Swine Fact Sheet Animal Sciences Auburn University

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1 Swine Fact Sheet Animal Sciences Auburn University SFS-0112 May, 2012 Swine Dietetics: Basic Swine Nutrition W.F. "Frank" Owsley Extension Animal Scientist / Associate Professor Auburn University Feed accounts for a large part of the production costs for a swine operation. Small changes in a feed program can have a great effect on profit or loss. Developing a sound feeding program should be a high priority for anyone wanting to make money with hogs, from the smallest low investment unit to the largest confinement unit. A good feeding program is one that provides the right nutrients in the right amounts, from the best ingredients and at the lowest price. This requires some knowledge of swine nutrition. Before setting up a feeding program, producers should be aware of the nutrients required by swine, the ingredients needed to supply these nutrients and how these ingredients should be processed and mixed. Nutrients The term nutrient is used to describe the chemical compounds an animal must consume for maintenance and growth. Nutrients fit into five major groups: protein, energy, minerals, vitamins and water. A properly formulated swine diet will contain the amount of each nutrient needed for growth, milk production, pregnancy or maintenance. This amount is the nutrient requirement. Tables 1 and 2 contain the minimum recommended nutrient allowances for all classes of swine. Each nutrient plays an important role in economical production of pork. Protein For many years, swine diets were formulated based on protein. During the past 20 years, we have learned that this method of formulation is not always accurate. Protein is made up of chains of amino acids, commonly called the building blocks of protein. We know now that pigs require certain amounts of amino acids which are not always supplied when a diet is formulated based on protein. It is important for a pig farmer to be aware of the importance of amino acids when feeding swine. When protein is digested, it is broken down into individual amino acids. These are absorbed through the gut of the pig, then used to form other proteins (primarily muscle). Of the 22 amino acids found in muscle protein, only 10 must be supplied in the diet: lysine, tryptophan, threonine, methionine+cystine, leucine, isoleucine, arginine, valine, histidine and ALABAMA A&M AND AUBURN UNIVERSITIES, AND TUSKEGEE UNIVERSITY, COUNTY GOVERNING BODIES AND USDA COOPERATING The Alabama Cooperative Extension System offers educational programs, materials, and equal opportunity employment to all people without regard to race, color, national origin, religion, sex, age, veteran status, or disability.

2 phenylalanine+tyrosine. These are commonly called the indispensable amino acids. The pig is able to make (synthesize) the others. The pig can synthesize protein as long as the needed amino acids are present. If one amino acid is short (limiting), protein synthesis stops. In common swine diets, lysine, tryptophan and methionine + cystine may be limiting. A properly formulated diet will contain enough protein to meet the requirement of the limiting amino acid(s). If this requirement is met, all other amino acids will be adequate. Energy The energy in a swine diet is a major factor in all body functions. Metabolizable energy (ME) is the portion of the total energy content (gross energy) that is available for these functions. Carbohydrates (starch), fat and protein are all used to meet the pig's ME requirement. The ME content of a swine diet plays a major role in feed intake. Pigs tend to eat enough feed to meet their energy requirement. If there is not enough energy in the form of carbohydrates or fat in the feed, dietary and sometimes body protein is broken down and used for energy. This becomes critical during periods of reduced feed intake (heat stress, weaning) and high energy demand (lactation). High energy ingredients (fat) must be added during these periods to increase the daily energy intake. Minerals Minerals of importance in swine diets are classified as macro- or micro-minerals. Calcium, phosphorus and salt (sodium and chlorine) are considered macro-minerals because of the fairly high levels required by swine. Iron, zinc, copper, manganese, iodine and selenium are micro-minerals. Other minerals are required, but are normally found in high enough levels in typical feed ingredients. Calcium and phosphorus. Roughly 99 percent of the calcium and 80 percent of the phosphorus in the body are found in bones and teeth. Calcium is also required for blood clotting and for muscle function. Phosphorus plays an important role in energy use by cells. Feeding swine diets low in calcium and phosphorus will result in poor growth and weakened bones. Excess calcium is common and can produce symptons of phosphorus and zinc deficiency. It is important to meet the requirement of both calcium and phosphorus. It is also important to maintain a calcium-phosphorus ratio of 1:1 to 1.5:1. Salt. Sodium and chlorine are the two elements that make up salt. The minimum salt requirement for growing pigs is 0.25 percent. Most recommendations are in the range of 0.25 to 0.50, depending on the weight/class of the pig and the salt content of water. Sodium is required for normal nerve function. Chlorine forms part of hydrochloric acid, required for digestion in the stomach. Feeding salt deficient diets results in poor performance and loss of apetite. Pigs can stand high levels of salt if adequate water is available. If adequate water is not present, high levels of salt can result in death. Iron. Iron is needed for supplying oxygen to cells. It allows oxygen to be carried in the blood. It is also a part of several enzyme systems. Iron deficiency results in weak, poor growing pigs. High levels of iron in the diet can damage nerves and intestinal lining. Deficiency symptoms of other minerals are also seen. Zinc. Zinc plays a role in the function of several enzymes. Zinc deficiency results in reduced feed intake, poor growth, parakeratosis (a skin disorder) and affects sexual development

