FEED NUTRIENTS Agriscience 332 Animal Science #8647-A TEKS: (c)(3)(B)

Introduction Feeding livestock requires the producer to supply adequate amounts of nutrients to the animals based on their nutritional needs, not just giving animals any available feed.

Livestock and poultry require adequate amounts of nutrients from six classes for growth, maintenance, finishing, work, reproduction, and lactation.

The producer must consider the animal’s nutritional needs based on the species and function of the animal when selecting feeds. The producer must also consider availability and cost of feeds.

Any food that sustains life contains nutrients which the animal converts into useful forms via the digestive system. Blood absorbs nutrients from the digestive system and carries them throughout the body.

Nutrients pass through capillary walls and enter body cells to provide nourishment and energy for life processes.

Nutrients can either be essential or non-essential, depending on the class of the animal. An essential nutrient is one that the body cannot produce and must be supplied by the feed. A non-essential nutrient is one that can be synthesized in the body.

Classes of Nutrients There are six classes of nutrients that must be supplied by daily feed rations. Protein Carbohydrates Fats and Oils Minerals Vitamins Water

Protein Proteins are complex organic macromolecules that always contain carbon, hydrogen, oxygen, and nitrogen; some also contain sulfur or phosphorus.

Proteins consist of one or more chains of amino acids and are the fundamental components of all body cells.

Proteins make up enzymes, hormones, antibodies, and other substances necessary for proper body function. Proteins are essential for growth and repair of tissues.

Proteins can be obtained from feeds containing meat, fish, egg, milk, and legume products.

During digestion, proteins are broken down into amino acids, which are carried by the blood to the body’s cells.

Non-ruminant (single stomach) animals can manufacture 12 of the 22 amino acids required. They cannot store the amino acids in their bodies, so they must get the other 10 amino acids daily in protein feeds.

Ruminants can manufacture all amino acids required by their bodies, as long as they have a nitrogen source from which the microbes in the rumen can construct essential amino acids.

Sources of Protein: There are two sources of proteins, plant protein and animal protein.

Plant proteins come directly or indirectly from plants. Sources of plant proteins include soybean meal, cottonseed meal, linseed meal, and alfalfa meal.

Animal proteins are usually by-products of fish, dairy, and meat processing plants. Sources of animal protein include tankage, meat scraps, fish meal, and dried milk.

Because of BSE (Mad Cow’s Disease), in 1997 the FDA prohibited the use of mammalian protein in the manufacturing of feeds for ruminants.

Classes of Proteins: Proteins are classified based on digestibility as either crude protein or digestible protein.

Crude protein is the total amount of protein contained in a feedstuff, including digestible and non-digestible.

Digestible protein is the percentage of the crude protein that can be easily digested by the animal. An animal digests approximately 80% of the crude protein in feedstuff.

Carbohydrates Carbohydrates are organic compounds that contain only carbon, hydrogen, and oxygen, usually in a 1:2:1 ratio. Carbohydrates are produced by photosynthetic plants; they include sugars, starches, celluloses, and gums.

Carbohydrates, which can be found in feed grains, serve as a major energy source for animals. Carbohydrates make up almost 75% of an animal’s ration; excess carbohydrates produce fat in an animal.

Types of Carbohydrates: There are two types of carbohydrates based on digestibility, nitrogen-free extract and crude fiber.

Nitrogen-free extract consists of sugars and starches, such as those found in grains. It is highly digestible and considered the more soluble form of carbohydrate.

Crude fiber comes from highly fibrous plants and cannot be easily digested by animals.

Fats and Oils Like carbohydrates, fats and oils provide energy for animals. Fats and oils are the densest forms of energy, providing 2.25 times more energy than carbohydrates, and are derived from plants and animals.

At room temperature, fats are solids and oils are liquids. Animals require only small amounts of fats and oils, but they are very important nutrients in the ration.

Minerals Minerals are inorganic elements that are necessary for the maintenance of life and good health. Some minerals are essential components of body tissues, while others help regulate metabolic activities.

Minerals are divided into two groups, based on their availability and animals’ needs. Macro minerals Trace minerals (micro)

Macro minerals are required in larger quantities than trace minerals and must be supplied in the feed ration. An overabundance of any macro mineral is harmful to the animal.

Macro Minerals: Calcium (Ca) Phosphorus (P) Sodium (Na) Chlorine (Cl) Potassium (K) Magnesium (Mg)

Calcium and phosphorus are the most abundant of the minerals in a feed ration. All biochemical reactions require calcium and phosphorus. The calcium to phosphorus ratio (1.5 to 1) is important in feed rations.

Calcium is necessary for heartbeat regulation, blood clotting, muscle contractions, and bone and teeth maintenance.

Phosphorus is an essential constituent of protoplasm, bones, and teeth.

Sodium and chlorine are usually found together as sodium chloride (NaCl or common salt). Salt helps maintain acidity levels in body fluids and proper pressure in body cells.

Hydrochloric acid, which is produced by the stomach, contains chlorine.

Potassium helps maintain proper acid levels in body fluids and pressure in body cells. Potassium is also required in some enzymatic reactions in carbohydrate metabolism and protein synthesis.

Magnesium is necessary for utilizing energy in the body and for bone growth.

Trace minerals or micro-minerals are needed by animals in very small amounts, but are essential for performing many body functions.

Trace minerals: Copper (Cu) Fluorine (F) Manganese (Mn) Selenium (Se) Molybdenum (Mo) Zinc (Zn) Iodine (I) Cobalt (Co) Iron (Fe)

Trace minerals are involved in performing the following body functions: Growth of bones, soft tissues, and teeth; Blood and body fluid processes; Vitamin utilization;

Regulation of chemical processes; Reproduction; Digestion; Body tissue repair; Release of body heat for energy needs;

Muscle activity; and Internal organ functioning.

Vitamins Vitamins are organic compounds needed in small amounts by the body for growth, maintenance, reproduction, and lactation. Unlike minerals, vitamins do not build body tissues.

Vitamins are obtained naturally from plant and animal feedstuff.

There are two types of vitamins based on solubility and storage in the body: Fat-soluble vitamins, and Water-soluble vitamins.

Fat-soluble vitamins can be stored in the body. Large amounts of fat-soluble vitamins can be deadly to an animal.

Fat-soluble Vitamins: Vitamin A Vitamin D Vitamin E Vitamin K

Water-soluble vitamins cannot be stored in the body. It is important that there is a regular intake of adequate amounts of water-soluble vitamins.

Water-soluble Vitamins: Thiamin (Vitamin B1) Riboflavin (Vitamin B2) Pyridoxine (Vitamin B6) Vitamin B12 Folic Acid Biotin (Vitamin H)

Choline Inositol Niacin (Nicotinic Acid) Pantothenic Acid Vitamin C

Water All animals require water for body functions. Water is the largest component of bodies, constituting approximately 50% of body mass.

Water is necessary for the following body functions: digestion and absorption of nutrients; removal of waste; production of milk; shaping of cells; and regulating body temperature.

The animal’s feeding habits directly affect the amount of water consumed. Animals require approximately three pounds (about 1/3 gallon) of clean water for each pound of solid feed eaten.

Summary Animals need adequate nutrition for their bodies to function properly. A producer must know what nutrients are required in an animal’s diet, based on the purpose of the animal, and provide the animal with the correct nutrition.

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