CATTLE FEEDING. 131 



* 



This dlfTorcnce of digestive .aptitude holds true for the other con- 

 stituents of fodder as well as for woody fibre. Making the digestive 

 faculty of the sheep equal to one hundred for all substances, we 

 would have the following approximations for our domestic animals.. 

 Kind of animal — Digestive aptitude for : 



Albuminoids. Fata. Ext. Carbohydrates. Woody fibre. . 



Sheep 100 100 100 100 



Horse 122 97 94 off 



Cow 100 109 97 105 



Ox 113 105 92 103 



It must not be forgotten that the age of the individual greatly affects 

 the digestive faculties ; that various races of the same animal show 

 powers of digestion which vary considerably', and that the tempera- 

 ment of the individual itself has much to do with the food digested 

 and assimilated. The ph^'sical condition of the food has also con- 

 siderable influence upon its digestibility, the older and tougher parts 

 of plants being much less useful than the 3'ounger parts. Great 

 care must be exercised in the harvesting of fodder crops, both as 

 regards the period of growth of the plants and the influence of 

 inclement weather upon the harvest. It is well known that rain is 

 very injurious to drying hay, as it washes away a large quantity of 

 very valuable nutrient matter. The influence of one constituent 

 upon the digestibility of the others is very great ; this can easily be 

 shown by the following experiment due to Haubner. He fed sheep 

 with one kilogramme (about 2 1-5 pounds) of cooked potatoes, 

 and one kilogramme, 250 grammes (about 2 | pounds) of wheat 

 straw, each. All the starch contained in the potatoes was full}' 

 utilized by every animal. To the above ration he added ^ kilo- 

 gramme (about 1 1-10 lbs.) more of potatoes, he then found that a 

 part of the starch was not assimilated and passed into the excre- 

 ment. By the addition of 125 grammes (a little over J lb.) of pea 

 meal to the mixture, he obtained a complete digestion of all the 

 starch [Ji'esent. The pea meal is rich in nitrogen, and in increasing 

 the quantity of albuminoids in the ration it increased the digestibility 

 of the carbohydrates, (starch, etc). 



The digestive relation of a fodder is the relation between the 

 albumioids and the cai'bohydrates it contains. The general formula 



for the digestive relation is „ or P : H in which P = albuminoids 

 and H carbohydrates. We see in Haubner's experiment the effect 



