Dairy Sustainability and Science

Dairy Sustainability and Science

Target Grade Level / Age Range:

3rd Grade

Estimated Time:

Two 45 minutes class periods

Virtual Learning:

Use this document to convert the lesson into a virtual learning module for your students. Use the steps outlined to create the different elements of a Google Classroom or other online learning platform. You can also send the steps directly to students in a PDF, present them in a virtual meeting, or plug them into any other virtual learning module system.

Purpose:

Students will identify aspects of raising dairy cattle and producing milk products that are done in an economically, environmentally, and socially sustainable way.

Materials:

  • My Family’s Dairy Farm book by Katie Olthoff
  • Journal or notebook for each student
  • Pencil or other writing utensil for each student
  • Paper

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

Vocabulary  

  • Sustainability – Doing things in a way that reduce negative impacts on the economy, environment, and society.
  • Heat stress – Cows begin to experience heat stress at much lower temperatures than humans. In general, mild heat stress starts around 72°F with 50% humidity. High-producing cows eat more and generate more heat. They can begin to experience heat stress in well-ventilated barns at air temperatures as low as 65°F.
  • Efficiency – The work performed compared to the total energy expended.
  • Udder – Mammary gland of female cattle having four teats and hanging between the hind legs of the animal.
  • Natural selection – Process where organisms that are better adapted to their environment tend to survive and produce more offspring.
  • Artificial selection – Process by which humans use animal breeding to selectively develop particular traits (characteristics) by choosing which males and females will sexually reproduce and have offspring together.
  • Butter fat – Or milkfat is the fatty portion of milk. Milk and cream are often sold according to the amount of butterfat they contain.

Background – Agricultural Connections

The following information is an excerpt from the Animal Agriculture Alliance (source: https://animalagalliance.org/separating-cows-and-calves-the-real-story/).

COWS AND CALVES ARE DIFFERENT THAN PEOPLE

There are two main reasons why newborn dairy calves don’t stay with their mothers: for their safety and their health. Cows do not exist in a family unit like most people do. They are herd animals, meaning that they are most comfortable with other cows their age and their size – their herd-mates.

COW INSTINCTS

When a cow has a baby, her herd instinct doesn’t just disappear so that she can fulfill the joys of motherhood. For the first hour or two after the calf is born, there is a clear connection between mom and baby. At my family’s dairy farm, we keep the calf with its mother for this part. The mother licks off her baby, which aids in stimulation and getting the calf up and moving. However, after this initial period, the cow becomes increasingly anxious. She wants to be with her herd mates. Cows are not big fans of change, and I think that we can all agree that giving birth is a pretty big change.

This anxiety puts the calf in severe danger. The cow often forgets about her calf. She walks or runs around, searching for her herd-mates and becomes extremely stressed. This can lead to the calf getting stepped, sat on, or injured in a variety of ways.

The average adult dairy cow weighs about 1,500 pounds, while calves are born weighing between 60-90 pounds. Speaking from my own experience, once a calf has been crushed or stepped on by her exponentially larger mother there is not much we as dairy farmers or even veterinarians can do. It is heart wrenching and terrible to see this happen, and far too regular when calves are left with their mothers for too long.

IMMUNE SYSTEM HEALTH OF CALVES

Here, we circle back to the fact that humans and cows are different, especially when it comes down to biology. Human mothers have a different type of placenta–the sac around the fetus–than bovines. And all of the complicated biology of different placenta types boils down to this: when a human baby is born, it already has an immune system with a semi developed immune response. It may be immature, but it’s there. When calves are born, they do not have an immune response to fight off infection.

This causes them to be at a much greater risk for just about everything found outside of their mother’s uterus. Their mother, however, will produce a special milk called colostrum that will (ideally) contain everything the calf needs to start its immune system. But, if the calf tries to nurse off of the cow it can be put at risk.

First, cows are sometimes not the cleanest animals. As dairy farmers we can give them clean beds to lay in, clean their barns two to three times a day and the list goes on and on. The bottom line is, if they want to lay in the dirtiest part of the barn, they can and they will, and they often do. And if the baby calf nurses on a dirty teat before it’s fed colostrum, it could get very sick.

Second, if the calf is suckling, we have no way of knowing if the calf is actually getting quality colostrum, or any colostrum at all. Sometimes cows get sick after giving birth, and that could affect the quality of her colostrum.

MISCONCEPTIONS ABOUT COW/CALF SEPARATION

Finally, I want to address one of the most common misconceptions I hear about why the cow and calf don’t stay together: “if they don’t separate them the calf will drink all of the milk and there won’t be any for them to sell.”

