CAROTIN, THE PRINCIPAL YELLOW PIGMENT OF MILK FAT 379 



especially true when the fat production and the actual proportion of 

 the ration furnishing the pigments are taken into account. Such a 

 comparison is shown in Table 19. 



TABLE No. 19. RELATIVE COLOR PRODUCTION UNDER SPECIAL FEEDING 



CONDITIONS. 



(a) Per cent of moisture free green feed in total ration. 



The most interesting feature of the above table is to note that 

 on the basis of the per cent of green dry matter in the ration, the 

 Jersey cows produced the highest colored fat because they received 

 the highest per cent of green dry matter. By taking into considera- 

 tion also the difference in fat production, an interesting calculation 

 can be made with the figures of average color, fat production and per 

 cent of green dry matter in the ration, which will cause the relative 

 color production of the two breeds to approach almost unity. 



If it be assumed for the moment that there is no breed charac- 

 teristic we can say that 30% green feed in the ration of the Holsteins 

 produces 18 units of yellow in the fat for the same reason that 42% 

 green feed in the ration of the Jerseys produces 29 units of yellow 

 in their fat. If this is true then the following proportion would be a 

 true one, i. e. : 



42:29 : : 30:18 



The product of the means is not quite equal to the product of the 

 extremes but gives the result, 



870 = 756 



