144 ILLINOIS STATE DAIRYMEN'S ASSOCIATION 



and fat stock shows by a careful observation of the cattle ex- 

 hibited. 



On the other hand, when the real dairy cow has digested 

 her food the blood is pumped out from the heart past the di- 

 gestive apparatus, picking up the digested nutrients and carry- 

 ing them, not up on top of their backs, but around through the 

 udder where milk and butterfat are made. The first indication 

 of the amount of blood passing into the udder is at the 

 escutcheon, a portion just above the rear of the udder where the 

 hair grows upward on each side of which the hair grows down- 

 ward. It is believed that the hair covering the escutcheon is 

 nourished by the blood in the vessels which are passing to the 

 udder. An indication which determines more accurately the 

 amount of blood passing through the udder is found in the mam- 

 mary veins. All cows have two of these veins, one on each side 

 of the abdomen. Some cows have straight short veins ending in 

 a small milk well. Other cows have veins that are large and 

 tortuous, extending far forward, as do the veins of this cov/, to 

 a large milk well, an opening in the abdomen large enough to 

 insert my thumb, and passing on to a second milk well, and some- 

 times on to a third or fourth. These are termed double exten- 

 sion veins. Some cows have three veins, one extending forward 

 from the udder along the center of the abdomen between the 

 two outside veins. Such a vein is termed a center extensiori. 

 The size, length and tortuousness of these veins, together with 

 the number and size of milk wells when found passing forward 

 from the udder of the cow, indicates the amount of blood thn<- 

 is circulated past the digestive apparatus picking up food nutri- 

 ents, carrying them to the udder and, being rid of its load, is on 

 the way back to the heart and lungs for purification and to be 

 pumped back again. I have never seen a good cow with small, 

 short, straight mammary veins, and I have never seen a cow 

 with large, tortuous veins and large, numerous milk wells that 

 was a poor cow. A consideration of the blood flow will deter- 

 mine largely the character of a cow from the standpoint of milk 

 and butterfat production. Feed deposited on the back of the 

 cow can not be made into milk, and on the other hand, feed that 