Calves get fed milk or milk-replacer. Milk-replacer is the equivalent of feeding your baby formula instead of breast milk – it’s a personal choice. Cows naturally make more milk than a calf will drink on its own, so the choice to feed replacer versus milk is one made by each individual farm.

THE BEST OF BOTH WORLDS

The bottom line is things can and often do go wrong when the calf is left with the cow. But dairy farmers are trained to be good caretakers to their animals, including the babies. That means that we feed them from a bottle or bucket to make sure they drink their milk and that it comes from a clean place. We are also able to monitor them very closely until their immune system develops, and continue to do so as they get older.

The dairy farmer’s primary job is to keep cows well cared for and healthy. Cows that are not taken care of don’t produce quality milk, so it really is in our best interest to have the cow’s best interest in mind. Calves are the future of every dairy farmer’s herd. So, the same concept applies. Healthy calves grow up to be healthy cows. Caring for the calves ourselves prevents them from being injured by their mothers and enables us to care for them in a controlled environment.

Calves and cows are separated because it is best for both their health and safety. It allows the cow to return to her happy place – her herd – and gives the calf an opportunity to begin its life with its best hoof forward! We, the farmers, can make sure the calf gets clean and nutritious milk. Farmers can tell if the calf gets sick and give it the best care possible. We can do all this while providing a high quality, all natural, nearly perfect food.

SUSTAINABILITY: The following is an excerpt on sustainability from Undeniably Dairy found here:

All food production comes with an environmental footprint. Responsible food production works to minimize that footprint. Dairy farmers constantly innovate to produce the same amount of food using fewer natural resources, yet still provide all the same great nutrients. Thanks to increasingly modern and innovative dairy farming practices, the environmental impact of producing a gallon of milk today involves 30% less water, 21% less land, 21% less manure and a 19% smaller carbon footprint than it did in 2007.

U.S. dairy contributes 2% of all U.S. GHG emissions, and the dairy community is committed to conserving natural resources and making further progress. Together, U.S. dairy will build on its longstanding commitment to continuous environmental improvement, embrace new technologies and build economically viable pathways to environmental solutions. 

SELECTIVE BREEDING: The following is an excerpt from here

Natural selection explains how evolution occurs. Different varieties of plants and animals with desired characteristics can be developed by selective breeding.

Interest Approach – Engagement

Capture student attention and ask them what kinds of things make them comfortable when watching a movie or TV. Possible answers might be big fluffy pillows, soft couch, a bowl of popcorn, or a bowl of ice cream, something to drink like a glass of milk, a nice cool room in the summer or a nice warm room in the winter, a blanket to cover up with, or a fan to cool down with. Write student responses on a large writing surface.

Ask students to think what things might make a cow comfortable. Encourage them to think about their own responses and what things might be similar with a cow. Possible answers might include a soft bed, access to good food, access to clean water, shade and a fan to stay cool in the summer, shelter to stay warm in winter, and maybe a good backscratcher. Write these responses on a large writing surface.

Next ask students if they do chores or homework better when they are happy and comfortable or when they are unhappy and uncomfortable. Provide examples. Is it better to shovel snow with or without warm gloves and a warm coat? Is it better to do homework when it is too hot and sweaty or in a nice air-conditioned room? Direct the conversation so students understand that it is easier and better to do chores when they are happy and comfortable.

What job do dairy cows do? Students should come up with the answer ‘make milk.’ Ask them to think about that based on their previous answers. Do cows do a better job making milk when they are happy and comfortable? Students should answer ‘yes.’

Instruct the students that today we will be learning about how to keep cows happy and comfortable so they can make more milk and so dairy farms can be more sustainable.

