PROPERTIES OF MILK 17 
milk. The following data obtained at the New Jersey 
Experiment Station illustrates these differences: 
T ; 
Breed. ee Fat. eae Proteids.} Ash. 
Per cent./Per cent./Per cent.|Per cent./Per cent. 
Ayshire........ 12.70 3.68 4.84 3.48 .69 
Guernsey ...... 14.48 5.02 4.80 3.92 75 
Holstein ....... 12.12 3.51 4.69 3.28 64 
FOTSCYsscte sce 5 14.34 4.78 4.85 3.96 15 
3. Extremes in the composition of milk are usually 
to be ascribed to the individuality or “make up” of the 
cow. It is inherent in some cows to produce rich milk, 
in others to produce poor milk. In other words, Nature 
has made every cow to produce milk of a given richness, 
which can not be perceptibly changed except by careful 
selection and breeding for a number of generations. 
Il QUALITY OF MILK AS AFFECTED BY ARTIFICIAL CON- 
DITIONS. 
1. When cows are only partially milked they yield 
poorer milk than when milked clean. ‘This is largely 
explained by the fact that the first drawn milk is always 
poorer in fat than that drawn last. Fore milk may test 
as low as .8%, while the strippings sometimes test as 
high as 14%. 
2. Fast milking increases both the quality and the 
quantity of the milk. It is for this reason that fast milkers 
are so much preferred to slow ones. 
