XIV. FOODS AND FEEDING 305 



ration for horses and mules oat hay or oat hay and mealies it ex- 

 ceeds the lime greatly, in most cases the ratio being about 1 : 0'5. 



The author has good reason for concluding that many of the bone 

 diseases so prevalent in animals, and the sparse development of 

 bone which characterises the usual South African horse, are largely 

 attributable to their usual diet. As long ago as 1891, Weiske l showed 

 that rabbits fed on oats only, produced very small, weak, brittle bones, 

 while similar animals fed upon oats and hay developed normal skele- 

 tons. 



Whether the disease, osteoporosis, is really caused by the exclusive 

 cereal diet so often given to horses and mules in South Africa or not, 

 there can be little doubt that animals, now fed exclusively upon oat hay 

 or oat hay and mealies, would be far healthier and better nourished 

 if such foods as lucerne, or even grass hay, formed part of their diet. 

 The author's analyses show that many crops growing well in that coun- 

 try, e.g., cow peas, velvet beans, or even many grasses, would be far 

 preferable to oat hay from this point of view. 



It has not been sufficiently recognised that it is the composition 

 and not the amount of the ash constituents that is important in bone 

 formation. As an example of this fallacy, bran serves excellently. 

 This material is rich in ash and is often extolled on that account as 

 being peculiarly well fitted for bone nutrition. As a matter of fact it 

 contains about 3*3 per cent of phosphorus pentoxide and only about 

 0-3 per cent of lime, or 1 of phosphorus pentoxide to 0'09 of lime, and 

 from the point of view just discussed, ought to prove very unsuitable 

 for promoting bone formation. This is really the case, as is proved 

 by the existence of a peculiar bone disease known as "bran disease," 

 "shorts disease," or "miller's horse rickets," which is often observed 

 in millers' horses, and which is undoubtedly caused by feeding with 

 excessive quantities of bran. 



Another point of importance is the supply of adequate quantities 

 of the mineral ingredients required for the formation of the digestive 

 juices of an animal. 



Kellner estimates the daily requirement of a cow of average weight 

 at } to 1^ oz. common salt, that of a horse at \ to 1 oz., of a sheep or 

 pig at to oz,, but when foods difficult of digestion are used, these 

 quantities may be doubled. 



Kellner further estimates that for a fattening ox, 1 oz. of phosphorus 

 pentoxide and 2 oz. of lime per day per 1000 Ib. live weight are suffi- 

 cient, while with full-grown fattening sheep only 0*02 oz. and 0'2 oz. 

 per 1000 Ib. live weight per day, respectively, were thought to be suf- 

 ficient. With growing animals, these amounts are, doubtless, far too 

 small. 



In England, where the food of animals is usually very varied, the 

 necessity of supplying salt, though often recognised, is not so import- 

 ant perhaps as in South Africa, where in some districts the provision 

 of some form of " lick " is indispensable if the animals are to be main- 

 tained in health. So, too, for poultry, especially if kept in confine- 



1 Landwirtschaftliche Versuchs-Stationen, 39, 241. 



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