Procedures

  1. Pass out copies of the My Family’s Dairy Farm book to students or display the digital version on the screen in front of the entire class. Read the book together as a class, assigning different students to read each page. Help students with any unfamiliar vocabulary. More advanced readers can read the supplementary passages at the bottom of each page.
  2. Ask students if they saw anything in the book, in the barn, that was designed to keep the cows comfortable and happy. Possible answers include food, water, soft beds, and big fans (all on p. 4). Other answers might be beds and fans (p. 8-9) and a clean barn (p. 18-19).
    1. Explain to students that they will become the teacher for a moment. They need to explain why a barn is an ideal habitat (or location) to raise dairy cattle that allows them to survive well. What evidence do they have to support their ideas?
    2. Instruct students to first write their argument or explanation in their journal or notebook.
    3. Then instruct students to share their explanation with a partner.
  3. Ask students what they think would happen to the cow’s milk production if the cow got too hot or too cold. Based on what they’ve learned so far, students should understand that it is important for the cows to be comfortable and that milk production would decrease if they become uncomfortable and too hot. In fact, heat stress can reduce milk production by up to 50%.
    1. To solidify this idea, watch this video with students: Ensuring Cow Comfort Even in the Hottest Months found at https://youtu.be/8ZvcT9lfV6I.
    2. Facilitate a conversation and ask students to go back to the My Family’s Dairy Farm book. When the environment changes, like when it gets hot in the summer, what solutions did Lucas’s family implement in the barn to help keep cattle cool?
      1. Are these solutions good?
      2. Could other solutions be implemented to keep the cows cool? (i.e. misters)
    3. Remind the students that dairy cattle are more efficient at producing milk when they are comfortable, and efficiency makes the dairy more sustainable.
  4. Open the My Family’s Dairy Farm book to page 5. Have students re-read the bottom of the page about how the newborn calves go to daycare. Share the following information about dairy cattle with students. Students can take notes to help remember.
    1. Cows and calves are different from people. Cows do not exist in a family unit like most people do. They are herd animals, meaning that they are most comfortable with other cows their age and their size – their herd-mates.
      1. For the first hour or two after the calf is born there is a clear connection between mom and baby.
      2. After that the mom wants to get back to the herd and can ignore the calf. The anxiety of the cow not being with the herd can put the calf in danger.
      3. Beef cattle producers have bred their animals selecting for maternal traits. Dairy cattle producers haven’t selected for maternal traits.
    2. There are two main reasons why newborn dairy calves don’t stay with their mothers: for their safety and their health.
      1. Safety:
        1. Adult dairy cows can weigh about 1,500 pounds. Newborn calves are only 60-90 pounds. Calves can be stepped on, kicked, or even crushed by the large mother. Removing them to a different location prevents this danger.
      2. Health:
        1. Calves have weak immune systems when first born. They need to be vaccinated and closely monitored to prevent disease.
        2. They need to be kept away from the mother’s manure which can also carry disease. Dirty teats on the cow’s udder can pass disease to the calf.
        3. They need to be provided with enough colostrum to start its immune system and enough milk after that to get enough nutrition. This can be closely monitored by the farmer.
    3. Beef cattle and dairy cattle are different variations of the same species (Bos taurus). But beef cattle are better mothers to their calves than dairy cattle are. Ask the students to think about why good mothering abilities beneficial for beef cattle but not needed for dairy cattle? (possible answers might include that beef cattle live more of their life in pastures where mothers may need to protect their calves from predators. Dairy cattle are raised in barns and protected by farmers.)
      1. Display a picture of a beef cow and a picture of a dairy cow. Ask students to visually identify other differences between the two. Possible answers might be: beef cattle are more muscular, dairy cattle have larger udders, each have different colored coats or different coloration patterns.
      2. For wild animals we focus on natural selection and traits that provide advantages in surviving, finding mates, and reproducing in nature. Farmers use artificial selection to focus on specific traits. How might beef cattle traits and dairy cattle traits provide advantages in surviving and reproducing in domesticated animals? (Farmers want to select the best beef producers – like the biggest animals. But they also want beef cattle to be good mothers and take care of their young, so they select for that trait. Farmers want to select the best milk producers – like the ones that produce the most gallons of milk or the ones that produce the milk with the highest butter fat content. So, they select the animals in the herd that are best and breed those animals.)
    4. Just like beef cows are different than dairy cows, there are different breeds of dairy cows (all the same species). The most common dairy cow in the U.S. is the Holstein which is known for produce large amounts of milk. Ask the students to review pages 5 and 6 of the My Family’s Dairy Farm book. Ask the students what breed of dairy cattle does Lucas and his family raise? (Jerseys) Why do they raise Jerseys? The higher milkfat is better for making cheese.
      1. Have students review the slides of milkfat percentages in Holsteins and Jerseys.
      2. Is there a similarity between the milkfat percentages in the mothers and daughters in the Jersey cows? Is there a similarity in the milkfat percentages in the mothers and daughters of the Holstein cows?
      3. Is there a difference between the milkfat of the Jersey cows and the Holstein cows?
      4. If a higher content of milkfat is needed to make dairy products like cheese and ice cream, which breed of dairy cow would you select to milk? (Jersey)
      5. What might the Holstein milk best be suited for? (grocery store milk – drinking)
  5. To wrap-up the lesson, work with your school lunch program, Farm to School program, or otherwise independently acquire dairy samples for the students to try. Individually wrapped string cheese or individual serving cups of ice cream work well.
    1. As students are enjoying their treat provide one or more of the following writing prompts for them to write a story or letter about.
      1. Dairy cattle are different than beef cattle. Using the information learned, write a story about all the ways that dairy cattle are different from beef cattle.
      2. Dairy cattle need to be well cared for to be comfortable so they can produce the most milk. Write a story about all of the things that you would do to keep your cows comfortable if you were a farmer.
      3. Imagine you are a dairy cow, write a story about what you do on a daily basis. Be sure to include specifics about how many times per day you get milked.
      4. Dairy farmers take good care of their cows. Write a letter to a dairy farmer to say thank you for taking such good care of their cows and providing milk for treats like cheese and ice cream.
    2. Students can illustrate their stories and if time allows share them with the class.

