276 THE CHEMISTRY OF CATTLE FEEDING 



is generally given only to young or sick animals, and then it 

 usually forms a large proportion if not the whole of the ration. 

 The cake is usually fed in a dry state to healthy adults, and 

 only small quantities are used. If the mash is made with 

 boiling water and kept as hot as possible for an hour or two 

 before it is used, the enzyme will probably be rendered inactive* 

 and danger is reduced to a minimum. 



Nitrogenous glucosides which yield prussic acid on hydro- 

 lysis have also been found in the seeds of many other plants, 

 amongst which may be mentioned the great millet, Java beans, 

 Cassava, vetch, and the Para rubber plant. Oil is extracted 

 from the last, and the residue is sold as a feeding cake. 



Cotton Cakes. The seed of the cotton plant contains the 

 woolly cellulose fibre which is spun and woven into ordinary 

 cotton. It belongs to the class of oily seeds, and, when the 

 cotton has been removed, the oil is expressed, and the residue 

 is sold for cattle feeding under the name of cotton cake. 

 There are several varieties of this product, and they differ 

 greatly in composition and properties according to the treat- 

 ment to which the seed is subjected. In America, the hull 

 or cortex of the seed is first removed. This permits of a very 

 complete separation of the cotton, and the cake which remains 

 when the oil has been expressed, contains little but the actual 

 nutrients of which it is composed. It is known as American 

 or decorticated cotton cake. It is one of the most highly 

 concentrated, most readily digestible, and, at present rates, 

 one of the cheapest cakes on the market (cf. pp. 166, 213). 

 With the possible exception of linseed cake, probably none 

 are more appreciated by the animals. 



The Egyptian and Indian (Bombay) seeds are treated in 

 a different manner. The cortex is not removed, and the 

 cotton cellulose cannot be completely extracted. Unde- 

 corticated cotton cakes the deoiled residues therefore con- 

 tain nearly three times as 'much crude fibre, and only about 

 half the percentages of oil and albuminoids commonly found 

 in the American cakes. The coefficients of digestibility and 

 nutritive value are consequently much lower. 



Undecorticated cotton cakes are sold at lower prices per 



