CHAP. v. AGE AT WHICH JERSEYS YIELD MOST BUTTER, 313 



The butter generally was of good colour and quality, but in the case 

 of two cows an excessive use of mangel had destroyed every trace of 

 colour. As regards the quality of the milk, it affords remarkable 

 testimony to the value of the Jersey cow for butter production. The 

 average yield of the twenty-eight animals tested was one pound of 

 butter from a trifle over six quarts of milk. 



The butter produce of Jersey Cows. From the time the English 

 Jersey Cattle Society made its first experiment in butter testing at the 

 Agricultural Hall, Islington, in October, 1886, up to 1897 inclusive, 

 many tests had been made, at which 745 Jersey cows, varying in age 

 from under two to over thirteen, years, had been put to proof. 



From a tabulated summary /of the results of these tests it appears 

 that the development of the Ibutter capacity is very gradual, and it 

 seems probable that even at the end of her fifth year the average Jersey 

 cow has not attained her maximum point of butter production. 



The milk yield, which, between the age of two and three years, 

 reaches an average of 2 gallons, or say 25 Ib. per day, continues to 

 increase till the ninth or the tenth year, when it stands at rather over 

 3| gallons, or 35 Ib. per day. At the same time, the butter shows a 

 corresponding increase from 1 Ib. 4 oz. to 1 Ib. 14 oz. per day. During 

 the whole of these eight years it appears that the average richness of 

 the milk varies but little from a standard of two gallons to the one 

 pound of butter. The average results from the 745 Jersey cows above 

 mentioned are : 



One day's milk ... 32 Ib. 6 oz., equal to 3 gallons a day. 

 One day's butter . . 1 Ib. llj oz. 



Butter ratio .... 19'02, about 16 pints milk to I Ib. butter. 

 Average days in milk, 70. 



At or about the age of six years the Jersey appears to attain her 

 prime. Her milk increases materially in richness, and her yield of butter 

 shows a proportionate advance. It seems probable that she maintains 

 this maximum value for some two or three years afterwards : 



Between 6 and 7 years, average butter ratio, 19 '14 Ib. 



7 and 8 years 18'66 Ib. 



8 and 9 years 19'12 Ib. 



This view of the prime age of the butter cow derives further confir- 

 mation from a comparison of the ages of those cows which succeeded 

 best throughout the series of ten tests that had been completed up to 

 May, 1890. These are as follows : 



Years. Months. Days. 



Average age of 10 first prize cows ... 7 o 10 



,, ,, 10 second prize cows ... 6 2 



,, ,, 10 third prize cows ... 5 8 2 



., 10 reserve number cows . . 5 5 8 



The total number of cows of nine years and upwards is too small to 

 afford a basis for judgment, but it is sufficient to warrant the statement 

 that some Jerseys maintain a high dairy value in their tenth year, or 

 even beyond. The summary table on the next page, extending over 

 twelve years, shows this. 



