282 



THE ROTHAMSTED EXPERIMENTS, 



Difference will generally range from 70 to 75 per cent. In the case, 

 l <mdMten- now ever, of oxen fattened very young, and the feeding period 

 ing in- extending over a much longer time, similar calculations lead 

 crease. j. Q ^ e conc l us i on that the growing and fattening increase of 

 such animals may contain perhaps 2\ per cent or more of 

 mineral matter, against only about 1£ per cent over a limited 

 final period of more purely fattening increase ; about 10 per 

 cent of nitrogenous substance, against only 7 to 8 per cent in 

 the only fattening increase ; and perhaps only from 50 to 55 

 per cent of fat, against from 60 to 65 per cent in the more 

 exclusively fattening increase. In fact, whilst the growing 

 and fattening increase would consist of about two-thirds dry 

 substance and one-third water, that of the more purely fatten- 

 ing increase would consist of nearly three-fourths dry sub- 

 stance and only about one-fourth water." 



Similar results relating to sheep, lead to the conclusion 

 that during a final period of some months of feeding on good 

 fattening food, their increase will generally contain not less 

 than 2 per cent of mineral matter, and frequently more ; that 

 is distinctly more than in the case of oxen, the quantity 

 largely depending on the amount of wool. Of nitrogenous 

 substance, the final fattening increase of sheep will probably 

 seldom contain more than 7 per cent, and frequently some- 

 what less. In other words, notwithstanding the large amount 

 of nitrogen in the wool of sheep, their fattening increase will 

 probably generally contain less nitrogenous substance than 

 that of oxen. On the other hand, the increase of well fed 

 and moderately fattened sheep will generally contain nearly, 

 and sometimes more than, 70 per cent of fat, against an 

 average of less than 65 per cent in the case of oxen ; and 

 in the case of very fat sheep the percentage of fat in the 

 increase may even reach 75 per cent. 



Upon the whole, it may be assumed that the increase of 

 liberally fed and moderately fattened sheep, over several 

 months of final fattening, will probably consist of about 2 per 

 cent of mineral matter, about, or less than, 7 per cent of 

 nitrogenous substance, from 65 to 70 per cent of fat ; and in 

 all, of from 75 to 80 per cent of total dry substance ; whilst 

 the increase over the final period of excessive fattening may 

 contain from 70 to 75 per cent of fat, and from 80 to 85 

 per cent of total dry substance. 



Eef erring to pigs, the increase of those liberally and suit- 

 ably fed for fresh pork will probably, on the average, contain 

 — an immaterial amount of mineral matter, only from 6| to 

 7 1 per cent of nitrogenous substance, from 65 to 70 per cent 

 of fat, and from 70 to 75 per cent of total dry substance. The 

 increase over the last few months of high feeding of pigs fed 



