Lesson 3

1. Mineral Requirements for Growth

As the large amounts of minerals, especially calcium and phosphorus are required to build the skeleton and other parts of the body, normal growth cannot be expected unless the ration amply meets these mineral needs. A lack of minerals may be much more serious to a young animal than a lack of total digestible nutrients.

If the ration is very deficient in calcium or phosphorus rickets may result, and the animal may be permanently crippled or deformed. Also, the skeleton may be seriously reduced in strength, and the bones may be so fragile that they will break under ordinary stresses and strains in later life.

For calves, lambs and foals the best insurance against a lack of calcium is to feed sufficient legume hay throughout the winter and to provide good pasture during the growing season. Well-cured legume hay has not only an abundance of calcium; also sun-cured hay is the best source among common feeds of vitamins, which the animals must have in order to assimilate the calcium and phosphorus in their rations.

If suckling pigs are not on pasture, there may be anemia which is caused by a lack of iron.

Vocabulary List

require (v) требовать, нуждаться в чем-либо

amply (adv) - достаточно

tomeettheneeds- удовлетворять потребностям

a lack of something - недостаток (чего- либо)

digestible(а)- легко усваиваемый, перевариваемый

nutrient(n)- питательное вещество

rickets (n)- рахит crippled (p.p.) - искалеченный

fragile(а) - хрупкийordinary(а) - обычный

insurance (n)- гарантия

stress (n) - напряжение iron (n)- железо

foal (n) - жеребенок legume (n) - боб, бобовые

throughout the winter - всю зиму pasture (n)- пастбище

well-curedhay- хорошо высушенное сено

sucklingpigs- поросята-сосуны, подсосные

Exercise 1. Translate and render the contents of each paragraph of the text.

Exercise 2. Answer the questions:

1. What is required to build the skeleton and other parts of the body?

2. When may rickets result?

3. What is the best insurance against a lack of calcium?

4. What is a good source of calcium?

5. What can a lack of iron cause in suckling pigs?

Exercise 3. Translate following sentences into English:

1. Для построения скелета требуются кальций и фосфор.

2. Рахит может быть результатом рациона бедного кальцием и фосфором.

3. У этих животных нельзя ожидать нормального роста.

4. Рацион должен включать эти минеральные вещества.

5. Скелет может быть сильно ослаблен.

6. Кости могут быть такими хрупкими, что будут ломаться при обычной нагрузке.

7. У поросят анемия вызывается недостатком железа в организме.

B. Vital Functions of Minerals

Minerals have many vital functions in the body. The skeletons of vertebrate animals are composed chiefly of minerals (nearly all calcium and phosphorus), and minerals are essential constituents of the soft tissues and fluids of the body.

Phosphorus is a vital ingredient in the proteins that characterize the nuclei of all body cells, and also is a component of certain other important proteins such as the casein of milk. The phospholipids, which are phosphorus-containing milk fat-like substances, are essential parts of all living protoplasm. The power of the blood to carry oxygen is due to hemoglobin, the iron-protein compound in the red blood corpuscles.

The acidity and alkalinity of the digestive juices is due to mineral compounds. Thus, the acidity of the gastric juice in the stomach, which is necessary for the action of the enzyme, pepsin, is due to hydrochloric acid, derived from sodium chloride and other chlorides that are present in the blood.

The osmotic pressure which is necessary for the transfer of nutrients and waste products through the cell walls is largely dependent on the concentration of mineral salts in the lymph and in the cells.

A serious lack of calcium in the blood such as may occur in milk fever of cows and in certain advanced cases of rickets is the cause of convulsions and tetany.