1. Unit F: Principles of Animal Nutrition
Animal Science II
Unit F: Principles of Animal Nutrition

2. Objective:
Obj. #13: Analyze the role of rations in animal health and productivity.

3. Six Functions of Good Ration
1. Maintenance of vital body processes to keep animal alive
2. Growth by increasing the size of bones, muscles, organs and connective tissue.
3. Fattening by storing nutrients not used for maintenance, growth or other functions.
4. Production of milk, eggs, wool, etc.

4. 5. Reproduction – adequate nutrition is necessary
6. Work – other needs are met before nutrients are available for work. Most beef cattle, swine and poultry produced in the U.S. do no work.
*From 1/3 to 1/2 of the ration fed to beef cattle and swine is used for body maintenance, and this function must be met before nutrients are available for other functions.

5. 13.02

6. A. Roughages
1. Roughages are feeds that contain more than 18% crude fiber when they are dry.
2. Examples of roughages
a. hay
b. pasture grasses
c. silage
d. hulls
e. straw
f. fodder

7. B. Concentrates
1. Concentrates are feeds that contain less than 18% crude fiber when they are dry.
2. Examples of concentrates
a. grains – corn, oats, barley, wheat, etc.
b. processed by-products – wheat bran, middlings, etc.

8. c. liquid supplements – molasses, urea
d. animal proteins – meat scraps, tankage, fish and blood meal
e. plant proteins – cottonseed meal, soybean meal, peanut meal and linseed meal

9. 13.03

10. Characteristics of a Good Ration
1. Balanced – has all nutrients needed in the right amounts and proportions.
2. Palatable – tastes good so that animals will eat it.
3. Low cost – best nutritional value possible at lowest cost because feed costs are about 75% of the total costs of raising livestock.

11. 4. Not harmful to health or quality of animal products
5. Proper proportions of concentrates and roughages for type and age of animal.
6. Uniformly mixed especially micronutrients and feed additives