FEEDING OF ANIMALS. 321 



sted here}, averaging about 42 cows, almost exclusively Period of 

 Shorthorns, in each month of the year, over six years, 1884- y C ^[ d a ^ d 

 1889 inclusive ; and the succeeding columns show the quality of 

 amounts of butter-fat, of solids not fat, and of total solids, in milk - 

 the average yield per head per day in each month of the 

 year, calculated, not according to direct analytical determina- 

 tions made at Rothamsted, but according to the results of 

 more than 14,000 analyses made under the superintendence 

 of Dr Vieth, in the laboratory of the Aylesbury Dairy Com- 

 pany, in 1884 ; x the samples analysed representing the milk 

 from a great many different farms in each month. 



It should be stated that the Rothamsted cows had cake Food 

 throughout the year ; at first 4 lb. per head per day, but after- allowed - 

 wards graduated according to the yield of milk, on the basis 

 of 4 lb. for a yield of 28 lb. of milk, the result being that 

 then the amount given averaged more per head per day 

 during the grazing period, but less earlier and later in the 

 year. Bran, hay, and straw-chaff, and roots (generally man- 

 gels), were also given when the animals were not turned out 

 to grass. The general plan was, therefore, to give cake alone 

 in addition, when the cows were turned out to grass, but 

 some other dry food, and roots, when entirely in the shed 

 during the winter and early spring months. 



Referring to the column showing the average yield of milk Greater 

 per head per day each month over the six years, it will be Wilkin 

 seen that during the six months — January, February, Sep- summer 

 tember, October, November, and December — the average thanwin 

 yield was sometimes below 20 lb., and on the average, only 

 about 21 lb. of milk per head per day ; whilst over the other 

 six months it averaged 27.63 lb., and over May and June 

 more than 31 lb., per head per day. That is to say, the quan- 

 tity of milk yielded was considerably greater during the 

 grazing period than when the animals had more dry food, 

 and roots instead of grass. 



Next referring to the particulars of composition, according Variations 

 to Dr Vieth's results, which may well be considered as typical l^of^niik 

 for the different periods of the year, it is seen that the specific at different 

 gravity of the milk was only average, or lower than average, 

 during the grazing period, but rather higher in the earlier and 

 later months of the year. The percentage of total solids was 

 rather lower than the average at the beginning of the year, 

 lowest during the chief grazing months, but considerably 

 higher in the later months of the year, when the animals were 

 kept in the shed, and received more dry food. The percent- 

 age of butter-fat follows very closely that of the total solids, 



1 The Analyst, April 1885, vol. x. p. 67. 

 VOL. VII. X 



seasons. 



