1922.] 



The Fattening of Cattle. 



409 



THE FATTENING OF CATTLE. 



A. 13. Bruce, M.A., Dip. Agric. (Cantab. ), 

 Ministry of Agriculture and Fisheries. 



A bulletin of more than ordinary interest on the above 

 subject," published by the Agricultural Experiment Station, 

 University of Minnesota, U.S.A., in 1920, has recently come 

 to hand. 



The mass of new and interesting data presented is almost 

 overwhelming, and only a very brief notice is here possible. 

 The experiments described in the publication began in 1907. 

 In all 189 head of cattle were employed. Of these 63 were 

 slaughtered at various stages from 100 lb. to 1,500 lb. live 

 weight. Complete analyses of the bodies of these animals 

 were made, the data including details of the composition under 

 such heads as Flesh, Edible Offal, Bone, Blood, etc. So far 

 as this country is concerned, the only data of this sort pub- 

 lished relate to three beasts only, slaughtered and analysed 

 by Lawes and Gilbert at Rothamsted in 1849. 



A unique feature of these experiments, however, is that all 

 the food employed from beginning to end was weighed and 

 analysed so that we have presented in this bulletin not only 

 the composition of the steers at each stage (each 100 lb. in- 

 crease of live weight) but also the analysis of all the food 

 consumed up to each stage in terms of protein, fat, etc. In 

 all 52 elaborate tables of figures are given, but, unfortunately, 

 the letterpress with which they are accompanied hardly does 

 justice to the unique value of the data wmich the investigation 

 provides. The tw T o accompanying figures have been constructed 

 to illustrate roughly some of the more outstanding results. 



Fig. T embodies some of the data obtained by analysing the 

 bodies of steers slaughtered at stages of 100 lb. from 100 to 

 1,500 lb. live weight. It shows in a graphic manner that: — 



1. After 600 lb. the fat laid on the edible portions of the 

 carcass rapidly increases, whereas the protein (roughly dry 

 matter of the lean meat) increases slowly and proportionately 

 to the increase of live weight. 



2. The rate of fat deposition begins to increase very rapidly 

 after 900 lb. is reached. 



3. Contrary to the usual opinion, the rate of fat deposition 

 in the offal is slower than that of flesh fat. and in absolute 

 amount is comparatively insignificant at all stages. 



* Investigations in Beef Production— University of Minnesota. Bulletin 

 193 — T. L. Haecker. 



