DIET OF BREEDING COW. 559 



tion. The increase in the quantity of the butter shown in the 

 above experiments, when the cow was in part fed on potatoes, 

 indicates the formation of fat from starch. This fact stands 

 in contrast with the opposite fact, that the proportion of 

 caseine is increased when beans and oatmeal enter largely 

 into the food. 



Connected with the interesting object of obtaining a con- 

 tinued supply of milk from the cow, there is a very singular 

 belief that has not yet obtained an attention commensurate 

 with its importance. If the functions of the organs concerned 

 in lactation have been once called into full activity by the act 

 of breeding in the cow, it would appear that the function of 

 the ovaries may be put an end to, and yet that those of lacta- 

 tion may continue in uninterrupted vigour for years. This is 

 the theoretical foundation of a proposal to remove the ovaries 

 from (to spay) a young cow after its first calf, subsequently to 

 which proceeding it is said to afford milk uninterruptedly for 

 many years. 



Theory of Feeding the Cow during Gestation. The obser- 

 vations made with respect to the necessity of attention to the 

 food of the mare during the state of gestation equally apply to 

 the cow when in that condition. During the chief part of 

 gestation the cow has not merely to nourish her offspring in 

 the womb, but also to yield a supply of milk to her owner. 

 This supply of milk she yields when in the unimpregnated 

 state in great abundance even for a succession of years ; and 

 such a supply generally continues un diminished during the 

 earlier months of pregnancy. During the later months the 

 secretion sensibly diminishes, and for some weeks previous 

 to parturition it is, for the most part, entirely suspended. It 

 appears that, on an average of cases, by the fifth month of con- 

 ception a diminution of one-third of its quantity has taken 

 place ; by the sixth month, two-thirds ; and soon after the 



