lead to pollution of soil and water if not properly handled. Manure runoff can contribute to nutrient pollution, including nitrogen and phosphorus, in nearby water bodies. Due to their scale and waste management practices, CAFOs have faced criticism for potential environmental impacts. These concerns include water pollution, air emissions (such as ammonia and hydrogen sulfide), and the contribution to greenhouse gas emissions. CAFOs are subject to regulations at the federal and state levels in the United States. The U.S. Environmental Protection Agency (EPA) has established rules under the Clean Water Act to manage the potential water pollution from CAFOs. States may also have their own regulations. It's important to note that there are ongoing discussions and debates about the benefits and drawbacks of CAFOs, including their impact on the environment, animal welfare, and the overall sustainability of the livestock industry. Some efforts focus on implementing best management practices to mitigate the negative effects associated with CAFOs.

Do we really need livestock?

If we did not raise livestock, several aspects of our world would be significantly different. Livestock play a crucial role in various aspects of human life, culture, economy, and ecology. 

  • Food Supply: Without livestock we would see a large nutrient deficit in the global food supply. Livestock provide a substantial amount of protein, including meat, dairy, and eggs. Without livestock, we would need to find alternative sources of protein to meet nutritional needs. A reduction in animal-based protein could lead to shifts in dietary patterns. Plant-based protein sources might become more dominant, affecting cultural practices, cuisines, and eating habits. These dietary shifts could be feasible in developed countries, but developing countries would find it challenging—if not impossible—to replace the nutrients with plant-source foods given their limitations.
  • Economy: The livestock industry contributes significantly to the global economy, including farming, processing, distribution, and related industries. A lack of livestock would lead to economic changes, affecting livelihoods and jobs in rural areas. Livestock farming supports the livelihoods of millions of people, especially in rural areas. A shift away from livestock could impact these communities economically and socially.
  • Agricultural Practices and Soil Nutrients: Livestock contribute to sustainable agricultural practices through manure for fertilization, rotational grazing, and weed control. Without livestock, agricultural systems would need to adapt to alternative methods of improving soil fertility through the application of soil nutrients (fertilizers). Certified organic farms would lose their primary source of fertilizer.
  • Culture and Traditions: Livestock are integral to many cultural practices, traditions, and cuisines around the world. Their absence could lead to shifts in cultural identity and practices. Many products beyond food, such as leather, wool, and gelatin, are derived from livestock. Their absence would require alternative materials or production methods. 
  • Ecosystem Maintenance: Livestock can provide ecosystem services, such as grazing for fire prevention and habitat management. The absence of livestock might impact certain ecosystems and their biodiversity. Livestock farming contributes to land use patterns. Without livestock, there might be changes in land management practices, with potential implications for deforestation, reforestation, and habitat preservation. 

It's important to note that the absence of livestock would lead to complex changes across various sectors. While there are discussions about reducing the environmental impact of livestock farming and improving animal welfare, a complete absence of livestock would have wide-ranging implications that would need to be addressed. Proper management, rather than elimination, typically offers more sustainability.

Engage
  1. Project the attached slide deck, The Environmental Footprint of Livestock. Ask students what kind of supplies they need to bake cookies. Students should easily list food ingredients such as flour, sugar, or eggs (slide 2). If they stop there, prompt them to think about measuring cups, bowls, an electric mixer, and an oven. Prompt even further to ask what is needed for the oven to work (electricity or natural gas) or what was used to make the plastic or metal mixing bowls (ore and/or fossil fuels mined from the earth). (slide 3)
  2. Instruct students to stay in a similar frame of thought and think about what is needed for farms to be able to produce the food we eat. Make a brainstorm list on the board of what your students can identify using their prior knowledge. (slide 4)
  3. Give each student one copy of The Environmental Footprint of Livestock handout. (They will use this handout throughout the lesson for notes.)
  4. Watch, What contributes to the environmental impact of food? Add to the brainstorm list as students watch the video clip. 
  5. Ask students, "Do you think some foods require more natural resources to produce than others?" Explain that you will be exploring the environmental footprint of food with a specific look at the difference between plant-source and animal-source foods. (slide 6)
Explore and Explain

