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A group of swine (hogs)

Efficient and profitable swine production depends on understanding nutrition because nutrition represents 60% to 75% of the total cost of swine production. In general swine will not meet their genetic potential without proper nutrition. The following information provides the basic terms and concepts of swine nutrition.

Proper swine nutrition begins with the six basic nutrients water, carbohydrates, fats, protein (amino acids), minerals, and vitamins. Each of these nutrients play a vital roll in maintenance, growth, reproduction, lactation, and other metabolic functions. Factors affecting nutrient requirements are lean growth rate, gender, energy density of the diet, environmental temperature, crowding, parity, stage of gestation, and various measures of sow productivity.


Water is the most essential of all nutrients. It is the least expensive, most consumed, and often most overlooked nutrient. An animal will die faster from lack of water than any other nutrient. The functions of water include body temperature regulation, nutrient transport, waste excretion, lubrication, and every metabolic reaction in the body. Consequently, water deprivation negatively impacts feed consumption, growth, feed efficiency, and milk production. Therefore, an adequate supply of quality water is required at each stage of production.

In general, water requirements are based on water to feed ratios (water:feed) which are 3:1 to 2:1 for nursery and grow-finish pigs. However, water requirements begin in the farrowing house with suckling piglets drinking 1.5 oz of water per day and increasing to 12 oz daily by weaning.

In gestation the sows water requirements range from 3 to 6 gallons per day. This is compared to lactating females who require 5 to 10 gallons per day due to the demands of milk production.

The factors influencing water consumption are water flow rate, water pressure, environment, management, facilities, and diet. The recommended water flow rates are presented in Table 1 and the ideal water pressure is 20 psi to facilitate drinker activation while controlling water wastage.


Table 1. Recommendations for Water Flow Rate

Flow rate, cups/min1-22-44
Time to fill a 16 oz bottle, sec60-12030-6030


Carbohydrates and Fats Supply Energy

Energy is not a nutrient, but a required biproduct resulting from the breakdown of carbohydrates, fats/oil, and excess proteins. Energy is required for maintenance, growth, reproduction, lactation, and all other body functions.

The main energy source for swine is carbohydrates found in cereal grains such as corn, milo, wheat, barley, and their co-products. The feed ingredients which supply carbohydrates/energy in swine diets also make up the largest percentage of the diet and total feed costs. Factors influencing energy requirement are body weight, genetic capacity for lean tissue growth, milk production, and environmental temperature. The energy content of the diet controls the amount of feed consumed when feed is offered free choice (ad libitum).

Additionally, fats (animals, saturated) and oils (plants, unsaturated) are considered  highly concentrated and digestible energy sources for swine. Fats and oils provide 2.5 times more energy than cereal grains. These ingredients are often used to improve the energy density of swine diets. This improvement results in  decreased in voluntary feed consumption, improved  rate of gain, and better feed efficiency. Additional reasons fats and oils are added to swine diets: reduce dust, improve diet palatability, and supply essential fatty acids. The addition of fat or oil to swine diets should not exceed 5%.

Protein and Amino Acids

The second most expensive component of the swine diet is the protein source. Amino acids (A.A.), normally supplied by dietary protein, are required for maintenance, muscle growth, fetal development, supporting tissues in gestating sows, and milk production in lactating sows. The main plant protein sources for swine are soybean meal, canola meal, sunflower meal, cottonseed meal, and field peas.

There are 22 A.A. which are the building blocks of all proteins and 10 are deemed essential, because they must be provided in the diet for normal growth and development. The 10 essential amino acids for swine are arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. The A.A. lysine and the remaining essential A.A.’s are normally provided in sufficient quantities in corn and soybean meal diets. The dietary requirements for lysine and crude protein based on stage of growth are presented in Table 2.


Table 1. The dietary lysine and true protein requirement based on the stage of growth.

DietLysine, %Crude Protein, % Body Weight, lbs.



Minerals constitute a small percentage of swine diets, but their importance should not be over-looked. However, due to mineral deficiencies in feedstuffs, the required minerals must be provided in the diet as a mineral supplement to ensure requirements are met.

Minerals serve  structural, metabolic, and regulatory functions in the body. Adding excess minerals is costly and may cause toxicity while deficiencies result in decreased productivity. Therefore, mineral nutrition must be precise.

Minerals are classified as macrominerals or microminerals based on quantity required in the diet. Macrominerals calcium, phosphorus, sodium, chlorine, magnesium, and potassium need to be supplied in larger amounts and generally expressed as a percentage (%) of the diet. Microminerals (trace minerals) zinc, copper, iron, manganese, iodine, and selenium need to be supplied in smaller amounts and are expressed as parts per million (ppm or mg/kg) of the diet.


Vitamins are required for growth, development, maintenance, and reproduction. Vitamins may be made by the animal or delivered in the diet. If vitamins remain inadequate, they must be added to the diet in the form of a vitamin premix to avoid deficiencies and reach optimal production.

Vitamins are classified as fat or water-soluble vitamins. Fat-soluble vitamins A, D, E, and K are mainly involved in tissue development, calcium and phosphorus metabolism, antioxidant defense, and blood coagulation, respectively. The water-soluble B-complex vitamins are required as co-enzymes in several metabolic processes. The B vitamins commonly added to swine diets are riboflavin, niacin, pantothenic acid, and vitamin B12. Additionally, folic acid, pyridoxine, choline, and biotin are included in sow diets to support reproductive performance.


You can’t reach production goals when nutritional requirements are not the focus.

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