SKIM-MILK. 157 



human food, and as a feeding material for swine and calves. This 

 will be dealt with further on. For general purposes, with the 

 exception of the manufacture of sour-milk cheese, the less free 

 lactic acid the skim-milk contains the better it is. Skim-milk is, 

 in the true sense of the word, a food, and belongs to the most valu- 

 able class of foods. It is obvious, of course, that its nourishing 

 value is narrower than that of milk, and that it is a one-sided 

 food. For this reason it is not suited for the nourishment of 

 children during their early life. Its value consists solely in the 

 percentage of proteids, milk-sugar, and mineral salts it contains. 

 The small quantities of fat which are present are hardly worth 

 taking into account. The skim-milk obtained by separators is 

 more valuable than that obtained in the older processes, since it is 

 characterized by greater cleanliness and freshness. 



In feeding pigs with skim-milk, according to the price of meat, 

 which ranges between 60 and 80 marks per 100 kilos, of live weight, 

 experience has shown that the kilo, of skim-milk may be taken to 

 have an average value throughout the year of about 3 pfennig. 

 If in different places its value is higher, it will be well not to rely 

 on speculative calculations, but to stick to the above price. 



The fresher the skim-milk is which is used as calves' food, and 

 the more fat it contains, the more nutritive will it be. With regard 

 to the value of skim-milk in this connection, average figures are 

 not of much general use. This is owing to the fact that it is strongly 

 influenced, not merely by the breed and treatment of the calf, by 

 the duration of the feeding, the condition of the market, and the 

 degree of care which has been bestowed on the young animal, but 

 also on a condition, which it is not easy to take into account, but 

 which has a great influence, viz. the fortune and the individual 

 good luck of the management in the treatment of the calves. In 

 the production of a kilo, of live weight the few experiments which 

 we have on the subject show that where skim-milk is used as the 

 sole food for calves, and where the feeding period lasts from 10 to 

 12 weeks, somewhere about 18 to 20 kilos, is necessary, that is, 

 somewhere about twice as much as would be required of whole-milk 

 for the same purpose. It has been often tried, by suitable additions, 

 to increase the nutritive value of the skim-milk, which has the very 

 narrow average nutritive ratio of 1 to T5. Good results have fol- 

 lowed the addition of linseed-oil to skim-milk in order to enrich it 

 in fat for feeding calves. Emulsions of fat in skim-milk, which 