Did You Know? (Ag facts)

  • 95% of U.S. dairy farms are family owned and operated.
  • No two cows have the same spots. They are unique like a snowflake or fingerprint.
  • Dairy foods provide a powerful nutrient package. Vitamin A, vitamin D, and protein are essential for a heathy immune function and are found in dairy.
  • Here are the 9 essential nutrients found in milk:
    • Calcium – helps build and maintain strong bones and teeth
    • Protein – helps build and repair muscle tissue
    • Vitamin D – helps build and maintain strong bones and teeth
    • Vitamin B3 – used in energy metabolism in the body
    • Vitamin A – helps keep skin and eyes healthy and helps promote growth
    • Vitamin B5 – helps your body use carbohydrates, fats, and protein for fuel
    • Vitamin B12 – helps with normal blood functions and helps keep the nervous system healthy
    • Vitamin B2 – helps your body use carbohydrates, fats, and protein for fuel
    • Phosphorus – helps build and maintain strong bones and teeth and supports tissue growth
  • Dairy provides more than half of the calcium and vitamin D and 18% of the protein consumed by Americans, while the U.S. dairy industry’s greenhouse gas footprint is only about 2% of the U.S. total.
  • Heat stress in dairy cattle can reduce milk production by up to 50%.
  • The average fat content of milk from a Jersey cow is 4.9%. Jersey cow milk also has a high percentage of protein – 3.8%.
  • The average fat content of milk from a Holstein cow is 3.7% with a protein percentage of 3.2%.

Extension Activities

  • Present students with the We Will Milk Cows (We Will Rock You Parody) from the Peterson Farm Bros. Have students pick a favorite song and try to rewrite the lyrics of that song based on what they’ve learned about dairy cattle from this lesson or from the My Family’s Dairy Farm book.
  • Have students take a virtual field trip of a dairy farm by watching this video or this video or arrange for a live FarmChat® virtual field trip.
  • Walk students through the Online Farm Experience from Midwest Dairy or instruct them to complete it independently. Use some of the questions from the Discussion Guide to test what they learned.
  • Share the Iowa Dairy Farms, Then & Now: Innovation, Conservation and Dedication infographic with students. Have them write a story about a dairy and try to include one or more of the facts from the infographic in their story. Other state specific info graphics available here.

Suggested Companion Resources

Sources/Credits

Author(s)

Will Fett

Organization Affiliation

Iowa Agriculture Literacy Foundation

Agriculture Literacy Outcomes

  • T1.3-5.a. Describe similarities and differences between managed and natural systems (e.g., wild forest and tree plantation; natural lake/ocean and fish farm).
  • T2.3-5.e. Understand the concept of stewardship and identify ways farmers/ranchers care for soil, water, plants, and animals.
  • T4.3-5.c. Identify examples of how the knowledge of inherited traits is applied to farmed plants and animals in order to meet specific objectives (i.e., increased yields, better nutrition, etc.).

Iowa Core Standards

  • 3-LS4-2. Use evidence to construct an explanation for how the variations in characteristics among individuals of the same species may provide advantages in surviving, finding mates, and reproducing.
  • 3-LS4-3. Construct an argument with evidence that in a particular habitat some organisms can survive well, some survive less well, and some cannot survive at all.
  • 3-LS4-4. Make a claim about the merit of a solution to a problem caused when the environment changes and the types of plants and animals that live there may change.*
  • 3-LS1-1. Develop models to describe that organisms have unique and diverse life cycles but all have in common birth, growth, reproduction, and death.
  • 3-LS3-1. Analyze and interpret data to provide evidence that plants and animals have traits inherited from parents and that variation of these traits exists in a group of similar organisms.
  • SS.3.13. Identify how people use natural resources, human resources, and physical capital to produce goods and services.