Activity 5.3.2 – What’s in it for me?

Purpose

You have researched the food pyramid and are now able to recognize the nutrients in many common foods you eat. You may call a cheeseburger a complete meal. You receive a serving of grains from the bun, vegetables from the lettuce, tomato, and onion, milk from the cheese, meat from the burger, and maybe even an oil from the mayonnaise. From this example, you can recognize where you get your essential nutrients – carbohydrates, protein, fat, and maybe a few vitamins and minerals. However, what specific nutrients do animal feeds provide?

Livestock feeds are more commonly classified into three categories – roughages, concentrates, and supplements. These categories are based on the fiber content and nutrient density of the feed. Roughages are commonly high in fiber and low in energy. Concentrates are typically low in fiber and high in energy, protein, or both. Supplements are also used in the livestock industry and supply specific nutrients, particularly vitamins and minerals that may be deficient in the diet. Feed additives may also be used to modify a diet. How are everyday feedstuffs classified into the nutrient groups?

Equipment

Per student:

· Samples of feedstuffs

· Computer with Internet access

· Pencil

· Agriscience Notebook

Procedure

In this activity, you will be classifying a series of feedstuffs. Some feeds may be used for both human consumption and animal feeding, therefore, you may see foods that are familiar to you. You will complete Parts One and Two by categorizing the feedstuffs into nutrient categories first and feed classifications second.

Part One – Nutrient Categories

In Table 1, classify each feed into the category of nutrient the feed provides. Some feeds provide more than one nutrient; select the category with the highest nutrient proportion in the feed.

Table 1. Nutrient Categories
Carbohydrate	Protein	Fat	Vitamin	Mineral

Part Two – Feed Classifications

Using the feed samples, in Table 2 classify each feedstuff into one of the three common livestock feedstuff categories. Hint: Use the definitions of the categories as a guide.

Table 2. Feed Classifications
Roughage	Concentrate	Supplement

Part Three – Feedstuff Variability

Use nutritional tables to locate differences in the nutrient content of a feed. Go to United States-Canadian tables of feed composition: Nutritional data for United States and Canadian feeds, third revision at URL: http://books.nap.edu/openbook.php?record_id=1713&page=7.

Find alfalfa in the feed composition table. Answer the following questions based on your observations of the feed composition tables and your notes from the Feedstuffs presentation.

1. How is the data divided into regions?

2. What affect might regional differences have on hay quality?

3. How is the data divided into time of harvest?

4. Why might time of harvest affect nutrient value?  

Conclusion

1.  Why do rations typically contain more than one feedstuff?

2. List three feedstuffs readily available in your area.

3. What is the primary difference between a concentrate and a roughage?