176 THE STOCKFEEDER'S COMPANION 



they grow inwards the contents of these cells are 

 apparently deposited inside the sac or alveolus. It is, 

 however, somewhat difficult to trace the walls of these 

 " shed " cells after, say, the second week of the lactation 

 period, and it is possible that they are dissolved in some 

 way or other, seeing the cell walls are so very thin. 



It is probable that the various constituents of blood 

 and lymph, as well as the substance of cell glands, are 

 all utilised in the formation of milk constituents. The 

 difference in composition of the fat of milk as compared 

 with that of blood may be accounted for by the 

 mammary glands first of all splitting up the fat in the 

 blood and then rebuilding or reconstructing it in such 

 a way as to give it the peculiar character of butter-fat 



(cp. p. 35)- 



Colostrum. The milk given during the first few 

 days after calving is of a rich yellow colour, glutinous, 

 and possesses laxative properties which nature considers 

 necessary for newly born animals. Chemically it is 

 very rich in albuminoids (16 to 18 per cent.), the greater 

 part of which is present in the form of albumen and 

 not casein, as is the case in normal milk ; hence a skin 

 rapidly forms on the surface of colostrum when it is 

 heated. At the same time it is poor in sugar (2\ per 

 cent). It gives a rich yellow colour to dairy produce, 

 but should not be used for butter till the end of the 

 first week ; and at least another week should transpire 

 before it is used for cheesemaking. 



It is not a good practice to remove the whole of the 

 milk from the udder during the first day after calving, 

 as there would be danger of the udder being chilled 

 by this sudden removal of milk which has been 

 accumulating for some days. The best plan is to 

 milk the cow three or four times during the first day, 



