The Spectator., 1915-11-09

c1oe later to undertake the course- ;. II: Miller. Director Cooperative Ex- tension Work.
 ]. Principles of Animal Nutrition.
 In order to fully appreciate the i'm portance of animal production one must consider that as human beings we depend upon the raw soil for food and ra1ment. It would indeed be difficult matter had not kind provi- dence provided plants and animals to aid us In our struggle for existence. The plant, with its root system pene- tsates the soil and with the aid of va. r1ous agencies, is able to gather for ltseir rom among the eighty or more elements those which are peculiar to It's needs and with the aid of the suns rays elaborate them into it's body and fruit. The animal. on the other hand. browses the growing plants or con- sumes the gathered forage, and by means of Its process of digestion is capable of reducing plant life into forms so simple that they may enter the animal body and there take on the forms of flesh. fleece and power.
 Because of this close relationship existing between plants and animals. it Is therefore not at all se1angs that upon analysis by the chemist, plant and animal tissues contain similar compounds which for our convenience have been grouped into four groups: namely. ash or mineral matter pro- tein, carbohydrates and fats. From the standpoint of animal production we will confine our considerations to these groups of compounds.
 The muscle or flesh. hide. hair, blood and such parts of the animal body are composed largely of com pounds found in the group known as proteins. The development of sucn tissues takes place largely during the growth of the animal, as each of thess tissues Is made up of many cells which during growth increase in size and In number. After the animal reaches maturity only sufficient amounts of these compounds are nee. essary to replace wear and tear. The logical conclusion would be that grow ing animals should have foods rich ,a protein compounds, as very pecu- liar condition exists whereby only pro- tein compounds of plant or animal foods can form protein compounds in the animal body Compounds from the other three groups can not serve the purpose. We find in the plant king dom that certain classes of plants contain a greater percentage of these protein compounds than others. Fore most among them is the class of plant known as legumes Legumes such as alfalfa. clover, peas, beans, vetch and other should because of their protein content be desirable feeds for growing animals. Factory by-products such as oil meal, cotton seed meal, gluten meal. dried brewers grains. wheat bran, and others are al. so rich in protein compounds.
 The ash or mineral matter is found largely in the skeleton of animals As with protein the greatest demand for mineral matter such as lime. phos- phorus and others comes during the growing period of the animal because 1t is then that the rapid increase in size calls for a rapid increase of the bony framework
 Carbohydrates which includes starches, sugars, and fiber are not found except in very small quantities in the animal boly, but are the main source of fat and heat in the body. When fed in moderate quantities they are stored in the liver and muscle tis- sue in the form of glycogen or animal starch and used for maintaining the body temperature. If fed in large Quanties they are changed into the more stable fat, For mature animals where the object Is to fatten or dur. ing seasons of the year where tempe ratures are low. the feeding of feeds rich in carbohydrates would be sd. vissble. Most of our cereal grains and our coarse folders are rich in carbo- hydrates. During work great deal of heat is evolved. so that carbohy- drates are more economical as a rule for work stock to a certain extent than protein. Protein can however, if 1 fed in excess be changed into fat, but it is not economically used in thst way, Fats serve much the same pur. ! pore as carbohydrates in the animal body. and if fed in large quantities