Activity 1: Exploring How Livestock Are Raised

  1. Begin by defining livestock. (slide 7) Students should be able to recognize the difference between a wild and domesticated animal as well as the difference between pets and livestock.
    • Note: In some cases, birds such as chickens and turkeys can be referred to as poultry rather than livestock. In this lesson, poultry are included under the umbrella term of livestock because they fit in the overall evaluation of plant-based vs animal-based foods.
  2. Introduce the following questions that students will be exploring:
    • What is the life cycle of each livestock species?
    • What products do they contribute to our society?
    • What natural resources are required in the farm-to-fork process?
  3. Use the Livestock Production Systems e-magazine (digital or print version) to guide students in exploring the common farm-to-fork processes of raising livestock in the United States. Use one of the following strategies to match the needs of your class.
    • Option 1: Divide the class into six groups. Assign each group one livestock species to study. Have each group share with the class what they learned. Watch the virtual field trips and video clips after each group shares.
    • Option 2: Print the cards for students to read independently. Watch the virtual field trips and videos as a class.
    • Option 3: Share the information cards with students digitally. Assign students to read through the cards. They should watch each virtual field trip and the hyperlinked videos.
  4. Once students have explored each livestock species using the Production System e-magazine, ask students to share their reflections about what they learned. Conversation will vary based on your student's prior exposure to farms and agriculture. Consider the following questions to prompt discussion:
    • What did you see (from the videos) or read (from the text) that was new to you?
    • What information was already familiar to you?
    • What environmental impacts and concerns are associated with raising livestock?
  5. Watch the video Concentrated Animal Feeding Operations. Explain that the video will describe a term the EPA (Environmental Protection Agency) uses to classify farms so they can be regulated and monitored if they pose a risk of polluting waterways. 
  6. Following the video, ask the following questions: (slides 10-12)
    • Why did the EPA create the term and parameters for CAFOs? (To identify farms that pose a risk to local waterways. By defining and categorizing farms by their size, local government organizations can monitor the farm's management systems and require operating permits and oversight to diminish and prevent water pollution.)
    • What is the primary byproduct of livestock that can pollute water sources? (Manure. This can be in solid form, or liquid. Farms large enough to require a manure management system do so through a variety of systems including manure lagoons, anaerobic digesters, land application, and other methods.)
    • How does the density of animals in a given space correlate to the risk of damaging or polluting natural resources? (A higher concentration of animals means a higher concentration of manure. Manure in the wrong place or in excess is a pollutant.)
Teach for Clarity

Evaluations of livestock production styles, especially in reference to Concentrated Animal Feeding Operations (CAFOs), includes discussion about environmental impact, human health, and animal welfare. Due to the complexity of these topics, this lesson focuses solely on the environmental impact of livestock. Help keep students focused and direct their comments accordingly to foster a focused conversation.

Activity 2: Comparing the Environmental Footprint of Plant-Source and Animal-Source Foods

  1. Return to the overarching question introduced in the Engagement section of the lesson, "Do some foods require more natural resources to produce than others?" (slide 13) Allow students to consider this question again and offer their ideas that developed from their exploration of how livestock are raised (from Activity 1).
  2. Give each student a copy of the Livestock Flow Chart. As the students follow the cycle of production for each species, have them highlight steps along the path that require natural resources and contribute to the environmental footprint of the product(s) the animal produces. (Slides 14-16 will guide students in the process. Use the slides for lower-level learners. Upper level learners should be able to identify some without the guidance of the slides.)
  3. Provide a comparison of environmental impacts of plant-source foods and animal-source foods using slides 17-19. Point out the second layer of impacts on slide 19 to help provide an illustration to students about the additional input required to raise animals that produce meat, milk, and eggs to eat. 
  4. Conclude with students that animal-source foods have two layers of environmental impact—the production of crops to feed livestock and the impact of the livestock themselves. In comparison, plant-source foods have a smaller environmental impact (per unit of food produced) than animal-source foods.

