1920.] 



Feeding Value of Silage. 



277 



THE COMPOSITION AND FEEDING 

 VALUE OF SILAGE. 



The steady extension of the practice of ensilage in this 

 country in recent years has made it desirable that the meagre 

 information hitherto available as to the composition and feeding 

 value of silage should be supplemented as far as possible. The 

 older analyses can hardly serve as a reliable guide to present-day 

 practice, in view of the greater variety of crops and the improved 

 methods of preparation now used. 



With a view to initiating the collection of reliable data 

 arrangements were made by the Food Production Department 

 in 1918 for obtaining from various sources samples of silage 

 made in 1918-19. The analysis of 17 samples was kindly 

 undertaken by ]\Ir. Gwilym Williams, of the School of Agri- 

 culture, Cambridge, and his results are summarised on p. 280. 

 Estimates of the relative feeding values are also given, these 

 estimates being based upon the composition and digestibility 

 of the materials. 



Moisture. — Attention may be directed first to the fact that there 

 was great variation in the proportion of moisture in the 17 

 samples (ranging from 58' 4 per cent, to 8t 62 per cent.) ; and 

 conversely to the percentage of dry matter (ranging from 41* 6 

 to 18-38 per cent.). The highest percentage of moisture (8i'62) 

 is accounted for by the fact that this sample was a maize 

 silage, the thick, fleshy stems and leaves of this crop inevitably 

 carrying a large proportion of water into the silo. The three 

 driest samples were all from one farm, and it would seem that 

 either the crop was allowed to ripen to an appreciable extent 

 before cutting, or was dried somewhat before transferring 

 to the silo. 



Apart from these four samples the percentages of moisture 

 are distributed fairly uniformly between the limits of 67 per cent . 

 and 78 per cent., which may, perhaps, be regarded as the normal 

 range of variation, with an average in round hgures of 73 

 per cent, moisture, or 27 per cent, dry matter. 



Albuminoids or Protein. — The albuminoids (or protein) of 

 feeding stulfs always possess a special importance, since they 

 have certain bodily functions to sustain which no other 

 ingredient can support. 



In some analyses a distinction was made between " crude 

 albuminoids " (or crude protein) and pure albuminoids (or 

 pure protein). The former represents the total nitrogenous 



U 



