Introduction to animal nutrition
There are seven major classes of nutrients: carbohydrates, fats, fiber, minerals, protein, vitamin, and water. These nutrient classes can be categorized as either macronutrients (needed in relatively large amounts) or micronutrients (needed in smaller quantities). The macronutrients are carbohydrates, fats, fiber, proteins, and water. The micronutrients are minerals and vitamins. The macronutrients (excluding fiber and water) provide structural material (amino acids from which proteins are built, and lipids from which cell membranes and some signaling molecules are built) and energy. Some of the structural material can be used to generate energy internally, and in either case it is measured in joules or calories (sometimes called "kilocalories" and on other rare occasions written with a capital C to distinguish them from little 'c' calories). Carbohydrates and proteins provide 17 kJ approximately (4 kcal) of energy per gram, while fats provide 37 kJ (9 kcal) per gram., though the net energy from either depends on such factors as absorption and digestive effort, which vary substantially from instance to instance. Vitamins, minerals, fiber, and water do not provide energy, but are required for other reasons. A third class dietary material, fiber (i.e., non-digestible material such as cellulose), seems also to be required, for both mechanical and biochemical reasons, though the exact reasons remain unclear. Molecules of carbohydrates and fats consist of carbon, hydrogen, and oxygen atoms. Carbohydrates range from simple monosaccharides (glucose, fructose, galactose) to complex polysaccharides (starch). Fats are triglycerides, made of assorted fatty acid monomers bound to glycerolbackbone. Some fatty acids, but not all, are essential in the diet: they cannot be synthesized in the body. Protein molecules contain nitrogen atoms in addition to carbon, oxygen, and hydrogen. The fundamental components of protein are nitrogen-containing amino acids, some of which areessential in the sense that humans cannot make them internally. Some of the amino acids are convertible (with the expenditure of energy) to glucose and can be used for energy production just as ordinary glucose. By breaking down existing protein, some glucose can be produced internally; the remaining amino acids are discarded, primarily as urea in urine. This occurs normally only during prolonged starvation. Family| Sources| Possible Benefits|
flavonoids| berries, herbs, vegetables, wine, grapes, tea| general antioxidant, oxidation of LDLs, prevention of arteriosclerosis and heart disease| isoflavones (phytoestrogens)| soy, red clover, kudzu root| general antioxidant, prevention of arteriosclerosis and heart disease, easing symptoms of menopause, cancer prevention| isothiocyanates| cruciferous vegetables| cancer prevention| monoterpenes| citrus peels, essential oils, herbs, spices, green plants, atmosphere| cancer prevention, treating gallstones| organosulfur compounds| chives, garlic, onions| cancer prevention, lowered LDLs, assistance to the immune system| saponins| beans, cereals, herbs| Hypercholesterolemia, Hyperglycemia, Antioxidant, cancer prevention,Anti-inflammatory| capsaicinoids| all capiscum (chile) peppers| topical pain relief, cancer prevention, cancer cell apoptosis| -------------------------------------------------
Carbohydrates may be classified as monosaccharides, disaccharides, or polysaccharides depending on the number of monomer (sugar) units they contain. They constitute a large part of foods such as rice, noodles, bread, and other grain-based products. Monosaccharides contain one sugar unit, disaccharides two, and polysaccharides three or more. Polysaccharides are often referred to as complex carbohydrates because they are typically long multiple branched chains of sugar units. The...