468 



EVENING DISCOURSES 



Grass Silage. — The practice of ensilage was introduced into Britain in 

 the 1840's, but did not get under way until the 'eighties. Since then it has 

 increased, but only to a moderate extent, although it is much used in other 

 countries — notably in New Zealand and Germany. 



Dr. S. J. Watson, of Jealott's Hill, has recently investigated the merits of 

 different methods of making silage. He has found that grass, whether 

 young and leafy or mature, may be made into silage. In order to prevent 

 excessive bacterial decomposition of young high protein grass in the silo, 

 it is necessary to keep the grass acid. This is done either by the addition 

 of hydrochloric and sulphuric acids, or, I believe better, by adding molasses 



Consumption of Grass, etc. 1935 



(crvt oP Crude Protein per acre) 



I 



m 



Foods not derived 

 from qrass 



Silaqe 



Hay 



Dried Grass 



Grazinq 



iZZZZZ23zzz 



^H 



VThTTi 



Jan Feb. Mar Apl May June July Aug Sept Oct Nov Dec 



Fig. 7. 



100 



5 



O 



O 



to the grass. The sugar of the molasses is fermented to lactic acid, which is 

 effective in keeping the mass acid. 



Grass Drying. — When Dr. Woodman discovered, or rediscovered, the 

 high protein content of young grass, he suggested its preservation by 

 artificial drying, and Prof. Wood got into touch with Sir Frederick Keeble, 

 who asked us at Billingham to dry some young grass. In 1927 we dried the 

 cuttings of cricket fields and made about five tons of dried grass for experi- 

 ments at Cambridge on feeding animals. 



Young grass containing perhaps 75 per cent, or 80 per cent, of water can 

 be dried to about 3 per cent, water by blowing a stream of hot air through 

 the grass. 



The dried grass is practically identical in feeding value with the original 

 grass. It is green, and contains the minerals and vitamins unchanged. 



As an example of the method of grass drying I will describe the Tednam- 

 bury Drier. 



