Rations, Feed Additives and Hormone Implants 6.01-6.02 Rations, Feed Additives and Hormone Implants

Six Functions of Good Ration Maintenance- basic nutrient requirements to keep vital body processes functioning. All animals need maintenance requirements met, before other functions will work. Growth- increasing the size of bones, muscles, organs and connective tissue. Fattening- storing nutrients not used for maintenance, growth or other functions. Production- milk, eggs, wool, etc. Reproduction- gestation, parturition and lactation. Work- other needs are met before nutrients are available for work. Most beef cattle, swine and poultry produced in the U.S. do not 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.

Roughages Feeds that contain more than 18% crude fiber when they are dry. Examples of Roughages Hay. Pasture grasses. Silage. Hulls. Straw. Fodder.

Concentrates Feeds that contain less than 18% crude fiber when they are dry. Examples of Concentrates Grains- corn, oats, barley, wheat, etc. Processed by-products- wheat bran, middlings, etc. Liquid supplements- molasses, urea. Animal proteins- meat scraps, tankage, fish and blood meal. Plant proteins- cottonseed meal, soybean meal, peanut meal and linseed meal.

General Principles of a Good Ration  Balanced- has all nutrients needed in the right amounts and proportions at the least expense. Palatable- tastes good so that animals will eat it. Include a variety of feeds to improve palatability and make it easier to balance. Succulent to make it fresh and appealing. Bulky to satisfy hunger and help digestive system function properly. Slightly laxative to improve feed efficiency and prevent constipation.

General Principles of a Good Ration Low Cost- best nutritional value possible at lowest cost because feed costs are about 75% of the total costs of raising livestock. Price per pound of energy and digestible protein determine if the ration is economical. Not harmful to health or quality of animal products. Proper proportions of concentrates and roughages for type and age of animal. Examples: more roughages for cattle, more concentrate for swine and poultry, higher protein for younger animals, etc. Uniformly mixed especially micronutrients and feed additives.

Rules of Thumb for Feeding Livestock  Beef Cattle- fattening ration should include 1 ½– 2 pounds of air-dried roughage and 2 pounds of concentrate per 100 pounds of body weight. Cows nursing calves should be fed about 50% more than dry cows. Swine- the amount fed depends on size and age of animal and whether sows are nursing. Pigs under 50 pounds and sows that are nursing require higher percent protein feeds than market hogs. Poultry- the ration is about 10% of body weight.

Feeding Livestock on 100% Dry Matter versus As-Fed Basis Relationship- the weight of 100% dry matter basis is less than as-fed basis because 100% dry has no water. Feed reference tables show % dry matter in most kinds of feed. 100% dry matter basis of sun-cured hay is about 90% of as- fed basis. 100% dry matter basis of most fresh pasture grasses is about 20-30% of as-fed basis. 100% dry matter basis of most corn (NOT silage) is about 90% of as-fed basis. Storing high moisture feed materials will cause them to mold or to build up heat.

Steps in Balancing a Ration Step 1- Identify the kind, age, weight and function of the animal(s) you will be creating a ration for. Step 2- Consult nutrient requirement reference tables known as feeding standards. Step 3- Choose feeds to create the ration. Common nutrient contents or various feeds are found in reference tables. Select feeds that are economical but meet requirements. Step 4- Calculate the amounts of each feed to use. Computer programs can calculate rations or methods such as Pearson Square can be used. Step 5- Verify the ration meets the nutrient needs of the animal, especially vitamins and minerals.

Feed Additives and Hormone Implants 6.02

Feed Additives Feed Additives-materials used in animal rations in small quantities to improve or stimulate performance such as feed efficiency, faster gain and health or production of animal products including eggs, milk, wool, etc. Feed additives are not generally considered nutrients. They are performance stimulants and increase profits because of improved performance. Feed additives are widely used in beef cattle, swine, and poultry.

Feed Additives The use of feed additives and hormone implants are regulated by the Food and Drug Administration (FDA). Any feed with any drug in it must be labeled as medicated feed. Many feed additives have withdrawal times where animals must be taken off additive for a specified period of time before the animal is slaughtered. Many antibiotic and antibacterial type additives are administered at subtherapeutic levels. Subtherapeutic- medication fed at lower levels to prevent rather than treat disease. A major health concern of this low-level use is that microorganisms that cause diseases may become resistant to the drugs used for treatment. Many different antimicrobial drugs are used as feed additives to prevent diseases and to increase performance in livestock and poultry. The greatest return for swine is in young pigs.

Mixing Feed with Additives The main rule that includes all other rules is “read and follow the label.” Uniform mixing of additives in livestock feed is required so that all animals get the correct amounts of the additive. To avoid medicated drug contamination of feed, the feed mixer must be thoroughly cleaned. It is important that accurate up-to-date records be kept on the use of medicated feed.

Kinds of Feed Additives Antimicrobial Drugs- antibiotics and antibacterials used to prevent and control diseases. Hormones- feed additives used to improve feed efficiency and rate of growth. Mainly used for beef cattle. Anthelmintics- used to control worms. Other Feed Additives Coccidiostats- controls coccidiosis in poultry and cattle. Poloxalene- prevents bloat in beef cattle.

Feed Additive Examples Broad-spectrum antibiotics when the specific disease is unknown. Melengestrol of MGA to suppress estrus or heat in heifers. Aureomycin, Terramycin, and penicillin are antibiotics for swine. Piperizine and Dichlorvos are worm control additives.  

Hormone Implants Pelleted synthetic or natural hormones or hormone like compounds placed under the skin or in the muscle of an animal to improve rate of gain and feed efficiency.

Hormone Implant Procedure Restrain the animal to prevent head movement. Use a sharp needle to eliminate crushed pellets usually caused by dull needles. Be sure the needle and the implantation site are clean. Select the proper place for the implant on the back surface of the ear in the middle one third of the ear which is 1 1/2” to 2” from the base of the ear. Point the implanting instrument toward the head and parallel to the ear, lift the loose skin with the point of the needle and push the needle in being careful NOT to hit a vein or the cartilage. Withdraw the needle slightly, start the implant, make certain the pellets have been properly deposited and slowly withdraw the needle. If the needle is removed too fast, the hormone pellets may be crushed or balled up. Crushing pellets causes them to be absorbed too rapidly. Be careful to avoid implanting in cartilage because the pellet may become encapsulated causing slower absorption. Be careful to avoid veins because the hormone pellet may be lost because of excessive bleeding.