CHAPTER XXVIII. 



Failure of Deep Milkers, to Breed. 



// results from Chronic Relaxation of the Matnmary Ar- 

 teries. 



We have seen questions relating to the difficulty of dry- 

 ing certain cows, generally deep milkers, and asking ad- 

 vice through the agricultural press, in several instances ; 

 and, also, numbers of such cows. They are scattered over 

 the country, and consist, chiefly, of cows of large yield, 

 that are dried up only with great difficulty ; and there are 

 some cases in which such cows cannot be dried, without 

 reducing their feed almost to starvation rations. In such 

 cases it is quite clear the cows have lost control over their 

 mammary blood flow ; their udders are, most of them, re- 

 laxed, while their udder-supply arteries are large in the ex- 

 treme; and as certainly relaxed, because it is very evident 

 they do not contract ; and therefore the blood-flow to the 

 udder is not reduced, or diminishes but little, and slowly, 

 and does not cease, as it does in cows that dry themselves 

 by artery contraction while they are breeding. It is evi- 

 dent, therefore, that those cows which cannot be dried 

 early, and do not breed, are affected with chronic relaxa- 

 tion in the arteries that supply the milk glands with the 

 breeding blood ; the flow of which to the udder is not ar- 

 rested. 



These cows of deep yield cannot be easily dried, be- 

 cause the large size of their udder-supply arteries remains 

 fixed by relaxation. The arteries cannot be closed at the 



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