Nutrition
PIH-2
pork industry handbook
PURDUE UNIVERSITY • COOPERATIVE EXTENSION SERVICE • WEST LAFAYETTE, INDIANA
Vitamins for Swine
Authors
Robert C. Thaler, South Dakota State University
Richard C. Wahlstrom, South Dakota State University
Reviewers
T. R. Cline, Purdue University
Robert Easter, University of Illinois
William G. Luce, Oklahoma State University
Vitamins are one of the classes of nutrients required for normal metabolic functions in the animal body. They are required in much smaller amounts than most other nutrients and can be referred to as micronutrients. Vitamins are not used as energy sources or structural components, but are generally required as co-enzymes in metabolic reactions. Some vitamins can be synthesized within the pig’s body in sufficient quantities to meet the pig’s requirement. Others are present in adequate amounts in feedstuffs commonly used in diets. However, the potency of certain vitamins in feedstuffs is greatly reduced during storage and drying. Therefore, several vitamins should be added to swine diets to obtain optimal performance. Attention to vitamin needs is more critical today than previously because of the simpler diets containing fewer ingredients, and the trend toward modem housing which has reduced both coprophagy and access to pasture. Young, lush, green grass or legumes are good sources of many vitamins.

Vitamins Needed
Those vitamins that should be added to swine diets can be divided into two groups:
•	Fat soluble vitamins
Vitamin A
Vitamin D
Vitamin E
Vitamin K

•	Water soluble vitamins
Riboflavin
Pantothenic acid
Niacin
Vitamin B12
Choline
Folic acid
Biotin
The need for addition of biotin to practical diets is not well-established.

Several other vitamins function in the pig’s body. These include pyridoxine (B ), thiamine and vitamin C (ascorbic acid). There is only questionable evidence that pigs fed practical diets will benefit from the inclusion of supplements containing these vitamins. Therefore, it is not recommended that they be routinely added to swine diets.

Vitamin A. The vitamin A needs of swine can be met by either vitamin A or B-carotene. Vitamin A does not occur in plant products, but the plant pigment, B-carotene, can be converted to vitamin A in the intestinal wall of the pig. Good, natural sources of B-carolene include green pastures and green, leafy alfalfa hay or meal. Yellow com contains B-carotene but is not a dependable source because much may be destroyed in storage. Therefore, in formulating diets, the B-carotene concentration of com is disregarded. Other cereal grains are low or devoid of B-carotene.

Deficiency symptoms in growing pigs are incoordinated movement, weakness of the back, paralysis, night blindness and total blindness. Sows may fail to come into estrus, have poor conception rates, resorb their fetuses, and have weak pigs at birth or pigs bom dead with various deformities. Sterility may occur in boars.

Vitamin D. Swine that have daily access to sunlight produce their own vitamin D. However, fortification of diets with vitamin D is necessary when pigs are fed inside. Also, most feedstuffs are practically devoid of vitamin D except for sun-cured hays. Both vitamin D , the form found in plant products, and vitamin D , the animal product form, have the same value for swine.

Vitamin D is needed for the efficient absorption and metabolism of calcium and phosphorus and therefore is required for normal calcification of bones. A deficiency in young pigs results in rickets, stiffness and lameness, enlargement of the joints and general unthriftiness. In mature animals, fractures of the bones are common. Excessive levels of vitamin D in the feed or as an
Cooperative Extension Work in Agriculture and Home Economics, State of Indiana, Purdue University and U. S. Department of Agriculture cooperating, H. A. Wadsworth, Director, West Lafayette, IN. Issued in furtherance of the Acts of May 8 and June 30, 1914. It is the policy of the Cooperative Extension Service of Purdue University that all persons shall have equal opportunity and access to its programs and facilities without regard to race, color, sex, religion, national origin, age, or handicap.