12 



MISCELLANEOrs PAPEES. 



Table II. — Chemical composition of the different parts of fruits of cacti. 



It must be undertood that we have analyzed here but few fruits 

 aside from those which are of more value for forage than they are as 

 food for man. None of the cylindrical-jointed species and but few 

 of the native prickly pears of the United States bear edible fruits. 



A BALANCED RATION OF PRICKLY PEAR. 



To determine in just what proportion cactus should be fed w4th 

 other foods to produce a balanced ration, it is necessary to know the 

 amount of digestible nutrients contained in the cactus, as well as 

 those of the food or foods with which it is to be fed. This has been 

 determined for most foods, but unfortunately there are as yet no such 

 data for the cacti. It is hoped to be able soon to obtain the coeffi- 

 cient of digestion for Opuntia llndheimeri. P'or the present, all that 

 can bedone is to assume this digestibility coefficient to be the same as 

 that of some food as similar in chemical composition and properties to 

 the cacti as possible. It is somewhat difficult to secure a green fodder 

 very similar in character to cactus, but perhaps its digestion coefficient 

 wdll not be missed very far by assuming it to be the same as that of 

 immature green corn fodder. By using the coefficient for tliis fodder 

 the nutrients in Opuntia lindheimen are found to be: Protein, 0.47 per 

 cent ; fat, 0.26 per cent ; carbohydrates, 7.85 per cent. This being the 

 case, cactus Avould have a nutritive ratio of 1:18, a ratio wdiich 

 according to the best authorities \vould prohibit its use alone for any 

 feeding standard. The nutritive ratio for a standard ration varies 

 from 1:4 to 1:12, depending upon the age, character, and kind of 

 animal to be fed, as well as the object of the feeding; that is, whether 

 it is desired to produce work, flesh, or milk. 



If the object of feeding is to produce milk, a cow giving a heavy 

 yield of milk should, according to the best authorities, be fed about 

 25 to 30 pounds a day of organic matter, containing from 1.8 to 2 

 pounds of digestible protein, from 0.4 to 0.7 pound of digestible fat, 

 and 11 to 13 pounds of digestible carbohydrates, making a nutritive 



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