FARM DAIRYING 



happen to both teats on the same side, half of her 

 usefulness as a milker is gone. 



The birth of the young is the primary incentive 

 to the secretion of milk by all animals which suckle 

 their young. In the wild animals and in the scrub 

 cow the udder is small and imperfectly developed, 

 and secretes milk only for a few months. Intel- 

 ligent feeding, selection, and breeding have re- 

 sulted in an enormous development of udder, and 

 an almost continuous milking period in the best 

 cows. 



There are two general theories advanced in re- 

 gard to the secretion of milk. The metamorphic 

 (meaning change of form) claims that the milk is 

 due to a breaking down of the cell structure of the 

 udder. We can hardly accept this, for it would be 

 almost impossible for a cow to build up and break 

 down the cells to the extent of as high as from 

 fifty to one hundred pounds of milk per day. 



The transudation, or filtering, theory claims that 

 the milk filters or oozes through the tissues from 

 the blood as it courses through the udder. Neither 

 can this explanation be wholly true, for constituents 

 found in milk are almost lacking in blo_od — fat, 

 for example. 



A combination of these two theories appears 

 reasonable. As the blood courses through the 



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