May, 1909.] 



449 



Live Stock. 



that the disease is caused by a specific 

 micro-organism and is of an epidemic 

 character, though no organism has been 

 found, nor can the disease be trans- 

 mitted by inoculation or administration 

 of diseased bone. 



Now the proper ratio of phosphorus 

 pentoxide to lime in the food of 

 animals in order to favour bone forma- 

 tion and renewal, has not been directly 

 determined, but may be deduced from 

 one or two considerations. Thus, the 

 milk of animals may be assumed to 

 contain these ingredients in proper pro- 

 portion for the needs of young animals. 



Cows' milk contains on the average 

 about 0-17 per cent, of phosphorus pen- 

 toxide and 0-15 per cent, of lime, i.e., 

 in the ratio of 100 phosphorus pentoxide 

 to 89 of lime. In the bones of animals 

 the two substances are present in the 

 ratio of about 100 of phosphorus pen- 

 toxide to 150 of lime. 



According to Rothamstead experi- 

 ments, the amounts of the two substances 

 present in 1,000 lbs. of the whole bodies 

 of animals are as follows : — 

 Phosphorus 



pentoxide. Lime- Ratio. 

 Fat calf .. 15-35 1646 100 108 

 Half fat ox ... 18-39 21*11 100 116 

 Fat lamb ...11-26 12-81 100 114 

 Store sheep... 11-88 13-21 100 112 

 Store pig ...10-06 10-79 100 107 

 Fat pig ... 6 54 6'36 100 95 



Remembering that some of the phos- 

 phoric acid of the ash is present in the 

 food in the form of organic matter and 

 is utilised in the animal in the formation 

 of tissue other than bone (e.g., brain) and 

 to a greater extent than lime, it may 

 probably be assumed that the food of 

 an animal should contain about equal 

 parts of phosphorus pentoxide and lime 

 in its ash. 



In the two substances which form the 

 staple diet of horses and mules in 

 S. Africa — oat-hay and mealies, lime and 

 phosphorus pentoxide are present in the 

 ash in the following proportions : — 

 Phosphorus 

 pentoxide. Lime. 

 Oat-hay ... 100 77 



Mealies (maize grain) 100 4 



These are calculated from the ash 

 analyses of Wolff. In South African 

 grown oat-hay, I find that both the 

 lime and phosphorus pentoxide present 

 are smaller than in the average of 

 European samples, and that on the 

 average the ratio is 100 : 51. 



From the figures given by Warington 

 for the lime and phosphorus pentoxide 



in the whole of the oat-crop, the ratio is 

 100: 60. 



It is evident from the above figures 

 that the usual South African diet for 

 working animals does not supply lime 

 and phosphorus pentoxide in the propor- 

 tions which we have adcfuced reasons 

 for believing are best adapted for the 

 nutrition of bone. On the contrary a 

 ration consisting of oat-hay and mealies 

 provides a large excess of' phosphorus 

 pentoxide over lime. 



As to the injurious effect of the pro- 

 longed use of such a diet upon horses 

 and mules, we have no records of direct 

 experiments having been made, but in 

 1891, Weiske experimented with rabbits 

 on these lines. 



Adult rabbits, from the same litter, 

 were divided into four lots and fed 

 for three months upon : 



1. Hay , 



2. Mixture of hay and oats. 



3. Oats alone. 



4. Oats to which sodium dihydrogen 

 phosphate was added (so as to increase 

 artificially the ratio of phosphoric acid 

 to lime in the food). t 



It was noticed that the urine of rabbits 

 of lots 1 and 2 was alkaline, while that 

 of lots 3 and 4 was strongly acid. At 

 the end of the period the rabbits were 

 killed, weighed, and their skeletons 

 cleaned and weighed. 



The results were as follows, the 

 weights being grammes, 



Lotsl, 2, 3, 4. 

 Weight of bodies ... 2,430 3,420 2,030 1,810 

 Weight of skeletons ... 87 -66 115 80 69-28 63.76 



The bones of lots 1 and 2 were heavier, 

 stronger and richer in ash than those of 

 lots 3 and 4. Those of lot 4 were very 

 thin and breakable and contained a 

 smaller poroportion of lime and phos- 

 phoric acid than the others. 



In a later paper (1894), Weiske records 

 experiments in which the effects upon 

 the bones of animals feeding upon oats 

 alone were successfully neutralised by 

 the addition of carbonate of lime to the 

 diet. 



Another point of importance may be 

 here pointed out — the erroneous idea that 

 bran, which is almost universally re- 

 garded as being particularly rich in 

 " bone-forming material," i.e. ash, is use- 

 ful in adding bone formation. From 

 the point of view now under consider- 

 ation, bran would be a particularly bad 

 food, as the ratio of lime to phosphorus 

 pentoxide is extremely low — the actual 

 proportions present being approximate- 

 ly 0-3 per cent, of lime to 3 3 per cent. 



