Aug. i6, igis Prickly-Pears as a Feed for Dairy Cows 431 



removing them is by means of singeing with a strong gasoline torch, as 

 shown in Plate LXI, figure i, or by burning the spines off over a brush 

 fire, if but a small quantity of prickly-pear is to be fed. Chopping 

 machines have been, used with some success to render the spines practi- 

 cally harmless, but the practice of singeing with the gasoline torch is 

 economical in both labor and the greater utility of the prepared feed 

 (4, p. 13). By using the gasoline torch in an average of three trials at 

 Brownsville, Tex., by the Bureau of Animal Industry, it was found that 

 50 minutes' time and i % gallons of gasoline were required to singe i ton 

 of the spiny prickly-pear. These trials were conducted with a 2-year 

 growth of the plant that yielded at the rate of about 80 tons an acre per 

 annum. With the class of labor obtainable and the price of gasoline at 

 that time, it was estimated that prickly-pear could be singed at a cost 

 of approximately 50 cents a ton. 



There are two methods of feeding prickly-pear from which the spines 

 have been removed: The cattle may graze the standing plant down to 

 the heavier stems or it may be cut down and hauled to the feed lots. 

 The first method requires less labor, but is more wasteful and is not advis- 

 able, especially with a cultivated plantation, unless the supply of prickly- 

 pear is plentiful. If the cacti are removed to feed lots, the cost of feeding 

 will depend upon the proximity of the lots and the accommodations for 

 feeding. One man with a team can haul and feed from 3 to 6 tons a day 

 (PI. LXI, fig. 2, and LXII, fig. i). 



A test on a small scale showed that prickly-pear was not suitable for 

 making silage. At the end of 30 days only the small spines had been 

 softened; furthermore, the cows would not eat it. 



COMPARATIVE VALUE OF SPINY AND SPINELESS PRICKLY-PEAR 



The spineless varieties of prickly-pear are relatively free from thorns 

 or spines. They have practically the same chemical composition as the 

 spiny varieties and are probably of equal value for feeding purposes. 

 However, they are less hardy than the spiny varieties and more subject 

 to injury from low temperatures, so that the area in which they can be 

 successfully grown is much more restricted than that of the spiny varie- 

 ties. But little accurate information is obtainable as to the yield of the 

 spineless varieties. In work conducted at Chico, Cal., by one of the 

 writers (6, p. 9) an annual yield of from 20 to 25 tons an acre was obtained. 

 These yields were obtained with expert cultivation and by maintaining a 

 perfect stand. At Brownsville, Tex., where the work reported in this 

 paper was conducted, there is no authentic record of the yield of the 

 spineless varieties. It is known, however, that because of insects and 

 low temperature the yield is much less than that of the native spiny forms. 



The spineless and the spiny varieties are apparently of equal value for 

 milk production. During the latter part of the second year's work the 

 spineless prickly-pear was substituted for the spiny in the ration of all 



