| A | B |
| Water | most important constituent in plant and animal tissues |
| Carbohydrates | C-H-O (formed by photosynthesis) |
| Cellulose | polysaccharide only digested by microbes in the rumen |
| Monosaccharides | simple sugars |
| Lipids | 2.25 times a much energy as C-H-O |
| Saturated Fats | Solid at room temperature |
| Unsaturated Fats | Solid at room temperature |
| Protein | C-H-O-N (with lesser amounts of sulfur and phosphorus) |
| Inidvidual units of protein | Amino Acids |
| Nonessential Amino Acids | synthesized in the animal's body |
| Essential Amino Acids | NOT synthesized in the animal's body |
| Pvt. Tim Hall | Essential Amino Acids |
| Minerals | (inorganic) dietary essentials for specific metabolic functions |
| Vitamins | organic substances required in very small amounts |
| mastication | chewing |
| Deglutition | swalling |
| Regurgitation | movement of digesta in reverse order from the stomach to the mouth |
| Defecation | voiding the fecal materials from the body |
| Herbivores | consume plant materials |
| Omnivores | consume plants and flesh |