Text № 10 feeds of animal origin.

It is well known that the proteins of milk have an especially high nutritive value. Casein, which forms over three –fourths of the protein in milk , is but slightly inferior in value to the entire mixture of proteins milk contains.

Lactalbumen , or milk albumin ,which forms most of the remainder of the milk protein , is also of high nutritive value. The protein of whey is chiefly lactalbumen.

The proteins of meat ,fish, and eggs are also of unusually high nutritive value , a fact that is of great importance in human nutrition. Those of eggs and fish are probably about equal to milk proteins in efficiency , and meat proteins rank but slightly below. In live stock feeding the meat and fish by-products are excellent protein supplements , especially for swine and poultry.

Animal tissues that consist mostly of gristle and connective tissue are apparently of considerably lower nutritive value than muscles or most glandular tissues , such as the liver or kidneys.

If animal by-products are subjected to too high a temperature during the manufacturing process , the digestibility and the nutritive value of the proteins is decreased somewhat. Therefore the protein of vacuum-dried fish meal is of greater value than that dried at a higher temperature.

Text №11 straw.

Straw is akin to hay as a food , but is much more bulky and fibrous. Straw consisting of the mature stems and leaves has relatively little protein , starch or fat ,while the content of fibre or cellulose is high.

The great bulk of straw is an unsuitable food , at least in large proportions , for heavy milking cows , hard working horses ,calves, lambs or foals. For dry cattle and slowly fattening animals straw is useful part of the ration. The actual nutritive value and palatability depends on the type of crop from which it is made.

The straws of barley and wheat ,because of the advanced stage of ripeness at which they are cut , are somewhat less valuable than the straw of oats which is usually cut in a less ripe condition.

Straw from oats cut at a fairly green stage contains an appreciable amount of sugar which renders it palatable to stock. About four pounds of straw are in nutritive value the equivalent of a pound of barley.

Straw is usually used for bedding.

Text № 12 silage.

When green forage from a suitable crop is placed in a compact mass in a silo the following characteristic changes take place which convert it into silage. For a time the living plant cells continue to respire , or breathe , rapidly using up the oxygen in the air within the mass and giving off carbon dioxide (carbonic acid gas)within 5 hours practically all the oxygen has disappeared , and this prevents the development of molds, which are unable to grow in the absence of oxygen.

Certain acid-forming bacteria multiply enormously in the silage , as conditions are favourable for their growth. At the end of 2 days each gram of silage juice (about one-fourth of a teaspoonful) may contain one hundred billion bacteria. These bacteria attack the sugars in the green forage ,producing organic acids, chiefly lactic acid(the acid of sour milk) , with some acetic acid (the acid of vinegar) the traces of other acids. This production of acid is the most important change in the silage process ,for the acidity prevents the growth of undesirable bacteria, such as cause rotting or putrefaction.

When the acidity has reached a certain degree , the fermentation is checked , and finally the action practically ceased. If air doesn`t gain entrance into the mass of silage , it will then keep for long periods with but little change.