432 Journal of Agricultural Research voi. iv, no. 5 



the cows fed with this plant. There is apparently some difference in 

 taste between the raw spineless and the singed spiny prickly-pear, as some 

 of the cows ate the former with somewhat less relish for the first few days 

 after the change was made. This was likewise true when the spiny 

 prickly-pear was again fed, but in both cases the two varieties were eaten 

 with equal relish after the first few days of feeding. No change in 

 production or body condition was caused by the change in the kind 

 of prickly -pear fed, and the spineless had the same laxative effect 

 as the spiny variety. 



The cost of harvesting and feeding the spineless kind would differ from 

 that of the spiny varieties only in the cost of singeing. The spineless 

 prickly-pear, unlike the spiny form, could not be harv^ested by grazing, 

 for the amount to be fed daily could not be controlled, as is the case 

 with the spiny forms. The waste of feed and destruction of plants by 

 stock in the field would be so great as to make that method of harvesting 

 less economical than cutting and hauling the cacti to a feed lot. 



SUMMARY 



The average analysis of prickly-pear fed in these experiments was 

 as follows: Water, 91.30 per cent; crude protein (N X 6.25), 0.58 percent; 

 albuminoid protein, 0.29 per cent; ether extract, 0.12 per cent; nitrogen- 

 free extract, 4.67 per cent; crude fiber, 1.16 per cent; ash, 1.76 per cent. 



Prickly-pear was found to be a very palatable feed for dairy cows, 

 even when it formed the major part of the roughage ration, and 100 to 

 150 pounds were consumed per cow per day. 



The prickly-pear ration caused an increase in the quantity of milk 

 produced, a decrease in the percentage of fat in the milk, and a decrease 

 in the total production of fat. The reduction in the percentage of fat 

 became more pronounced as the quantity of prickly-pears in the ration 

 increased. 



Assuming the feeds to have these percentages of dry matter — prickly- 

 pear, 10; sorghum hay, 80; sorghum silage, 25; and cottonseed hulls, 

 90 — and considering the nutritive values to vary in direct proportion to the 

 content of dry matter, i pound of sorghum hay was equal to 15.9 pounds 

 of prickly-pear when that plant was fed in large quantities and to 

 10. 1 pounds of prickly-pear when it was fed in moderate amounts. One 

 pound of sorghum silage was equal to 2.6 pounds of prickly-pear, and 

 I pound of cottonseed hulls was equal to 5.8 pounds of prickly-pear. 



When prickly-pear in moderate amounts was substituted for a 

 part of the dry roughage, it appeared to have little effect on the 

 digestion of the other ingredients of the ration; when substituted in 

 large amounts it depressed the coefficient of digestion, although not to 

 any great extent. 



As the result of maintenance trials conducted during these experiments, 

 it is believed that mature Jersey cows can be maintained on a daily 