3 in boars. High levels of calcium in the diet can produce zinc deficiency. High levels of zinc may produce deficiencies of iron, phosphorus and other minerals. Copper. The pigs requirement for copper is low compared to most other minerals. Copper increases the pigs ability to use iron, and like other trace minerals, is important in several enzyme systems. Feeding inadequate copper produces symptons similar to iron, zinc and phosphorus deficiency. High levels (125 to 250 ppm) have been shown to improve performance in young pigs. This is thought to be an antibiotic effect in the gut of the pig. The benefit of feeding these levels decreases as the age of the pig increases. Manganese. Manganese is important for normal bone development, reproduction and energy use. Feeding high levels of manganese reduces feed intake and gains. Iodine. Iodine forms part of thyroid hormones, which control the rate of many body functions. The requirement is even lower than copper, but sows eating iodine deficient diets produce weak, hairless and dead pigs. High levels of iodine reduce the pig's ability to use iron. Selenium. The amount of selenium that can be added to swine diets is limited by the Food and Drug Administration. Up to 0.3 ppm can be added to swine diets. Selenium is required for maintaining cell membranes. Deficiency of this mineral results in poor reproduction, white muscle disease and possibly death. As little as 5 ppm selenium can be toxic, affecting gain and reproduction. Vitamins The role of vitamins in the body differs from that of most other nutrients. Vitamins are not part of the structure of bone, muscle or other body tissue. Their main purpose is to control chemical reactions required for normal body functions. Some vitamins can be stored in the body. These are called fat-soluble vitamins. They are absorbed from the gut and also stored along with fat. Water-soluble vitamins are constantly removed from the body with the large volume of water passing through the pig. Fat-soluble vitamins required in swine diets are vitamins A, D, E and K. Water-soluble vitamins required in swine diets include riboflavin, niacin, pantothenic acid, choline and vitamin B 12. There is evidence that adding biotin and folic acid to sow diets may also be necessary. Other vitamins are required, but the levels in common feedstuffs are adequate. Vitamin A. Plant products used in swine diets contain no vitamin A. Some do contain carotene, which is converted to vitamin A in the intestinal wall of the pig. The levels of carotene vary greatly between different ingredients and between batches of the same ingredient. Carotene is easily destroyed in storage, so vitamin A must be added to swine diets. Feeding diets low in vitamin A can cause nerve damage, reduced growth and appetite, night blindness, total blindness and reproductive problems. Vitamin D. The main role of vitamin D is controlling the levels of calcium and phosphorus in blood and bones. Some vitamin D is produced by pigs with access to sunlight, but additional vitamin D in the feed is required. Young animals fed diets low in vitamin D can develop a disease known as rickets. Calcium and phosphorus are not deposited in bones, making them soft bones. In adults, a disease known as osteomalacia develops. Calcium and phosphorus are removed from bones, leaving them brittle. Vitamin E. Vitamin E and selenium are closely related. Decreasing the level of one increases the requirement of the other. Vitamin E is an antioxidant: it prevents rancidity in feed. This increases the level of vitamin E required in swine diets. The symptoms of vitamin E

