36 



Silage for Milk Production. 



[Apr., 



The following is the average analysis of several samples 

 tested by Mr. McLean, Lecturer in Agricultural Chemistry : — 



per cent. 



Moisture 7G.6U 



Crude protein (including 2"10 per cent true protein) ... 3'50 



Fat 1-05 



Fibre 9'15 



Ash 2-30 



Soluble Carbohydrates 7-40 



It will be noticed that these figures show a higher "content of 

 moisture and a lower percentage of carbohydrates than many 

 other published figures. This may be due to the exceptional 

 nature of the season of 1920, which was extremely wet and cold, 

 or it may be that silage produced in a west country district is 

 normally lower in feeding value than that produced in the drier 

 and more sunny eastern counties from which most of the avail- 

 able analyses have been obtained. 



Plan of Experiment. — The first step consisted in placing all 

 the cows at both farms on the same ration in order to enable 

 the selection for the experiment to be made. This preliminary 

 ration included a small amount of silage so as to accustom the 

 animals to it. Eight cows at each farm with approximately the 

 same total milk yield and comparable as regards age, date of 

 calving, etc., were then chosen. This was done after inspection 

 of the milk records for the 20th, 21st and 22nd of March. This 

 preliminary recording period of three days is admittedly short, 

 but it was -found necessary to curtail it as much as possible so 

 as to make it possible to complete the experiment by the end of 

 April, 



At the end of the preliminary period the rations of both lots 

 were gradually adjusted so that on the 27th March the Brook- 

 house cattle were on the full silage ration, and the Colomendy 

 cattle on the roots ration. This was continued for 14 days, 

 records of the milk yields being taken twice daily at both farms. 

 The rations were then gradually reversed so that in the second 

 period Colomendy cows received silage and the other lot had the 

 full root and hay ration. Seven days were allowed for the 

 gradual reversal of the rations. 



The following shows the plan of the experiment : — 



Brookh oum. Colomendy. 

 Preliminary period up to March 22nd ... Same rations. 



23rd to 26th March Transition. 



27th March to 9th April (14 days) ... Silage ... Roots. 



10th April to 16th April (7 days) ... Transition. 



17th April to 30th April (14 days) ... Roots ... Silage. 



