32 THE SCIENTIFIC FEEDING OF ANIMALS 



For practical purposes, on the farm, straw conversion is conducted as 

 follows : 



1. Lehmann's Method (Goettingen) 



(a) Boil 6 to 8 hours in sodium lye in open iron kettles. 



(b) Boil 6 to 8 hours in closed tanks in sodium lye under pressure of 

 5 to 6 atmospheres. 



The first method is not followed by washing ; the second is followed by 

 washing. Yield, 53 per cent ; loss, 47 per cent. 



2. Colsmann's Method (Lindenberg) 



Boiling 5y^ hours in 8 per cent sodium lye in open kettles set in ma- 

 sonry. Yield, 58 per cent ; loss, 42 per cent. 



3. Beckmann's Method 

 Treating with 12 per cent sodium hydroxid solution in wooden tubs, 

 ordinary temperature, etc. Yield, 73 to 80 per cent. 



In methods 1 and 2 the straw is first run through a cutting machine 

 and chaffed. For each 100 lbs. of straw 200 lbs. of water and 10 lbs. of 

 sodium lye are added ; the mixture is then boiled, and after the mass has 

 been thoroughly drained the excess lye is washed out with fresh water 

 This, of course, entails loss of nutrients, to avoid which Thomann recom- 

 mends dispensing with the washing and neutralizing the mass by the addi- 

 tion of sour whey or fermented slops, sour ensilage, etc., and testing prod- 

 uct with litmus paper. The high lye content of the straw mass and the low 

 acid content of the neutralizing feeding stuffs necessitates the addition of 

 very considerable amounts of the latter to effect neutralization. The 

 product thus obtained is greedily eaten even by horses and swine. Swine 

 receive 3 lbs., horses 4.5 lbs., cattle 30 lbs. 



Converted straw, after the customary process of expressing the super- 

 fluous water, still has a moisture content of 70 to 75 per cent. 

 The dry matter has the following composition : 



Digestible 

 Per cent Per cent 



Organic matter 94.1 74 



Pure albumin 0.6 



Nitrogen-free extract 30.7 65 



Fat 1.0 32 



Crude fiber 61.8 82 



Mineral matter 5.8 



The digestible crude fiber is digested and assimilated as thoroughly and 

 completely as starch. 



The starch value in the dry matter is as follows : 



Per cent 



Ordinary straw 13.4 



Completely converted straw 85.0 



High-grade converted straw 65.0 to 70 



Moderately converted straw 50.0 to 60 