4 deficiency are similar to those of selenium deficiency. Vitamin K. Vitamin K is required for normal blood clotting. Unusual bleeding, increased clotting time and death may result from feeding diets low in vitamin K. The requirement for vitamin K is low, but the level in common feed ingredients is also low. Vitamin K, in the form of menadione, should be added to swine diets. Water-soluble vitamins. Water-soluble vitamins included in swine diets either control or are a part of many chemical reactions in the body. For years, many of these vitamins were known only as "unidentified growth factors". Alfalfa and some animal products were added to swine diets because they contained these growth factors. Most are how known as water soluble vitamins and are included as vitamin premixes, basemixes and supplements. Feeding swine diets low in one or more water-soluble vitamins will result in reduced growth and appetite. Other symptoms are: Water riboflavin: poor conception and reproduction niacin: diarrhea, hairless and skin problems (dermatitis) pantothenic acid: "goosestepping", diarrhea, low fertility choline: abnormal gait, reproductive failure B12: uncoordinated hind-leg movement, reproductive failure biotin: cracking of the feed, dermatitis Water is the most important nutrient and often the most ignored. Water makes up 40 to 80 percent of a pig, depending on age. It serves as the carrier for nutrients, in waste removal and temperature regulation. It is essential for sight, hearing, digestion, breathing and maintaining the nervous system. A pig can survive longer without feed than without water. Fortunately, water is cheap and available. A pig farmer should provide an adequate, clean supply of water before anything else. Pigs from 30 pounds to market will drink 0.3 to 2 gallons of water daily, gestating sows 4 to 5 gallons and lactating sows 5 to 6.5 gallons. If a pig does not receive adequate water, a condition known as salt toxicity can occur. This affects the nervous system and can result in death. Ingredients Determining the nutrients required in swine diets is the first step in developing a sound feeding program. The next step is deciding what ingredients to combine to meet the nutrient requirements. Table 3 contains the nutrient content of feed ingredients commonly used in swine diets. These ingredients include grains, high protein feedstuffs, mineral sources and several miscellaneous ingredients. Grains Grains provide most of the energy in a swine diet. Traditionally, the value of a grain is based on its energy content. Corn is the standard grain. The recommendations in tables 1 and 2 are based on diets containing corn. Corn is an excellent source of energy. It also supplies up to 50 percent of the protein and 30 percent of the lysine in swine diets. Corn contains low levels of

5 calcium and trace minerals, but can provide 40 percent of the total phosphorus in swine diets. This can be misleading. Two thirds or more of the phosphorus from plant sources is bound with phytic acid. As little as 20 percent of this phosphorus is available for use by the pig. Other grains are available for use in swine diets. Some are equal to or better than corn, while others have a lower value. Wheat, grain sorghum and some varieties of triticale can replace corn with little or no effect on swine performance. Wheat is equal to corn in energy and contains more protein and lysine than corn. Bird resistant grain sorghum contains 85 to 95 percent energy in corn. Nonbird resistant varieties contain 95 to 100 percent the energy in corn. Both contain higher levels of protein, but slightly lower levels of lysine. Triticale contains 98 to 100 percent the energy in corn, and has almost twice the level of lysine found in corn. Properly formulated swine diets with wheat or triticale as the only grain will be similar to corn based diets in energy content, but will contain less of the protein source used (usually soybean meal). Corn can be replaced with grain sorghum pound for pound, but the diet will have slightly less energy and lysine. Barley, oats and rye can also be included in swine diets, but the energy content of the diet will be lower. Barley contains 85 percent of the energy in corn, oats.80 percent and rye 82 percent. All contain higher levels of protein and lysine. The lower energy content in each limits their use in swine feeds. Oats and barley can be used as the only grain if a high energy ingredient such as fat is added. Rye can make up only 20 percent of swine diets. Adding higher levels of rye may reduce feed intake and gains. During periods of cold weather, finishing hogs may benefit from barley in the diet. Adding a moderately high fiber ingredient such as barley (7 percent fiber) may increase the heat produced by these pigs which reduces the heat required during cold weather. Grain by-products from the milling industry, bakeries and alcohol can also be used in swine feeds. These products generally contain higher levels of protein and lysine, but contain only 60 to 80 percent of the energy found in the whole grains. The economics of using these ingredients must be evaluated before they are included in swine diets. High Protein Feedstuffs While corn is the standard source of energy for swine, soybean meal is the typical protein source for swine diets. The amino acid content of soybean meal compliments that of corn. Corn is low in lysine and tryptophan: soybean meal contains high levels of each. The availability of the amino acids in soybean meal is high (pigs can use a high percentage of each amino acid). When the price of soybean meal is high, alternative sources of protein are sought. Other plant products can be used a protein sources for swine diets. Cottonseed meal is a popular protein source for cattle, but its use in swine diets is limited. Cottonseed meal contains less protein and lysine than soybean meal. It also contains a compound called gossypol, which is toxic to swine. Gossypol binds both lysine and iron, making them unavailable to swine. Cottonseed meal should replace no more than half the lysine from soybean meal in swine diets. Peanut meal contains more protein than soybean meal, but less lysine. Its use in swine diets should also be limited. Soybeans can provide an excellent source of both energy and lysine, but contain several compounds that reduce pig performance. Heat treatment destroys these compounds. Cooked soybeans contain more energy than soybean meal because of their higher fat content. Properly heated soybeans can be an excellent alternative to soybean meal if the price is

