48 MILK [iv 



From the above table it will be seen that the total 

 solids ranged from 1540 per cent in the case of the 

 milk from the Jersey, to 12 '39 per cent in the case 

 of the Holstein a difference of 3 per cent. As 

 regards the fat, it will be seen that there is a difference 

 of 2 '15 per cent, the difference in total solids only 

 amounting to 3 per cent, which leaves less than 1 

 per cent for the variation in all the other constituents ; 

 or, to put it in another way, the percentage of fat in 

 the total solids ranged from 28 to 364 per cent, 

 while the percentage of " solids not fat " ranged from 

 8 3 "2 per cent to 6 3 '6 per cent. The variation in the 

 solids not fat only amounted to '71 per cent, viz. 

 from 9*80 to 9'0*7 ; and this variation was equal in 

 amount in the case of the casein and milk-sugar, 

 which varied between 3*39 per cent and 3 f 91 per 

 cent, and 4*84 to 5'33 per cent respectively. The 

 constituent which was most constant was the ash, 

 which only varied between /76 and -69 per cent. 



Period of Lactation. Another influence affecting 

 the quality of milk is the period of lactation that 

 is, the length of time after calving. And here it 

 may be pointed out that the duration of the lactation 

 period varies very considerably in the case of different 

 cows. In very rare cases, the secretion of milk may 

 actually continue without intermission from one 

 calving period to another ; while, on the other hand, 

 it may occasionally cease a comparatively short time 



