48 MANUAL OF FARM ANIMALS 



CONDITIONS INFLUENCING DIGESTION 



The changes that the food undergoes in the digestive tract 

 during digestion are beyond the control of the feeder. They 

 proceed in accordance with fixed laws. The feeder, however, 

 can manipulate the food or change the conditions under which 

 it is fed so that the completeness of digestion is modified. 



Palatabiliiy. — In the case of most foods, anything that adds 

 to their palatability will promote digestion. While an agreeable 

 flavor or taste adds nothing to the energy of a food, the more it is 

 relished the greater will be the flow of the digestive juices, the 

 more thoroughly the food will be acted on by them, and the 

 more completely the nutrients will be dissolved and digested. 



Palatability, therefore, is an important factor in feeding, as it 

 promotes a more vigorous action on the part of the digestive 

 organs, which result in a more complete digestion of the food. 



Time of harvesting. — The effect on digestibility of the time 

 of harvesting plants is great. The time to harvest a plant so 

 as to get the maximum amount of digestible material will depend 

 much on the part of the plant that is to be used for food. In the 

 case of hay, much of the food material is transferred from the 

 stalk to the seed as the plant ripens. These seeds are so small 

 and hard that they are not digested by the animal; hence hay 

 that is cut when ripe is not so digestible as that cut before the 

 seeds ripen and while the food materials were yet in the growing 

 parts. Again, the riper the plants the more crude fiber they 

 contain, and this we have already seen is mostly undigestible. 

 In the case of corn, it is the seed that is used as food, and in this 

 case the plant should not be harvested till the food materials 

 have passed from the stalk into the seed. Therefore hay plants, 

 or those plants of which the stems and leaves are used, should be 

 cut when green, and grain plants, or those plants of which the 

 seeds are used, should be cut when ripe. 



Grinding the food. — Grinding certain kinds of foods promotes 

 digestion by increasing the surface exposed to the action of the 



