VENTILATION. 



VENTILATION. 



required, more fatty food must be furnished; and 

 of all substances for effecting this object, linseed- 

 cake, and maize are perhaps the best. 



It is of great importance to attend to the state 

 in which food is introduced into the stomach of 

 animals. Indian corn, for example, given with- 

 out mixing with other food, will not be so readily 

 digested. The proper preparation of food for 

 animals is a branch of agricultural knowledge 

 which has been found highly profitable to the 

 farmer. By mixing different kinds of food, the 

 requirements of the animal are best met. Cut 

 straw or chaff is an admirable substance with 

 which to mix other more nutritious materials. 

 rendering these more readily digested and nourish- 

 ing, besides making the food go further. Malt is 

 often employed with great advantage, mixed with 

 other food. Other influences, such as warmth, 

 shelter, ventilation, and quiet, exert a great 

 effect in promoting the thrift and welfare of 

 animals. 



The amount of nutriment found in different 

 varieties of the food consumed by the farmer's 

 live stock, has been referred to under the head 

 FOOD, where some interesting facts will be found, 

 chiefly derived from the researches of Davy. It 

 is a subject to which still more recent inves- 

 tigations have given additional interest. The 

 proportions in which the several elementary 

 substances exist in 100 parts of some of the 

 most commonly cultivated grains and products 

 of the farm, are represented in the following 

 table from Prof. J. F. W. Johnston's Lectures. 



likewise contain a substance called gluten, but 

 in quantities varying very much, as may be seen 

 by running the eye down the 4th column of the 

 table ; the greatest proportion of this and albu- 

 men being found in beans, which explains their 

 highly nutritious qualities. Even pea-straw is 

 very rich in these materials, which makes them 

 valuable provender, where other kinds of straw 

 are almost worthless. Of oil or fatty matter, 

 wheat and barley have very little, whilst in 

 oats and Indian corn, oil abounds. The root 

 crops and straws have very little. Plants take 

 in, through their leaves and roots, the carbonic 

 acid and other materials, the changes in which 

 produce the starch, gluten, and fat to be found 

 in them all, and which go to nourish animals. 



It forms, says Mr. Karkeek, in his "Essay on 

 Fat and Muscle" (Jour. R. A. S. vol. v. p. 2-19), 

 a curious and interesting subject for the feeder to 

 ascertain the respective quantities of the fleshing 

 and fattening properties contained in an acre of 

 the different crops commonly used in the rearing 

 and feeding of stock. The following acreuble 

 tahle of nutrition has been constructed chiefly 

 from Professor Johnston's calculations; the pro- 

 portions of gluten, &c., from Boussingault's ana- 

 lysis, which indicate \&Jleshing properties ; and 

 the proportions of starch, gum, and sugar, the 

 fattening properties : 



Some of the numbers in the above table are 

 given as mere approximations, especially those 

 referring to buckwheat and fatty matter, which 

 last is very uncertain. 



It hence appears that water enters into the 

 composition of every vegetable product, wheat 

 containing 13 per cent., the turnip 88 to 90 per 

 cent., exhibiting the strong contrast between 

 grains and roots. The second column represents 

 woody fibre, straw and husks, parts of plants 

 which animals cannot digest, and from which 

 they consequently derive no nourishment. In 

 wheat and other grains, the proportion of this 

 varies from 10 to 20 per cent. In the column 

 designating the proportions of starch, gum, and 

 sugar, the grain of wheat exhibits about 5"> per 

 cent., Indian corn 70 per cent., Indian corn stalks 

 32 per cent., rice 75 per cent., &c. All grains 



Another table showing the nutritive properties 

 per acre of the ordi?iary crops of the farmer has 



j been given by Mr. Hyett, and will be found at 



j the head of the next page. 



The tables just given from analyses made by 



j Prof. J. F. W. Johnston, and other eminent 



j chemists, show the proportions of water, with 



I those of the several dry organic constituents, as 

 well as the ashes or saline matters contained in 

 many of the articles of food with which the far- 

 mer is most familiar. From these it may be 

 seen that it is very important for the economical 

 management of live-stock to know the amount 

 of water as well as of the organic and nutritive 

 ingredients which each kind of food contains. 

 Thus we find that in giving a pig 1 00 Ibs. of po- 



| tatoes, we actually give it about 75 Ibs. of wa- 

 ter. But in giving it 100 Ibs. of Indian corn, we 



, contribute only about 14 Ibs. of water, nearly 

 all the remaining 80 Ibs. being nutritious matter. 

 As already observed, the table just given from 

 Professor J. F. W. Johnston shows the propor- 

 tion of woody fibre freed from the nutritious sub- 

 stances, well known to be contained in greater or 

 less proportion in husks, straw, &c. This woody 

 fibre, as it cannot be digested by animals, 

 must therefore be deducted from the amount of 

 nourishment. It constitutes half the amount of 

 wheat and rye straw, whilst it makes but 30 per 

 cent, of ordinary meadow grass hay, and only 25 

 per cent, of clover hay, 



'087 



