THE ROTHAMSTED EXPERIMENTS.

Otago Witness, Issue 2396, 1 February 1900, Page 4

THE ROTHAMSTED EXPERIMENTS.

The Rothamstead experiments are so frequently quoted by authors of text books and other prominent writers on agricultural topics as authoritative on the important question of the economical and profitable feeding of the animals on the farm, that obviously the illustrations and results of the investigations must long continue valuable -for reference. Therefore it is that abstracts of a few of them which bear directly on the most important branches of the stock-keeping industry ia the colony have been given a place in these columns, so that those engaged in the pursuit may have a clear conception of the conditions contributory to systematic practice ir» regard to it, and that the information as reproduced may be preserved for reference as occasion may axise. One of the most important of the investigations involved the^ determination of the percentages of water, mineral matter, fat, and nitrogenous substances in certain separated parts and in the entire bodies of 10 animals — namely, 1 calf, 2 oxen, 1 lamb, 4 cheep, and 2 j>igs. Complete analyses of the ashes, respectively, of the entire carcases, of the wised internal and qtUer "offal" parts.

and of the entire bodies of each of these 10 animals have also been made. The following is a table of results : — Percentage composition of the carcases, the offal, and the entire bodies of 10 animals of different descriptions, or in different conditions of maturity.

From- the data provided, as above described, as to the chemical composition of the different descriptions of animals, different conditions of age and fatness, the composition of the increase while fattening and the relation of the constituents stored up in the increase to those consumed in food have been estimated. It is admitted that the conditions do not cover adl the variations of composition occurring in actual practice ; but, at the same time, there can be no doubt that by the aid of such factors the feeder would be enabled to calculate, with sufficient approximation to the truth for all 'practical purposes, the composition of the store animals he buys and sells and of the fat ones he sells.

It is impossible to go into any detail here, either as to the composition of the animals at the different stages, or as to the estimated composition of Cheir increase, but the results may be briefly summarised as follows : —

limuwa ; — In the case of oxen, the figures representing the progress of animals at different stages of progress show • that the percentage of mineral matter ranged from 5.15 in the store to only 3.45 in the very fat condition, that of the nitrogenous substance from 18.0 in the store to only 3.43 in the very fat condition. Again, the percentage of total dry substance increases from only 34.8 ia the store to 54.0 in the very fat condition. Lastly, the percentage of water decreases from the store to the very fat condition.

The parallel results from sheep show that the percentage of mineral matter ranged from 3.25 in the store to only 2.90 in the very fat animal ; the nitrogenous compounds from 15.5 per cent, in the store to only 10.9 per cent, in the very fat condition ; and against these reductions the fat increases from 14.5 per cent, in the store to 45.8 per cent, in the very fat condition ; and the total dry substance from 33.2 per cent, to 59.6 per cent. There is, therefore, a lower percentage of total dry .substance in the store sheep than in the store ox, owing to the less amount of mineral and nitrogenous matter in the store sheep. There is, on the other hand, a higher percentage of dry substance in the very fat sheep than in the very fat ox, owing to the higher percentage of fat in th.c sheep. Lastly, in the sheep, the percentage of water diminishes from the earliest to the latest stage from 60.8 to only 35.2. The results relating to the composition of pigs showed a reduction in the percentage of mineral matter from 2.93 in the store to only 1.14 in the very fat condition ; and a reduction in that of nitrogenous substance from 14.4 in the store to 9.5 in the very fat .state. But, instead of a reduction, there is an increase in the percentage of fat from 18.6 in the store to 51.6, or to more than half the weight of the body, in the very fat condition ; and there is an increase in the percentage of total dry substance from 35.9 in the store to 62.2 in the very fat condition ; and (excluding stomach and contents, etc.) a reduction in the percentage of water from 58.6 to 34.4.'

The results relating to the chemical composition of the different animals, in different conditions as to age and maturity, have shown, however, that even store animals may contain more of the non-nitrogenous substance — fat — than of nitrogenous substance ; whilst the bodies of fattened animals may contain two. three, four, or even more times as much dry fat as dry nitrogenous matter. It has further been shown that the proportion of fat to nitrogenous matter in the increase in live weight of the fattening animal is much higher than in the entire bodies of the fattened animals. If, therefore, the nonnitrogenous substance of the increase — the fat — is derived from the non-nitrogenous constituents of the food, the relatively large demand for suck constituents for the produc-

tion of fattening increase would seem to ba amply accounted for.

Fat calf ...i 3'Bi Ea'ffatox... 4-66 Fat ox ... 392 b'atUiub ..I 294 3toie sheep 316 tialf-fat old the p ... 3-17 Fa' shoep ... 2 - 8 l hi xt r a fat shtep ... 2*.-0 3to:epig ... 267 feat pig ... 165 BteoDS of all 317 we 14-5 li' 3 14-8 191 301 28-5 18 7 33-8 | 4 <•:■} 48-5 4J7 3f!7 t-3-0 5f5 4V5 478 57-3 3 17 819 5 98 8-54 6 00 14 0 12 2 23 5 ! 35-6 40 7 Lots 50 - 2 43 4 9.05 e-o^ 10-9 137 10-9 45-8 2V3 42 2 50-6 397 547 352 55-1 413 5-18 5-22 397 i " i .:«■•> ■44 9 49-0 I 6-13 !■•>

Fat calf .. Half- fat ox . Fat ox Fat la»ib ... Store sheep Half-fat old sheep Fat bheep ... Kxtra fit Bheep iStcepig ... Fat pig 3-41 4-05 3 40 2-45 219 2 72 2-32 ! 171 1 20(5 175 18 9 18 6 177 Its-1 14-0 33 T 15 7 40 4 2o\* 47-2 201 41-5 16 1 36 8 18-5 38 9 £64 M-8 K4 2 59 « 528 58 5 63-7 611 55-2 3-64 307 21>7 16-8 140 14-S 34 5 54-9 15-0 | 32": 22 8 I 466 21-0 I 412 I 451 67-9 SJ-4 3-02 17 2 i _i I SS-8 I i i tfeam of all I _

Half-fa 1 ; 0x... Fat ox Fat lamb .. Stnre sheep Half-fat old sheep Fat sheep .. Kxtra fat sheep 3 bore pig ... Fat pig 5-56 4 56 3 6i 4-36-ibfi 17 8 15-0 10 0 14-5 16 6 22-6 34-8 36 9 23 8 377 46 0 514 51-4 427 US i) 54-0 45 6 48 6 57 3 4-12 3-45 14 9 11-5 31-3 45-4 50-3 603 49 7 397 2 77 2-57 14( ) 9-1 J4-0 10-5 551 281 495 67 0 4i7 6C4 33 0 55-3 38-fi I - - Means of all. i 3-69 I I I 135 i I 34- 4 i_ I 51-6 48-4 —

I o s .2 "S n 2T ¥ s g o a 5 i o s to t a 5 a « , 33 o C$ .i-t G O -S g 11c -S SS c.S II

'er cen' ;. in carcase.

'er cent, in offal (excluding contents of stomachs and intestines).

'er cem in 1 the entire animai weight) . [US' livi