6 right. There are many other plant products that contain high levels of protein and can be used in pig diets. Some are by-products of grain processing (distillers grains, corn gluten, brewers grains). These are typically lower in energy than corn because the starch has been removed. They are higher in protein, fat and fiber. Other oilseeds (sunflowers, canola, flax seed, etc.) can be part of practical diets if they are available at a price farmers can afford. Animal protein products were once the primary protein source for swine. This was due as much to their high levels of other nutrients (minerals, vitamins) as it was to their high protein content. Meat and bone meal is still used in many swine diets because of its high phosphorus content. Unlike phosphorus from plant sources, the phosphorus in meat and bone meal is readily used by swine. The main problem with animal by-products is product variation. The level and availability of amino acids can vary greatly between batches from the same processor. This can lead to trouble for the producer or small feedmill using small amounts of animal by-products. Blood meal and possibly tankage may reduce intake in pigs if high levels are used. Addition of some blood meal may improve the balance of amino acids in swine diets, but little improvement in pig performance has been shown. Some animal protein products are often used in diets for weaned pigs. Menhaden fish meal is an excellent source of protein and amino acids for pigs. Young pigs may prefer diets containing some fish meal. The high cost limits its use in most other swine diets. Dried skim milk is also an excellent source of amino acids for young pigs. Most milk replacers and diets for early weaned pigs contain high levels of dried skim milk. It provides both energy and amino acids that are easily digested by the young pig. The cost also limits its use in other swine diets. Mineral Products Most ingredients commonly used in swine diets are plant products and poor sources of minerals. As mentioned earlier, some animal products are excellent sources of minerals. To meet the mineral requirements of swine, it is often best to find a mineral package developed specifically for the animal you are feeding. These products, usually called basemixes, contain calcium, phosphorus, salt, trace minerals and vitamins. Most are added at the rate of 50 to 100 pounds per ton of complete feed. Miscellaneous Ingredients Several common feed ingredients do not fit any of the above groups, but are still important. Whey is a by-product from milk used in diets for young pigs. Dried whole whey contains over 60 percent lactose (milk sugar). Lactose is an excellent source of energy for pigs after weaning. Fat is often used to increase the energy content of swine feed. Animal fat is available to many Southeastern pig farmers. It contains over twice as much energy as corn and is commonly used in diets for lactating sows and growing/finishing pigs. Research has shown an improvement in pig and sow performance when 3 to 5 percent fat is included in the diet. Processing and Mixing Using the right ingredients to meet the nutrient requirements of swine is important. Unless these ingredients are processed and mixed properly, pig performance and profits may

