ILLINOIS STATE DAIRYMEN'S ASSOCIATION. 24 



The general principle appears to hold in the yield of fat as in the 

 yield of milk; namely, that the greater yield is from the longer period. 

 Yet there are three exceptions: one of Jock as she is going dry, one of 

 Lady Pietertje in July in which she yielded 2^ per cent more fat in 

 the shorter period, and one of Eva in the same month with a slight 

 excess in favor of the evening "milking. Again, it is interesting to notice 

 below the rate at which this fat has been manufactured per hour during^ 

 both the longer and the shorter periods: 



Table 4. Yield of fat calculated in pounds per hour, morning and 

 evening milk. 



JOCK DOLLY EVA JANET t^^^^^. 



Pietertje 

 a. m. p. m. a. m. p. m. a. m. p. m. a. m. p. m. a. m. p. m^ 



May 038 .040 .039 .039 .026 .029 .039 .039 .046 .05^ 



June 027 .030 .038 .037 .024 .026 .039 .039 .041 .043 



July ..'.. .005 .008 .032 .037 .019 .023 .034 .038 .033 .040 



Even more pronounced than in the case of milk, the calculated 

 hourly manufacture of fat is greater in the shorter period. Out of the 

 fifteen cases there are but three exceptions. In two of these the secre- 

 tion per hour is the same for the two periods and in the remaining- 

 instance the excess in favor of the longer period is but .0001 of a pound 

 per hour, a difference that is insignificant. On the contrary the differ- 

 ences in favor of the shorter period are pronounced and in one instance 

 it is .007, or seven times as great as the greatest difference in favor of 

 the longer period. The evidence is unmistakable, and to the effect that 

 the rate of secretion of fat is more rapid for the shorter period. 



Because of the considerable excess in time in favor of the long 

 period more fat was yielded at the morning milking, and yet the ten- 

 dency to greater production of fat during the shorter time was sa 

 marked that in nearly every case the average per cent of fat was higher 

 for the evening milking. 



Table 5. The average per cent of fat, morning and evening milk. 



