Common Terms Used in Animal Feeding and Nutrition
Fat: Chemically, fats are “triglycerides of fatty acids” that are a high density source of energy for animals. Fat is rich in energy; it contains 2.25 to 2.8 times the energy found in carbohydrates and it is highly digestible. Fat is added to rations to boost energy levels when intake may be limiting due to a reason like poor animal health, less palatable feed, or environmental stress. Some concentrates (such as soybean meal) contain relatively high levels of fats and oils. Fats are composed of building blocks called fatty acids. Fats in feed samples are typically determined through ether extraction (EE). In addition to fat, EE may solubilize some other compounds like plant pigments, esters and aldehydes. This is why the measurement of fat through EE is called crude fat. True fat can be measured by determining the content of fatty acids or it can be estimated in forages as ether extract minus one.
Forage: Edible parts of plants, other than separated grain, that can provide feed for grazing animals, or that can be harvested for feeding. Forage may be fresh, dry, or ensiled (e.g., pasture, green chop, hay, haylage).
Forage Quality: Forage quality refers to the ability of a forage to support desired levels of animal performance (e.g., daily gain or milk production). It is a function of voluntary intake and nutritive value (nutrient content and digestibility)