IT 8 PASTORAL AND AGRICULTURAL BOTANY 



water, 1.5 per cent, ash, 10.1 per cent, crude protein, 2.0 per cent, fiber, 

 70.9 per cent, nitrogen free extract and 5.0 per cent. fat. 



Nature of Feeds. In the consideration of feeds, it is important to 

 differentiate between those which have a coarse, bulky character and 

 others which are more concentrated and nutritious. Accordingly the 

 terms " roughage" and "concentrates" are used. Roughage represents 

 the coarser feeding stuffs, which have a considerable amount of fiber and 

 therefore, smaller amount of digestible matter. Roughage is necessary 

 to keep the animal in good condition, as it is an aid to digestion. Con- 

 centrates are feeding stuffs of a concentrated nature, which have a small 

 amount of fiber and, therefore, a relatively large amoun t of digestible ma tter . 



Digestion. As the bodies of the domestic animals are composed 

 of protein, fat, mineral substances, dry substances and water, these must 

 be supplied in the food which the animal consumes. The changes, which 

 the food undergoes within the digestive tract of the animal to prepare 

 it for absorption and for utilization by the animal bodies are known as 

 digestion. Digestion is accomplished by the enzymes, or feiments, pro- 

 duced by the glands of the mouth stomach, pancreas, the small intestines 

 and the liver. Bacteria found in various paths of the alimentary canal 

 help to break down the food also, especially the fibrous materials. A 

 nutrient is any food constituent, or group of food constituents, that help 

 in the support of animal life. There are three primary classes of nutrients, 

 viz., crude protein, the carbohydrates and the fats. Air, water and min- 

 eral matter might also be classed with nutrients, but are usually excluded 

 from this category. WHen it has been found that the above substances 

 are digested by the domestic animals, they are termed digestible nutrients. 



Rations. A ration on the farm is the feed allowed, or set apart, to 

 support a given animal for a day of 24 hours, whether all of the food is 

 given at one time, or is divided into portions given at intervals throughout 

 the day. There are several kinds of rations recognized in the feeding of 

 animals. A complete or a balanced ration is the feed or combination of 

 food stuffs which will supply the several nutrients, crude protein, carbo- 

 hydrates and fats in the right amounts, and in the right proportions with- 

 out excess of any nutrient, so as to nourish a given animal for one day. 

 A maintenance ration is one that furnishes enough, but no more, of each 

 and all of the several nutrients than is required to maintain a given resting 

 animal, so that it will neither gain nor lose in weight. 



As the character of the alimentary tract with its associated "glands 

 and other organs are considered by the ana tomist and as the processes of 



