1922.] 



Fluctuations in Live Weight. 



679 



workers to master the art of clean milk production. It has been 

 found that such assistance is effectively rendered by holding 

 practical demonstrations on the farm followed by such lectures 

 as may be necessary to explain the why and wherefore of the 

 precautionary measures adopted, and by the organising of clean 

 milk competitions. Because of this experience, and because it 

 is expected that the farmers' need for such assistance will be 

 greater in the future than it has been in the past the Ministry 

 has recently addressed a letter on the subject to all County Edu- 

 cation Authorities in England and Wales (see p. 764). 



The articles by Mr. E. S. Beaven which recently appeared 



in the Journal on the subject of variety trials of cereals, point 



„, .. verv emphatically to the need for greater 



Fluctuations in v f J f n , • inl 



... care and accuracy m carrying out agricul- 



Weig . eX p eriments f one description. That 



equal care is needed in relation to another description of experi- 

 ments — feeding trials with cattle — may also be emphasised. 



For example, in the Agricultural Journal of India for May of 

 the present year, there appears an article entitled " Normal 

 Fluctuations in Body Weight of Bovines." It deals with a sub- 

 ject which is of great importance to all experimenters undertaking 

 feeding experiments with cattle. In carrying out such trials it 

 is sometimes the practice to record only initial and final weights 

 of animals under experiment. In determining these weights it 

 is generally considered sufficient to ascertain the fasted live 

 weight on one or two succeeding days at the beginning and close 

 of the experiment. In the case of the experiments under notice, 

 however, daily weighings were made of a number of animals 

 (buffaloes) for a period of 88 days. Charts are published showing 

 the daily variation of two animals, one set of a " control " and 

 the other of an animal receiving a fattening ration. These charts 

 show the most surprising changes from day to-day. For example, 

 we have such figures as the following on successive days : — 324. 

 329, 342, 336. 332. 329. 335 and (eleven days after) 305, 310, 

 320, 315 lb. Similar results were obtained from a large number 

 of animals. The principal conclusions arrived at are (1) that any 

 conclusions as to the suitability of a ration or feeding stuff when 

 based on data obtained from initial and final weighings, or 

 weekly or fortnightly weighings, are practically valueless, (2) that 

 weights should be taken daily, and conclusions based on the 

 averages of weighings of groups of at least ten successive days. 



