Lesson

NOTE: While we create most lessons on the Growing Math site ourselves, we do include links to other lessons that are exemplary in their cross-curricular, standards-based design. This lesson is one of two “lessons we love” from Discover Dairy. The entire 14-page guide with two lessons can be downloaded here, including reading passages, lab assignments and answer keys.

You can also go to the Discover Dairy site, which requires a free registration and login to download individual parts of the lesson and see the other lessons they have available.

Read a passage on the life cycle of a dairy cow

You’ll find this on page 14 of the handout linked above or download both reading assignments here (it’s only two pages) or copy the link to assign in your Google classroom to read on line.

Class Discussion on Life Cycle

Using the discussion questions on page 4 of the complete lesson plan, discuss the dairy cow life cycle with students based on their knowledge from the reading.

Lab Exercise #2 Feeding a Dairy Cow

Each student or group will need a scale or measuring cup and the following:

• 1 cup spinach
• Baby or whole carrots
• 1 cheese stick
• One 12 oz. cup of orange juice

Distribute the materials needed and the lab assignment (pages 11 and 12 of the complete lesson plan or you can link directly to those here, if you want to assign in Google classroom or other management system. Note that link includes both labs 1 and 2.) Lab explanation from page 5 of the complete lesson plan.

Teachers should explain that a healthy, well-cared-for cow will give more milk. The way farmers care for their cows and how they feed them has helped to increase the amount of milk cows give over the past 50 years.  Just like our diets, a cow’s diet must be balanced based on her stage of life. For instance, a baby calf requires higher energy foods to fuel her rapid growth.  A cow that has just given birth requires higher levels of certain nutrients to replenish her body. Farmers must adjust rations to accommodate those needs.  Farmers work closely with an animal nutritionist and use a variety of feed products to balance cows’ diets to meet their precise nutrient needs using a variety of feed products.  Farmers use a large feeding scale to make sure each cow gets the right amount of each feed. Those feeds are blended together to provide a balanced diet called a Total Mixed Ration (TMR). During the lab, students should use the carrots, celery, cheese and orange juice to balance a diet to meet the required nutrients listed on the lab worksheet. They should use a weight scale to measure the right amount of each feed. If they don’t have a weight scale, they can use measuring cups to determine the amount. Complete the ratios in the worksheet.

– Discovery Dairy

Answer keys for this lab exercise as well as for the lab for the selective breeding lesson can be found here.

Review and Summarize Dairy Cow Life Cycle: What We’ve Learned

Review questions and summary can be found on pages 5 and 6 of the complete lesson plan.

ASSESSMENT

This lesson includes three types of assessment – the initial class discussion gives an estimate of the general class understanding of the dairy cow life cycle. The lab provides individual student data on mastery of both the science and math concepts. The concluding review questions can be poised to the whole class or given to students as a quiz.

Related lesson

Discover Dairy: Selective Breeding