Activity 3: Livestock and the Environment—On the Flip Side

  1. With the conclusion that animal-source foods have a larger environmental footprint than plant-source foods, ask students to brainstorm questions they could explore to determine if an omnivore diet can be environmentally sustainable. Examples of questions could include:
    • For the sake of the planet, should we shift to a vegan diet completely?
    • If we stopped eating meat, milk, and eggs, what unintended consequences could we see in the big picture of our society and cultures?
    • How can technology help mitigate negative environmental impacts from livestock production?
  2. Explain that these are complex questions that warrant the exploration of multiple perspectives.
  3. Divide your class into six teams or small groups of students. 
  4. Give each group one set of the Livestock and the Environment—On the Flip Side cards. Explain that each of the cards describes one topic for consideration to evaluate the environmental impact of raising livestock in our food system. One side of the card describes one perspective on the topic. The other side of the card contains another perspective. Students should consider one perspective, then look on the 'flip side' and consider the other perspective. Instruct students to leave the side of the card they relate with best facing up.
  5. After all five cards have been reviewed and placed, each student group should review the "Consider This" cards. These cards help illustrate the connections that exist between livestock and factors related to traditions, cultures, nutrition, and geography. They also introduce a few technologies that help mitigate the negative environmental impact of livestock in our food system. 
  6. Conclude the activity with a discussion about the complexity of the issue of livestock and the environment.
    • Does animal-source food require more of Earth's resources than plant-source food? (yes)
    • Does this issue include both science and social factors? (yes)
Elaborate
  • Read the article, 5 Nutrients Meat Has that Plants Don't from Dirt to Dinner.
  • Study further about the size of farms in the U.S. using the lesson plan, The Big Deal About Big Ag.
  • Have students study specialty livestock like deer, elk, and reindeer that are raised on farms. Is there a difference in the ecological footprint of these species in the wild compared to raising them on farms?
Evaluate
  1. Introduce the economic concept of an opportunity cost. Illustrate an opportunity cost in a way that helps students see that selecting one choice or another comes at a cost.
  2. Provide relatable examples of purchasing decisions individuals might make:
    • When purchasing gas we choose regular higher grade gas. Our choice will depend on the type of vehicle we drive and possibly our education about the impacts of each grade of gas. We determine if the more expensive gas is worth the added price to us.
    • When we purchase shoes, we determine how much we will spend. Some name-brand shoes cost more, but may hold up longer. There may also be some cases where a cheaper shoe will suffice. Individuals choose according to their knowledge and circumstances.
    • When planning a vacation, a resort vacation a distance from home is going to cost much more than a local stay-cation. An individual may not have enough money for an expensive vacation and choose a local vacation out of necessity. Another individual may prioritize a destination vacation and work toward the added resources it takes to have the experience. Some people enjoy traveling, others would rather not. Each choice has opportunity costs and benefits.
  3. Relate the concept of opportunity costs to our food. Everything we eat is at a cost to our environment as well as our budget. We "pay" by using the Earth's natural resources. Associated to the costs are benefits that relate to our nutrition, health, economy (jobs), culture, values, and other factors.
  4. With information from many sides, have students write a conclusion and action statement regarding what they believe is the best way forward to balance the cultural, nutritional, and economic needs of our society with the environmental impact of livestock.
  5. Review and summarize the following key concepts:
    • Modern livestock farms vary in size from small to very large. Many large-scale farms operate with sophisticated technology to automate tasks such as feeding, watering, and waste removal.
    • The cost of livestock production and the cost of food at the grocery store are correlated. Some livestock production styles have higher production costs than others.
    • CAFO stands for concentrated animal feeding operation. Farms defined as CAFOs are regulated and monitored to mitigate the potential pollution of local waterways.
    • Animal-source foods have a larger environmental footprint than plant-source foods (per unit of food produced).
Teach for Clarity

The goal of this lesson and the critical thinking activities it contains is not to determine that raising livestock for food is strictly "good" or "bad" from an environmental perspective. Instead, students should be able to use higher-level thinking and evaluate elements from a variety of viewpoints and perspectives to see the benefits and trade-offs of an omnivore diet in comparison to a vegan diet in reference to environmental health and human impact on our Earth and natural resources.
Sources
  1. Ag Daily: 7 things you may not know about livestock
  2. FAO of the United Nations: Animal Production
  3. 5 Nutrients Meat Has that Plants Don't
Recommended Companion Resources
Author
Andrea Gardner
Organization
National Center for Agricultural Literacy
Powered by the National Agricultural Literacy Curriculum Matrix (agclassroom.org)