7 suffer. Processing Grains should be processed to improve nutrient use and/or mixing. Grinding is the preferred processing method for most grains. The exception is wheat and possibly triticale. Research has shown an improvement in growing/finishing pig performance when wheat is coarse rolled rather than ground. Fine grinding of all grains improves nutrient availability, but can result in ulcers. A medium grind is recommended for corn and grain sorghum. If a roller mill is not available, a coarse grind is recommended for wheat and triticale. Mixing Any feed mixing system is as good as the effort going in. Use the following steps as a guide for setting up or evaluating a mixing system. Even a slight improvement in feed quality could mean savings in feed costs. 1. Follow instructions on feed tags or formulations exactly. 2. Have ingredients analyzed regularly. 3. Have formulations adjusted by a competent nutritionist as the nutrient content of ingredients or the ingredients themselves change. 4. Compare ingredient costs and feeding value before buying a "cheap" ingredient. 5. Keep all feed handling equipment (mixers, augers, bins, feeders) in good repair. 6. Weigh all ingredients before mixing. 7. Avoid under-mixing and over-mixing. 8. Have feeds analyzed regularly. Conclusion Feeding swine can be a complicated process. It requires putting a group of ingredients together that will provide the nutrients required for growth, maintenance or reproduction. Purchasing a complete feed is often the most expensive option on a cost per unit of feed, but it will come with a guarantee. Mixing local ingredients yourself can reduce the cost per pound of feed, but there is no guarantee. If you have an idea what you want to raise and the resources available to you, a feeding program can be developed to reach your goal. Table 1. Nutrient allowances of starting, growing and finishing swine (Percentage or amount per pound of diet) Liveweight class, lb. Nutrient < mkt. Metabolizable energy, kcal/lb 1,400 1,400 1,400 1,400 1,400

8 Protein, % Lysine, % Calcium, % Phosphorus, % Salt, % Iron, mg Copper, mg Zinc, mg Selenium, mg Vitamin A, IU 3,000 3,000 2,500 1,500 1,500 Vitamin D, IU Vitamin E, IU Vitamin K, mg Riboflavin, mg Niacin, mg Pantothenic acid, mg Vitamin B12, mcg This is only a partial list of required nutrients. For a complete list, see Nutrient Requirements of Swine, 10 th Revised Edition, National Research Council 2 Pigs weaned at less than 28 days of age. This diet should contain 25 to 75 percent milk products. 3 This diet should contain 5 to 25 percent milk products. 4 When adding large amounts of dried whey (10% or more), the added salt should be reduced (.25%) due to the high salt content of some whey products.

9 Table 2. Nutrient allowances for breeding swine 1 Percentage or amount per pound of diet Sows and gilts Nutrient Gestation Lactation 2 Boars Metabolizable energy, kcal 1,400 1,400 1,400 Protein, % Lysine, % Calcium, % Phosphorus, % Salt, % Iron, mg Copper, mg Zinc, mg Selenium, mg Vitamin A, IU Vitamin D, IU Vitamin E, IU Vitamin K, mg Riboflavin, mg Niacin, mg Pantothenic acid, mg Vitamin B 12, mcg Feed Required, lb This is only a partial list of required nutrients. For a complete list, see Nutrient Requirements of Swine, 10 th Revised Edition, National Research Council 2 The nutrient requirement of lactating sows increases as feed intake decreases. The nutrient content should be increased 8.3 percent for each pound below 12. (If sows will only consume 10 pounds/day, the levels of required nutrients should be increased 16.6 percent).

10 Table 3. Average analysis of ingredients used in swine diets 1 Nutrient M.E., Protein, Calcium, Phosphorus, Fat, % Fiber, % Lysine, Ingredient kcal/lb % % % % Alfalfa meal, dehydrated Animal fat Blood meal Corn, dent yellow Cottonseed meal, solvent Distillers dried grains with solubles Fish meal, Menhaden Grain sorghum Oats Oat groats (dehulled rolled oats) Peanut meal Rye Soybean meal, dehulled Soybeans, roasted or extruded Sunflower meal Triticale Wheat Wheat bran Wheat midds Standard reference values modified to reflect Southeastern feedstuffs

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