FOOD AND MILK 189 



When the amount of concentrated food has reached 

 a certain point, any increase in this amount does not 

 give a corresponding increase in the yield of milk. 

 In fact, in the Offerton Hall (Durham) experiments 

 it appears that when the concentrated food was in- 

 creased from 8 to 12 Ibs. per 1000 Ibs. live weight per 

 day, the milk-yield was only increased by 2 pints per 

 day, which must be considered a very small increased 

 yield for an increase of 4 Ibs. of concent-rated food per 

 head per day. 



The relative proportion of the nutrients in the con- 

 centrated mixture appears to have some effect on the 

 composition and quality of milk and butter. E.g., in 

 experiments carried out by the Midland Dairy Institute 

 in 1896, with a basal ration of 50 Ibs. roots, 10 Ibs. chaff, 

 and 6 Ibs. hay per day, when the ratio of digestible fat 

 (from linseed cake) to albuminoids in the ration was 

 as 1:3, it appeared to increase the proportion of 

 fat in milk, but the butter made from it was soft 

 and inferior compared with that obtained when the 

 proportion of fat to albuminoids in ration was as 

 1:6. 



Dr Crowther states in his 1906 report that "heavy 

 feeding of cakes rich in oil say upwards of 4 Ibs. per 

 day tends to lower the proportion of volatile (fatty) 

 acids, or in other words to increase the amount of 

 margarine-like ingredients of the butter-fat." This 

 supports the results obtained at the Midland Dairy 

 Institute- 

 When "decorticated cotton cake or meal" is in- 

 cluded to a greater extent than, say, one-third of the 

 concentrated food given, it tends to give a hard, pale- 

 coloured butter with a tallowy sort of flavour. " Linseed 

 cake," on the other hand, if rich in oil, gives a softer 



