162 Oat miff Tare Silar/e 



Furthermore, it must Ix' borm- in mind tliat in not one of the three cases 

 does the ether extract consist wholly of true fat. and also that the fat 

 dijjostion coefficients are lialtlo to be subject to error, in view of the fact 

 that the faeces always contain ether soluble material arising from meta- 

 bohc products and not from actual food residues. 



The nitrogen-free extractives of the hay and the silage are approxi- 

 mately of equal digestibihty, although in both cases the digestibility is 

 lower than that of the corresponding fraction of the green forage. The 

 depression of digestibility in this respect during the conversion of the 

 crop into hay and silage is not, however, so great as has sometimes been 

 supposed. 



It is interesting to note that the fibre constituent of the hay and silage 

 is almost equally digested, whereas that of the green crop possesses an 

 appreciably lower digestibihty. This finding confirms the supposition 

 that heating in the stack and the silo leads to a definite increase in the 

 dige.stibility of the crude fibre. In view of the fact that such fodders 

 contain relatively large amounts of fibre, this increase of digestibility 

 becomes of con.sidcrable significance. 



Attention should be called to the fact that whereas in the hay and 

 silage periods almost equal amounts of dry matter were fed per day, yet 

 in the green oats and tares period a much larger allowance of dry matter, 

 for reasons already gone into, was consumed by the sheep. It is well 

 known that animals tend to digest their food with somewhat less com- 

 pleteness when the ration undergoes any marked increase in bulk. This 

 variation is not necessarily very pronounced. Indeed, if it were, then 

 the digestion coefficients based on feeding definite rations (usually sub- 

 maintenance in such tests) could only possess a limited value. It is only 

 fair, however, in comparing the green fodder digestion coefficients with 

 those of the hav and the silage, to regard them as being minimum values, 

 and to assume that if a ration of green fodder more comparable in dry 

 matter content with the hay and silage rations had been fed. slightly 

 higher values would liave been obtained. Tliis does not affect greatly the 

 luain conclusion that the digestibility of the ]iay and silage dry matter 

 compares very favourably with that of the green fodder dry matter. 



The findings outlined above are substantially confirmed by a study 

 of the tabulated starch equivalents, which give the nutritive value of 

 100 lbs. dry fodder for production in terms of lbs. of starch. If anything, 

 these results point slightly in favour of the silage. 



The results giving the actual percentages of digestible nutrients in 

 the dry foodstuffs, whilst not strict!}- comparable owing to slight non- 



