THE VITAMINS. The vitamins are classified as fat-soluble and water-soluble

The vitamins are classified as fat-soluble and water-soluble. The fat-soluble group includes vitamins A, D, E and K and the water-soluble group – vitamin C and the numerous members of the vitamin B complex.

Vitamin A is found in the liver oils of fish and animals. It is formed in the animal body from pigments called carotenoids. Dried grass of high quality is the best source of the vitamin. The main signs of vitamin A deficiency in young cattle are failure to thrive, night blindness and, later, total blindness due to damage of the optic nerves. In all animals secondary bacterial infections occur where the deficiency is prolonged, and it may lead to the death of an animal.

Vitamin D is present in cod-liver oil, which was essential to the prevention of rickets. Vitamin D, in fact, is often called the anti-rachitic factor. Rickets, the disease due to vitamin D deficiency, is characterized by a failure of the animal to lay down calcium and phosphorus in its bones. Rickets can occur as a result of a deficiency of calcium or phosphorus in the diet.

Vitamin E is a dietary ingredient essential for the reproduction of rats.

Vitamin C is required only by guinea-pigs, humans, and the higher apes, where a lack causes scurvy. Farm animals and birds manufacture the vitamin in their systems.

The remaining water-soluble vitamins are all grouped into vitamin B complex. Member of the vitamin B complex is required by adult ruminants. Before the rumen of the young animal is fully established it needs a source of these vitamins in its ration.

UNIT 17.