82 



of value in the case of a ration for dairy cattle, 

 from 40 to 70 lb. of pear being used along with 

 plenty of other nutritious food for each animal. 

 He stated that cattle, sheep, and goats soon become 

 accustomed to singed Opuntia, though scouring 

 is apt to occur. In Texas, cotton-seed meal is 

 generally added to a pear diet, while in Colorado 

 the cane cactus {Cylindr opuntia, spp.) is usually 

 fed alone. 



Next year there appeared his bulletin giving 

 the results of his feeding experiments (1906), 

 both beef cattle and dairy cattle being used. The 

 milk yield was found to be in no way adversely 

 affected by the use of a roughage of prickly-pear. 

 Animals fed on chopped Opuntia together with 

 cotton-seed meal were found to have gained in 

 weight. 



In the same year C1906) Griffiths and Hare 

 published a long article entitled "Prickly Pear 

 and other Cacti as Pood for Stock, II." In it 

 are abundant data regarding the chemical 

 analyses, as well as short accounts, of a large 

 number of species examined, amongst them being 

 some which occur in Queensland, viz., 0. inermis, 

 0. monacantha, and 0. imbricata. It was found 

 that the stems of the low-growing Texan species 

 were of more value than those of the tall tree 

 forms from Mexico, as they were far less woody 

 and more succulent. However, it was also found 

 that the old stems of the commonest Texan 

 species, 0. lindheimeri, contained less water and 

 more crude fibre and had a less food value than 

 the younger growth, but the lower water content 

 of the stems was a decided advantage when deal- 

 ing with such succulent feed. Though the fruits 

 of cacti were usually found to possess more fat 

 and protein than the stems, yet it was noticed that 

 the seeds contained nearly all the food material 

 of the fruit, and as they are passed through cattle 

 undigested, this food was not available. Of 

 course those fruits which are rich in sugar have 

 considerable nutritive value. The cane cacti were 

 found to have a greater relative food value than 

 the flat Opuntias, as they contained more pro- 

 tein, fat, and nitrogen-free extract. They were, 

 however, generally drier and contained more 

 fibre, and were therefore less suitable for 

 ordinary feeding. 



The question of forming a balanced ration 

 for cattle is also discussed. Assuming that the 

 coefficient of digestion for 0. lindheimeri is the. 

 same as that of immature green fodder, the nutri- 

 ents in that species were calculated as protein .47 

 per cent., fat .26 per cent., carbohydrates 7.85 

 per cent., the nutritive ratio of the plant being 

 1 : 18. The ratio for a standard ration varies 

 between 1 : 4 and 1 : 12 according to the animal 

 and to the object of feeding, whether for work, 

 beef, or milk. Hence prickly-pear alone would be 

 too wide a ration. It is pointed out that in order 

 to produce milk the ratio should be from 1 : 5.5 

 to 1 : 7, and to provide the necessary digestible 

 fat, protein, and carbohydrate a cow would need 

 to eat about 400 lb. of pear, whereas not more 

 than 50 or 60 lb. should be fed daily on account 

 of the scouring which follows. The Opuntia could 

 be used as part of a fairly balanced ration thus : — ■ 

 40 lb. cactus, 10 lb. of wheat bran, and 12 lb. 

 of corn stover — a ration with a nutritive ratio of 

 1 : 7.7. Another ration suggested is as follows : — 

 60 lb. cactus, 14 lb. brewer's grain, and 1 lb. 

 cotton-seed meal — the nutritive ratio being 1 : 4.5. 

 This could be readily widened by the addition of 



coarse dry fodder. A balanced ration consisting 

 of prickly-pear and cotton-seed meal could not 

 be prepared, as too much cactus would have to 

 be fed, though it is usually got over by feeding 

 excess of the meal which becomes utilised by the 

 animal to supply the deficiency in carbohydrates 

 — an expensive method of supplying carbohy- 

 drates, and one which could be justified only 

 where the meal is cheaper than more starchy 

 foods. This paper was summarised the next year 

 (Griffiths and Hare, 1907 a). 



In an article (1908 a) dealing with " The 

 Prickly-pear as a Farm Crop, ' ' Dr. Griffiths again 

 referred to the value of cactus in dairy farming, 

 on account of the succulence and of the ease with 

 which a diet containing cactus as a roughage 

 could be balanced up by the addition of some 

 concentrated food, this succulence being available 

 at a time when other juicy fodder was not obtain- 

 able. Cattle, sheep, and goats were all found to 

 become fond of it. It was noted that 0. lind- 

 heimeri under cultivation produced annually 

 about 23 tons per acre, which would provide 

 enough roughage for a bovine. 



Dr. Hare carried out some " Experiments 

 on the Digestibility of Prickly Pear by Cattle," 

 publishing his work in 1908. He used 0. lind- 

 heimeri and found its average composition to be 

 as follows :" — ^Water, 83-41, ash 3-48, protein 0-75, 

 ether extract 0.31, crude fibre 2.64, nitrogen- 

 free extract 9-41, total organic matter 13-11 per 

 cent. As a result of his observations on feeding 

 it to steers, he determined the coefficient of diges- 

 tion to be — Protein 58.25 per cent., fat 67.90, 

 crude fibre 41-32, and nitrogen-free extract 

 82-59. The digestive nutrients (obtained as the 

 product of each nutrient by its coefficient) were 

 found to be — Proteids 0-45, fat 0-21, carbo- 

 hydrates 7.77— Nutritive ratio 1 : 18.3, which falls 

 far below both the European (1 : 5.4) and 

 American (1: 6.5) standard ratio for milch cows. 



In comparing the results obtained when 

 using the pear with those obtained with green 

 corn as a fodder, it was seen that the proteids of 

 the former were not quite as digestible as those 

 of the latter, though the fats were about the same 

 in each instance, and the nitrogen-free extract 

 more digestible in the case of the pear, but the 

 cruae fibre less so. The total digestive nutrients 

 were thus about the same in both, though slightly 

 in favour of the cactus. He also found that when 

 pear was fed along with cured fodders or grains 

 the digestibility of both seemed to be increased. 

 In one experiment the animals gained weight, but 

 in another set of experiments the beasts lost 

 weight. As a satisfactory ration for a 1,000-lb 

 milch cow he suggested 50 lb. prickly-pear, 10 lb. 

 wheat bran, and 10 lb. lucerne, this having a 

 nutritive ratio of 1 : 5.46. The tendency to- 

 scour, as a result of feeding on a ration of 

 prickly -pear and cotton-seed meal such as is com- 

 monly used in Texas, could be checked either by 

 giving some coarse feed in addition or else by 

 allowing cattle the run of a dry-grass pasture. 



As early as 1895 Goss (p. 49) had suggested 

 that lucerne should be added to prickly-pear diets 

 in order to increase the amount of nitrogen in the 

 ration. 



Uncultivated Pricldy-pear as Fodder. — In 

 a bulletin entitled " Cacti in New Mexico," 

 E. 0. Wooten (1911) attempted to awaken 

 the interest of New Mexican ranchmen in 



